Matters of the Variable Heart: Respiratory Sinus Arrhythmia Response toMarital Interaction and Associations With Marital Quality

Timothy W. Smith and Matthew R. CribbetUniversity of Utah

Jill B. Nealey-MooreUniversity of Puget Sound

Bert N. Uchino, Paula G. Williams,and Justin MacKenzie

University of Utah

Julian F. ThayerThe Ohio State University

Maintenance of relationship quality requires self-regulation of emotion and social behavior, and womenoften display greater effort in this regard than do men. Furthermore, such efforts can deplete the limitedcapacity for self-regulation. In recent models of self-regulation, resting level of respiratory sinusarrhythmia, quantified as high-frequency heart rate variability (HF-HRV), is an indicator of self-regulatory capacity, whereas transient increases in HF-HRV reflect self-regulatory effort. To test thesehypotheses in marriage, 114 young couples completed measures of marital quality and a positive, neutral,or negative initial marital task, preceded and followed by resting baseline assessments of HF-HRV.Couples then discussed a current marital disagreement. Resting HF-HRV was correlated with maritalquality, suggesting that capacity for self-regulation is associated with adaptive functioning in closerelationships. For women but not men, the negative initial task produced a decrease in resting HF-HRV.This effect was mediated by the husbands’ negative affect response to the task and their ratings of wivesas controlling and directive. When the subsequent disagreement discussion followed the negative initialtask, women displayed increased HF-HRV during the discussion but a decrease when it followed theneutral or positive task. The valence of the initial task had no effect on men’s HF-HRV duringdisagreement. Negative marital interactions can reduce women’s resting HF-HRV, with potentiallyadverse health consequences. Women’s reduced health benefit from marriage might reflect the depletingeffects on self-regulatory capacity of their greater efforts to manage relationship quality.

Keywords: heart rate variability, respiratory sinus arrhythmia, marital interaction, self-regulation, maritalconflict

Marriage is the central personal relationship for many adults,with important consequences for health and well-being. Marriedpeople live longer than the unmarried and are less prone to seriousillnesses (Kaplan & Kronick, 2006), although this benefit is oftengreater for men than women (Eaker, Sullivan, Kelly-Hayes,D’Agostino, & Benjamin, 2007; Kiecolt-Glaser & Newton, 2001).Marital quality is also important, as marital strain and conflict,separation, and divorce confer risk of emotional difficulties andserious physical illness, (Beach, 2001; De Vogli, Chandola, &Marmot, 2007; K. A. Matthews & Gump, 2002; Tobe et al., 2007).

Models of these associations identify physiological stress re-sponses as a key mechanism (Kiecolt-Glaser & Newton, 2001),

including cardiovascular, neuroendocrine, and immune changesreflecting the sympathetic nervous system and hypothalamic–pituitary–adrenocortical system. Marital conflict evokes increasesin heart rate and blood pressure (Nealey-Moore, Smith, Uchino,Hawkins, & Olson-Cerny, 2007; T. W. Smith et al., 2009), a set ofresponses commonly labeled cardiovascular reactivity (Chida &Steptoe, 2010; Schwartz et al., 2003). Marital conflict also evokesrelease of stress hormones (e.g., cortisol) and inflammatory factorsin the immune system, as well as suppression of other immunecomponents (Kiecolt-Glaser et al., 2005; Robles & Kiecolt-Glaser,2003). Repeated over time, these responses can promote the de-velopment of life-threatening diseases. Women often displaygreater physiological reactivity to stressful marital interactionsthan do men, perhaps contributing to their smaller health benefitfrom marriage (Kiecolt-Glaser & Newton, 2001).

Recent theory and research on self-regulation and closely re-lated parasympathetic nervous system mechanisms suggest an-other pathway linking marital quality with health, one that couldcontribute to women’s reduced marital benefit. Specifically, wom-en’s greater efforts to maintain relationship quality could conferrisk by depleting protective self-regulatory resources. That is,women might be not only more stressed than men by difficultmarital interactions but also more drained or depleted by efforts to

This article was published Online First October 18, 2010.Timothy W. Smith, Matthew R. Cribbet, Bert N. Uchino, Paula G.

Williams, and Justin MacKenzie, Department of Psychology, University ofUtah; Jill B. Nealey-Moore, Department of Psychology, University ofPuget Sound; Julian F. Thayer, Department of Psychology, The Ohio StateUniversity.

Correspondence concerning this article should be addressed to TimothyW. Smith, Department of Psychology, University of Utah, 380 South 1530East (Room 502), Salt Lake City, UT 84112. E-mail: tim.smith@psych.utah.edu

Journal of Personality and Social Psychology © 2010 American Psychological Association2011, Vol. 100, No. 1, 103–119 0022-3514/10/$12.00 DOI: 10.1037/a0021136

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manage or avoid such difficulties. Self-regulatory capacity andefforts to regulate the emotional tone of marital interactions shouldbe evident in parasympathetically mediated heart rate variability,and these parasympathetic responses are an important influence onhealth (Thayer & Lane, 2007, 2009). Hence, parasympatheticallymediated heart rate variability can provide a useful indicator ofregulatory capacity and effort in close relationships, as well as aplausible link to health outcomes. The present study examinedassociations between marital quality and this parasympathetic in-dicator of self-regulatory capacity, as well as the effects of poten-tially stressful marital interactions on this mechanism.

Marriage and Self-Regulation

Maximizing positivity, warmth, intimacy, and support and min-imizing negativity and conflict in marriage often require effort toregulate the tone of potentially stressful interactions (Halford,Lizzio, Wilson, & Occhipinti, 2007; Lindahl & Markman, 1990).Such efforts help avoid cycles of negative behavior and emotionthat otherwise undermine marital quality and typify troubled rela-tionships (Fincham & Beach, 1999; Snyder, Heyman, & Haynes,2005). Efforts to protect and enhance marital quality includeinhibiting angry or aggressive impulses, suppressing verbal orfacial expression of negative affect, attempting to calm one’sspouse, enacting more constructive alternatives in problem solv-ing, and balancing discussion of negative issues with positivecontent. These processes are described under several labels, in-cluding emotion regulation in couples (Snyder, Simpson, &Hughes, 2006), relationship self-regulation (Halford et al., 2007),controlled interpersonal affect regulation (Niven, Totterdell, &Holman, 2009), and emotion work (Erickson, 2005), and they arekey influences on marital quality (Lindahl & Markman, 1990).Furthermore, individual differences in such self-control abilitiesare related to several adaptive interpersonal and relationship pro-cesses (Tangney, Baumeister, & Boone, 2004). Thus, greater skillor capacity in self-regulation seems likely to promote maritalquality.

Self-regulation in marriage and other close relationships gener-ally differs for men and women. Women are often more attentiveto relationship quality (Acitelli, 1992; Nolen-Hoeksema & Jack-son, 2001). They also often expend more effort in managing theemotional climate of the relationship, maintaining closeness, re-pairing and regulating negative affect and conflicts, providingemotional support, and generally enhancing the well-being of theirpartners (Erickson, 2005; Impett & Peplau, 2006; Strazdins &Broom, 2004). Women are also more likely to take an active rolein seeking change and managing disagreements (Christensen, El-deridge, Catta-Preta, Lim, & Sanagata, 2006; Denton & Burleson,2007).

These patterns suggest a complex and potentially taxing chal-lenge for women. Seeking change risks initiating or exacerbatingthe marital conflicts they otherwise wish to avoid. Seeking changein one’s partner can result in decreased relationship quality asopposed to the desired increases (Overall, Fletcher, & Simpson,2006), and strategies that are effective initially might not havebeneficial long-term effects (Overall, Fletcher, Simpson, & Sibley,2009). If women are more motivated to address marital difficultiesand maintain relationship quality, they may expend greater effortin this multifaceted task, perhaps suppressing their own negative

emotions, restraining urges to reciprocate their spouse’s negativebehaviors, and attempting to calm their spouse during potentiallydiscordant discussions. This demanding and recurring effort mayultimately be draining, reducing women’s health benefit frommarriage (Strazdins & Broom, 2004).

Recent research suggests that the capacity for such self-regulation functions analogously to a muscle; self-regulatory effortfatigues this limited resource, leaving the individual susceptible tolapses in self-control (Muraven & Baumeister, 2000). Effortfulself-regulation in social interactions reduces self-control in unre-lated contexts, and self-regulation during nonsocial tasks can im-pair subsequent social functioning by relaxing restraints on aggres-sion, disrupting self-presentation, and reducing accommodation ofone’s partner (DeWall, Baumeister, Stillman, & Gailliot, 2007;Finkel & Campbell, 2001; Finkel et al., 2006; Vohs, Baumeister,& Ciarocco, 2005). Depletion of self-regulatory resources caneven increase aggressive behavior toward intimate partners(Finkel, DeWall, Slotter, Oaten, & Foshee, 2009). If women fre-quently expend greater effort in regulating the emotional tone ofmarital interactions, they may be particularly susceptible to deple-tion of their capacity for self-regulation.

Consistent with the muscle analogy, regular practice of self-regulation can improve performance in unrelated self-regulatorytasks (Baumeister, Galliot, DeWall, & Oaten, 2006). Hence, it issomewhat unclear whether the greater efforts of women in rela-tionship regulation would ultimately reduce or strengthen theircapacity for self-regulation. The fact that women seem to enjoyless emotional and physical health benefit from marriage than menmight indicate an overall negative or depleting effect, however.

Heart Rate Variability as an Index of Self-Regulation:Capacity Versus Effort

Recent conceptual models identify the parasympathetic nervoussystem as underlying key aspects of self-regulation, including themodulation of social behavior and emotional expression (Porges,2001; Thayer & Lane, 2000). Furthermore, patterns of heart ratevariability provide an index of these parasympathetic mechanisms.Heart rate rises and falls as one breathes in and out, a patternlabeled respiratory sinus arrhythmia (RSA), which can be mea-sured as high-frequency heart rate variability (HF-HRV; Berntsonet al., 1997; Thayer, Hansen, & Johnsen, 2008). RSA and relatedmeasures of heart rate variability predict important health out-comes (Thayer & Lane, 2007) and hence can be useful in testingmechanisms linking self-regulation and health (Thayer, Hansen,Saus-Rose, & Johnsen, 2009). Each of these issues is brieflydetailed in what follows here.

This use of HF-HRV reflects the coupling of heart rate andrespiration (Thayer et al., 2008). Heart rate is largely under para-sympathetic inhibitory control, holding heart rate below its intrin-sic level. This inhibition varies across the respiratory cycle, de-creasing as people breathe in and returning as they exhale.Mechanical stretch receptors in the lungs respond during inhala-tion, briefly reducing or gating parasympathetic inhibition andresulting in increased heart rate. Parasympathetic inhibition re-turns, slowing heart rate, when stretch receptor activity decreaseswith exhalation. Hence, heart rate varies, repeatedly rising andfalling, within the range of respiration frequency (i.e., roughly 8 to25 cycles per min; 0.12 to 0.40 Hz). Variability in heart rate

104 SMITH ET AL.

corresponding to the frequency of the respiratory cycle is labeledHF-HRV, and quantification of the amount of this variabilityprovides a well-validated measure of the magnitude of RSA (Ap-pelhans & Luecken, 2006). That is, greater changes in heart rateacross the respiratory cycle indicate greater parasympathetic acti-vation.

According to polyvagal theory (Porges, 2001, 2007) and theneurovisceral integration model (Thayer & Lane, 2000, 2009), aset of brain structures and circuits called the ventral vagus complexplays a key role in parasympathetic modulation of emotion andsocial behavior (e.g., facial expressions, vocalization, etc.) andrelated physiological responses. Tonic parasympathetic inhibitionof these emotional and expressive responses (i.e., vagal tone) canbe rapidly altered, permitting flexible responding as individualsvary their engagement with the social environment. Resting levelsof HF-HRV provide an index of this tonic parasympathetic influ-ence and reflect the individual’s capacity for regulation. In con-trast, short-term increases and decreases in HF-HRV reflect appli-cation or withdrawal, respectively, of the vagal brake onsympathetic activation, indicating changes in self-regulatory ef-fort. For example, short-term decreases in HF-HRV are commonduring psychological stress, indicating the withdrawal of parasym-pathetic inhibition (Berntson, Cacioppo, & Quigley, 1994),whereas, as discussed below, efforts to regulate emotion andbehavior evoke short-term increases in HF-HRV.

Neural circuits supporting effortful control, self-regulation ofemotion and social behavior, and parasympathetic influences onthe heart are colocalized in the brain, comprising an integratedregulatory system (Porges, 2007; Thayer et al., 2009; Thayer &Lane, 2009). Anesthesia of regions of the prefrontal cortex in-volved in regulation of emotion and social behavior decreasesHF-HRV and raises heart rate as parasympathetic inhibition issuppressed (Ahern et al., 2001). These brain regions support as-pects of shifting attention, response inhibition, and selection ofalternative responses that are central in effortful control and exec-utive cognitive functions (Suchy, 2009), key cognitive underpin-nings of the modulation of emotional expression and social behav-ior (Ochsner & Gross, 2007; Posner & Rothbart, 2007; von Hippel,2007). Furthermore, measures of heart rate variability correlatepositively with performance on executive cognitive functioningtasks (Hansen, Johnsen & Thayer, 2003) and with activation ofrelated brain structures (e.g., anterior cingulate cortex) duringexecutive cognitive functioning tasks such as response inhibition(Gianaros, Van Der Veen, & Jennings, 2004; S. C. Matthews,Paulus, Simmons, Nelesen, & Dimsdale, 2004).

Consistent with these models of parasympathetic influences onself-regulation and emotional and social functioning, lower tonicor resting HF-HRV is associated with negative affect and use ofmaladaptive coping strategies (Fabes & Eisenberg, 1997; Gyurak& Ayduk, 2008), negative emotional traits such as depression andanxiety (Thayer & Brosschot, 2005), reduced regulation of nega-tive affect (Pu, Schmeichel, & Demaree, 2009), insecurity inromantic relationships (Diamond & Hicks, 2005), social isolation(Horsten et al., 1999), and antagonistic personality traits (Demaree& Everhart, 2004; Sloan et al., 1994). However, other research hasfound that stress-related decreases in HF-HRV, but not toniclevels, are associated with the quality of social relationships (Egi-zio et al., 2008). In animal models, disruption of social bondsreduces HF-HRV (Grippo, Lamb, Carter, & Porges, 2007). Asso-

ciations of these psychosocial factors with low tonic HF-HRV areimportant in light of evidence that low HF-HRV confers risk ofcardiovascular disease and earlier mortality (Thayer & Lane,2007); HF-HRV could mediate associations between psychosocialrisk factors and health outcomes.

These findings generally support the view that tonic HF-HRVreflects self-regulatory capacity (Porges, 2007; Thayer & Lane,2009). Given the role of that capacity in shaping behavior thatpromotes marital quality (e.g., modulating negative affect), tonicHF-HRV should be positively associated with marital quality.Furthermore, if self-regulatory effort can temporarily deplete thiscapacity and if women are more likely than men to exert effort inregulating the tone of marital interactions, women should be morelikely to display a decrease in resting HF-HRV following poten-tially stressful marital interactions. This pattern, in turn, couldcontribute to women’s reduced health benefit from marriage.

The research reviewed above supports the view that tonic orresting HF-HRV reflects self-regulatory capacity. Other studiessupport the view that self-regulatory effort evokes concurrentincreases in HF-HRV. Alcoholics who report good control overimpulses to drink show an increase in HF-HRV during exposure toalcohol cues, whereas those with poor control do not (Ingjaldsson,Laberg, & Thayer, 2003). Efforts to resist attractive foods increaseHF-HRV relative to resisting less attractive food (Segerstrom &Nes, 2007). Furthermore, attempts to suppress negative emotionduring social interaction increase HF-HRV (Butler, Wilhelm, &Gross, 2006), and adults with emotional self-regulation difficultiesdisplay smaller increases in HF-HRV in response to self-regulatory challenges (Austin, Rinolo, & Porges, 2007; Hughes &Stoney, 2000; Sahar, Shalev, & Porges, 2001). Given this effect ofeffortful self-regulation on concurrent HF-HRV and the fact thatwomen are more likely to engage in such efforts during stressfulmarital interactions than are men, women should be more likely todisplay temporary increases in HF-HRV during marital interac-tions that call for regulation of emotion and behavior.

The Present Study

Adaptive functioning in marriage requires self-regulation, andmarital quality has far-reaching effects on health. Hence, marriageis an important context for examining HF-HRV. As an index ofself-regulatory capacity, resting HF-HRV should be associatedwith marital quality (i.e., greater positivity and support, less neg-ativity and conflict). Furthermore, efforts to regulate emotions orexpressive behavior should evoke increases in HF-HRV duringpotentially stressful marital interactions and reductions in restingHF-HRV after such interactions, indicating depletion of the capac-ity for self-regulation.

To examine these issues, we used data from a previously re-ported study (Nealey-Moore et al., 2007) on cardiovascular reac-tivity during stressful marital interactions. In addition to traditionalmeasures of cardiovascular reactivity (i.e., changes in blood pres-sure and heart rate), the Nealey et al. (2007) study measuredHF-HRV and cardiac preejection period (PEP), an index of sym-pathetic nervous system activation (Cacioppo, Uchino, & Bern-ston, 1994). Heart rate is useful for our present focus, as it reflectsthe cardiovascular reactivity hypothesized to link psychosocial riskfactors like marital strain with subsequent cardiovascular disease(Chida & Steptoe, 2010; Schwartz et al., 2003). PEP corresponds

105MATTERS OF THE VARIABLE HEART

to the initial portion of a heartbeat, specifically the brief intervalbetween the depolarization of the heart at the beginning of acontraction and the point when blood forces open the aortic valve.PEP shortening reflects sympathetic activation that causes morerapid and forceful heart contractions (Berntson et al., 1994). In thepresent context, PEP shortening reflects the sympathetically me-diated stress response typically evoked by marital conflict (Robles& Kiecolt-Glaser, 2003).

As described in the prior report (Nealey-Moore et al., 2007),young married couples completed measures of relationship qualityand engaged in a negative, positive, or neutral initial task, in whichthey took turns describing their partner’s negative personalitytraits, positive traits, or what they knew about each other’s typicaldaily schedule, respectively. Heart rate, blood pressure, HF-HRV,and PEP were monitored during an initial baseline, the initial task,and a second baseline. All couples then discussed a relationshipissue they identified as a source of recent disagreement, whilephysiological responses were again recorded. State affect andperceptions of the spouses’ behavior were also assessed. Both thenegative initial task and the subsequent disagreement discussionevoked significant levels of cardiovascular reactivity (i.e., in-creases in heart rate and blood pressure), relative to baselines andthe neutral and positive tasks, as well as reductions in PEP indic-ative of sympathetic nervous system activation. The disagreementdiscussion, but not the negative initial task, evoked concurrentdecreases in HF-HRV indicative of parasympathetic withdrawaltypically seen during the experience of psychological stress (Bern-tson et al., 1994).

Here, we examine several issues regarding HF-HRV as an indexof self-regulatory capacity and effort that were not addressed in theprior report. Specifically, here, we report additional results regard-ing (a) the association of marital quality with resting HF-HRV; (b)the effects of the valence of the initial task on resting HF-HRV,HR, and PEP; (c) the effects on the valence of the initial task onchanges in HF-HRV, HR, and PEP during the subsequent dis-agreement discussion; and (d) mediational analyses of psycholog-ical influences on HF-HRV as an index of self-regulatory capacityand effort.

First, because tonic HF-HRV reflects self-regulatory capacityand because such regulation influences marital quality, we pre-dicted that resting HF-HRV would be positively associated withmarital quality. Second, a stressor that depletes self-regulatorycapacity should temporarily reduce resting HF-HRV. For stressorsinvolving the quality of close relationships, this effect should bemore apparent in women than men, given women’s greater in-volvement in managing relationship quality and regulating the toneof marital interactions. Hence, we predicted that the negativeinitial task would decrease resting HF-HRV from before to fol-lowing the negative initial task (i.e., from first to second baseline)more in women than men. Comparisons of these effects on restingHF-HRV with potential effects on resting PEP and resting levels ofnegative affect can help clarify whether the predicted reductions inresting HF-HRV could alternatively be seen as simply reflectingcontinuing psychological stress responses after negative interac-tions.

The negative initial task did not directly manipulate self-regulatory effort. Therefore, we examined associations of changein resting HF-HRV with changes in negative affect and percep-tions of spouse behavior during the task to determine if decreases

in regulatory capacity were mediated by emotion or social behav-ior related to such regulatory efforts. For example, husbandsexperiencing high levels of negative affect likely pose a moreimportant or difficult challenge to wives’ regulatory efforts, lead-ing to greater depletion of regulatory capacity. Hence, husbands’levels of negative affect should mediate the effects of initial taskvalence on wives’ resting HF-HRV.

Third, we examined effects of negative, neutral, or positiveinitial tasks on HF-HRV, HR, and PEP during the subsequentdisagreement discussion. Participation in the prior negative task inwhich participants took turns describing each other’s faults in-creased the potential for escalating negative emotion and behavioras the couple then discussed an ongoing marital disagreement,more so than for couples who had participated in the prior positiveor neutral task. Given the importance of regulating the tone ofpotentially discordant marital interactions for women, the negativeinitial task should particularly heighten their self-regulatory effortsduring the later disagreement discussion. Therefore, we predictedthat after the negative initial task, women more so than men woulddisplay a concurrent increase in HF-HRV during the disagreementdiscussion. This increase in HF-HRV differs substantially from thedecrease in parasympathetic activity typically seen during psycho-logical stressors (Berntson et al., 1994). We also examined nega-tive affect and ratings of spouse behavior during the disagreementdiscussion, as potential correlates of these changes in HF-HRV.Wives’ greater efforts to regulate the tone of the disagreement, forexample, could be evident in husbands’ ratings of wives as warmeror more directive during this discussion. Also, high levels ofnegative affect in their husbands could increase the importance ordifficulty of self-regulation during disagreement for wives in thenegative initial task condition.

Finally, effects of the valance of the initial task on PEP and HRresponses during the disagreement discussion, also not examinedin the prior report (Nealey-Moore et al., 2007), provide an indi-cation of sympathetically mediated stress responses and generalcardiovascular reactivity, respectively. These measures can clarifythe interpretation of changes in HF-HRV during disagreement.Specifically, if the predicted increase in wives’ HF-HRV duringthe disagreement discussion when it followed the negative initialtask reflects self-regulatory effort during a potentially stressfulmarital interaction, it should be accompanied by a reduction inPEP (i.e., increased sympathetic activation). Furthermore, changesin HR and PEP during this disagreement provide additional psy-chophysiological indications of sex differences in risks and bene-fits associated with marital interaction.

Method

Participants

Married couples (114) were recruited from the University ofUtah and the Salt Lake City community. Participants were ex-cluded if married for less than 9 months, pregnant, taking medi-cation that affected cardiovascular responses (e.g. beta blockers),or diagnosed with cardiovascular disease. Couples received $40for their participation. Most couples (52.1%) had been marriedfrom 1 to 3 years. The average age for men and women was 30.1years and 28.5 years, respectively, and most were Caucasian(88%).

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Measures

Marital quality. Prior to the laboratory session, participantscompleted the Quality of Relationship Inventory (QRI; Pierce,Sarason, & Sarason, 1997) and the Social Relationship Inventory(SRI; Campo et al., 2009). The QRI has subscales assessingperceived support from the spouse, conflict, and relationshipdepth, each of which has been found to have adequate internalconsistency (all Cronbach’s �s � .80 in the present sample),temporal stability, and convergent validity (Pierce et al., 1997).The SRI assesses relationship positivity and negativity. Previousresearch has provided evidence of adequate internal consistency(�s � .70 in the present sample), temporal stability, and constructvalidity (Campo et al., 2009). To obtain an overall measure ofmarital quality, principal components analyses were conducted onthese measures. Analysis of wives’ reports revealed one factor(eigenvalue � 3.24, 64% variance), as did analysis of husbands’reports (eigenvalue � 2.79, 55% variance); in all cases, factorloadings were as expected, with absolute values ranging from .68to .83. In both analyses, the second eigenvalue was less than .80.Composite scores were computed on the basis of unit weighting.

To identify disagreement topics, participants independentlycompleted the Couples Problem Inventory (Gottman, Markman, &Notarious, 1977), in which they rated their level of disagreementfor several common areas of marital conflict (e.g., householdchores, finances, children). Participants also completed the Centerfor Epidemiological Studies Depression Scale (Radloff, 1977).

State affect and perceptions of spouse behavior. Followingbaseline periods and after both tasks, participants completed a12-item state affect scale, based on the State-Trait PersonalityInventory (Spielberger, 1980), assessing anxiety and anger andincluding negative (e.g., anxious, irritated) and positive items (e.g.,calm, friendly). The scales have high levels of internal consistency(Cronbach’s � � .80 in the present study and others; see Nealey-Moore et al., 2007). The anger and anxiety scales were combinedto form a negative affect scale. Instances where the subscalesprovided differing findings are noted. Participants rated theirspouse’s behavior during both tasks using the Impact MessageInventory (IMI-C; Kiesler, Schmidt, & Wagner, 1997; see Nealey-Moore et al., 2007). The IMI-C assesses the two dimensions of theinterpersonal circumplex (Wiggins, 1996), affiliation (i.e., hostile,quarrelsome vs. warm, friendly) and control (i.e., dominant, direc-tive vs. submissive, passive). These scales had high levels ofinternal consistency in the present study (Cronbach’s �s � .78),and previous research has demonstrated their internal consistencyand validity (Gallo, Smith, & Kircher, 2000).

Physiological measures. Quantification of HF-HRV andPEP requires continuous recording of an electrocardiogram (ECG)signal, which also provides heart rate. PEP also requires measure-ment of moment-to-moment changes in blood volume within theheart, corresponding to beat-to-beat changes in electrical imped-ance across the chest region. As noted above, PEP is the period oftime between the initiation of a contraction of the heart, capturedby the ECG signal, and the point when blood begins to flow out ofthe left ventricle, captured by the changing impedance signal.Decreases in PEP (i.e., faster heart contraction) reflect increasedsympathetic activity (Cacioppo et al., 1994). ECG, basal thoracicimpedance (Zo), and the first derivative of the impedance signal(dZ/dt) were measured continuously using Minnesota Impedance

Cardiographs (Model 304B, Surcom; Minneapolis, MN). Fourband electrodes were placed consistent with guidelines (Sherwoodet al., 1990). Heart rate and PEP values were calculated as aver-ages for each 1-min interval of all experimental periods. HF-HRVwas calculated on the basis of the digitized interbeat intervals(IBIs) from the ECG. Epochs were checked and edited for artifactsusing the algorithm of Berntson, Quigley, Jang, and Boysen(1990). A heart period time series was created from the IBIs usingthe weighted beat algorithm described by Berntson et al. (1994). Alinear polynomial was fit to, and subtracted from, the heart periodtime series (Litvack, Oberlander, Carney, & Saul, 1995), providinga high pass filter removing very large ultralow-frequency trendsfrom the input signal. The heart period time series was thenbandpass-filtered from 0.12 to 0.40 Hz (Neuvo, Cheng-Yu, &Mitra, 1984). HF-HRV was calculated for each minute of allperiods as the natural log of the area under the heart period powerspectrum within the corner frequencies of the bandpass filter(Litvack et al., 1995). Further details can be found in Nealey-Moore et al. (2007). The number of couples for specific analysesvaried somewhat due to missing data from poor-quality impedancecardiography recordings.

Procedure

Interested couples were contacted by telephone and inter-viewed for eligibility. Qualified couples received a packet ofquestionnaires (see above), with instructions to complete themindependently before the scheduled laboratory session. Thetime line for the experimental session, described below, ispresented in Figure 1.

Baseline period. Participants were seated side by side (2 ftapart) in a sound-attenuated chamber, so that they were able tolook at one another easily. Instructions were played over a speaker,describing the study as examining physiological effects of speechand emotion. The experimenter entered the room to answer ques-tions and attach sensors. A curtain was then drawn between theparticipants, and the experimenter left to begin the baseline period.An audiotape led participants through a 10-min baseline in whichthey viewed a pair of outdoor scenes for 1 min and then rated thatpair before moving on to the next. At the end of baseline, partic-ipants completed a measure of state affect, indicating how they feltduring the baseline. The first assessment of resting HR, HF-HRV,and PEP was calculated as the average over the final 3 min of thebaseline.

Initial task. Via audiotaped instructions, participants weretold to alternate periods of speaking and listening and that theirdiscussions would be monitored from the adjacent room. Partici-pants were told to speak for the time allotted and not to speak outof turn. Participants could respond to their spouse’s comments, butonly after they provided the requested information. Those in thepositive condition were provided with 60 positive adjectives (e.g.,responsible, affectionate) and asked to select three that describedtheir spouse. During six 1-min periods, they alternated listening tothe spouse and describing how the spouse displayed each selectedattribute. In the negative condition, participants were providedwith 60 negative adjectives (e.g., irresponsible, unaffectionate) andwere asked to select three that characterized their spouse. In aneutral condition, participants were asked to discuss their partner’stypical daily schedule, using the same task structure. This alter-

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nating task structure provides control over speech artifacts that canalter physiological responses, while still permitting couple inter-action. Participants prepared silently for 3 min. The experimenterthen drew back the curtain and indicated who would speak first.Speaking order was counterbalanced. The experimenter exited,and recorded instructions prompted participants for the speakingand listening periods. After the task, participants completed asecond affect scale, referring to how they felt during the task, andthe IMI-C, to describe their spouse’s task behavior.

Disagreement discussion. Participants underwent a second10-min baseline, again separated from view; the final 3 min wereaveraged to obtain the second resting level of HR, HF-HRV, andPEP. All couples then discussed a topic (e.g., finances, in-laws)from the Couples Problem Inventory. Among issues rated as atleast moderately problematic for both members, the highest com-bined rating was selected. Participants prepared for 3 min and thendiscussed the topic in six 1-min segments, alternating listening andspeaking (order was counterbalanced). They then discussed thetopic for 4 min without instructions to take turns. Physiologicalmeasures were recorded continuously, and 1-min values for HR,HF-HRV, and PEP were averaged within preparation, listening,speaking, and unstructured discussion periods. Participants thencompleted a final set of state affect scales and ratings of spousebehavior during the disagreement.

Results

Associations of Regulatory Capacity (Resting HF-HRV)With Relationship Quality

Means (and standard deviations) for the marital quality mea-sures, resting physiological measures, and other primary variablesare presented in Table 1. We predicted that self-regulatory capacityas reflected in initial resting values (i.e., first baseline) of HF-HRVwould be positively associated with marital quality. We tested thisprediction through correlations and regressions. Wives’ initialbaseline HF-HRV was associated with their own composite reportsof marital quality, r(109) � .20, p � .04, but not with theirhusbands’ reports, r(109) � .10. Of the individual scales, wives’resting HF-HRV was associated with their reports of relationshipdepth and positivity, both r(109) � .20, p � .05. Husbands’ initial

resting HF-HRV was associated both with their own compositereports of marital quality, r(109) � .25, p � .01, and with theirwives’ reports, r(109) � .27, p � .01. Of the individual scales,husbands’ initial resting HF-HRV was associated with their ownreports of marital conflict, r(109) � �.23, p � .05; negativity,r(109) � �.30, p � .01; and positivity, r(109) � .21, p � .05, andtheir wives’ reports of depth, r(109) � .26, p � .01; positivity,r(109) � .26, p � .01; and conflict, r(109) � �.27, p � .01.

Husbands’ and wives’ resting HF-HRV levels were correlated,r(109) � .30, p � .01. To examine potentially overlapping asso-ciations of husbands’ and wives’ resting HF-HRV with wives’reports of relationship quality, we examined both predictors in asimultaneous regression, R2 � .088, F(2, 106) � 5.14, p � .007.Husbands’ resting HF-HRV was independently related to wives’reported marital quality, � � .23, t(106) � 2.40, p � .018, but

Initial Task Positive, Neutral, or Negative (3 min preparation) (6 1-min structured turns)

Disagreement Discussion (3 min preparation) (6 min turn taking) (4 min unstructured talk)

Baseline 1 Task 1 Baseline 2 Task 2

Resting 1 (3 min) (HR, HF-HRV, PEP)

Resting 2 (3 min) (HR, HF-HRV, PEP)

State Affect 1 State Affect 2 Appraisals of Spouse Behavior

State Affect 3

HR, HF-HRV, PEP

State Affect 4 Appraisals of Spouse Behavior

10 min 10 min

HR, HF-HRV, PEP

Figure 1. Time line of procedures for initial task and disagreement discussion. HF-HRV � high-frequencyheart rate variability; HR � heart rate; PEP � preejection period.

Table 1Means for Wives’ and Husbands’ Relationship QualityMeasures, Affect Reports and Behavioral Ratings During theInitial Task, and Baseline Physiological Measures

Measure

Wives Husbands

M SD M SD

QRI support 25.42 3.19 25.41 2.42QRI conflict 33.29 2.30 33.37 2.42QRI depth 22.55 2.38 22.78 2.11SRI positive 5.03 0.84 5.16 0.84SRI negative 2.27 0.99 2.17 1.01Anger change 0.08 2.96 0.04 2.65Anxiety change 1.27 3.37 1.21 3.27Spouse affiliation 3.86 2.10 3.99 1.87Spouse control �0.61 1.04 �0.58 1.01Baseline 1 HF-HRV 6.20 1.24 5.44 1.22Baseline 2 HF-HRV 6.18 1.18 5.42 1.24Baseline 1 PEP 130.3 20.59 128.08 23.29Baseline 2 PEP 130.6 19.73 128.58 25.02Baseline 1 HR 72.59 9.63 73.79 11.78Baseline 2 HR 72.20 9.82 73.07 11.57

Note. QRI � Quality of Relationship Inventory; SRI � Social Relation-ship Inventory; HF-HRV � high-frequency heart rate variability; PEP �preejection period; HR � heart rate.

108 SMITH ET AL.

wives’ resting HF-HRV was not, � � .13, t(106) � 1.30, p � .20.Hence, as predicted, resting levels of HF-HRV were associatedwith higher reports of marital quality, presumably reflecting thepositive role of self-regulatory capacity. The association betweenhusbands’ resting HF-HRV and their wives’ reports of maritalquality could indicate that husbands with better regulatory capacitypose less of a burden to wives’ efforts to promote relationshipquality. Consistent with this view, husbands with higher restingHF-HRV were rated by their wives as warmer during the initialtask, while controlling the effects of the valence of the initial taskcondition (� � .21, p � .018). Wives’ resting HF-HRV tended tobe associated with husbands’ ratings of wives’ warmth, controllinginitial task valence, but this association was not significant (� �.15, p � .064).

Overview of Initial Task Manipulation Checks andPhysiological Responses

As reported elsewhere (Nealey-Moore et al., 2007), the effec-tiveness of the manipulation of initial task valence was tested in 3(initial task conditions: positive, neutral, negative) � 2 (spouse:husband, wife) mixed analyses of variance (ANOVAs) on partic-ipants’ ratings of spouses’ affiliation and control during the task, aswell as their self-reported changes in state affect, treating spouse asa repeated factor to control dependency in husbands’ and wives’responses (Kenny, 1995). As expected, compared to the neutraltask, those in the negative initial task rated spouses as displayingsignificantly less affiliation (i.e., more hostility) and more controland reported a significantly larger increase in negative affect.Compared to the neutral task, those in the positive task rated theirspouses as displaying significantly more affiliation (i.e., warmth)and less control. Participants displayed a significantly larger in-crease in heart rate and blood pressure and a larger decrease in PEP(i.e., greater sympathetic response) during the negative task than inthe other conditions (see Nealey-Moore et al., 2007). Importantly,conditions did not differ in changes in HF-HRV during the initialtask. There were no sex differences on any of these measures, andno Sex � Conditions interactions approached significance. Hence,the tone of the initial task was manipulated as intended, withexpected effects on cardiovascular reactivity.

Effects of Initial Task Valence on Subsequent RestingHF-HRV, PEP, and Heart Rate

To test the prediction that the negative initial task would depleteself-regulatory capacity (i.e., reduce resting HF-HRV; see Figure1) for wives but not for husbands, we conducted a 3 (initial taskconditions: positive, neutral, negative) � 2 (spouse: husband,wife) � 2 (periods: Baseline 1 vs. Baseline 2) mixed ANOVA,treating spouse and periods as repeated factors. Similar ANOVAswere used for resting heart rate and PEP. Significant effects wereexplicated with mean comparisons (Bernhardson, 1975).

This mixed ANOVA of resting HF-HRV indicated a spousemain effect, F(1, 105) � 34.3, p � .001, �2 � .24; women hadhigher resting values than men (6.19 vs. 5.41; SEs � .12, .11). Theexpected three-way interaction was also significant, F(2, 105) �3.63, p � .03, �2 � .065. To explicate this effect, Conditions �Periods mixed ANOVAs were conducted for men and womenseparately. For men, this interaction was not significant, F(2,

106) � 1.40, p � .25, �2 � .026, but as predicted, it wassignificant for women, F(2, 106) � 5.98, p � .003, �2 � .10.Following the negative initial task, women’s resting HF-HRVdecreased significantly, t(106) � 2.85, p � .05; increased some-what following the positive task, t(106) � 1.80, p � .08; and didnot change following the neutral task.

Initial resting HF-HRV levels were associated with the magni-tude of change in resting HF-HRV (i.e., Baseline 2 � Baseline 1)for both women, r(109) � �.33, p � .001, and men, r(109) ��.18, p � .06. To control any contribution of initial levels toconditions effects on changes in resting HF-HRV, we conductedanalyses of covariance (ANCOVAs) of change in resting HF-HRV, controlling initial levels. Among men, as expected, theconditions effect was again not significant, F(2, 106) � 1.84, p �.16, �2 � .034, but this predicted effect was significant for women,F(2, 106) � 7.32, p � .001, �2 � .12. As depicted in Figure 2,women displayed a significant drop in resting HF-HRV followingthe negative initial task, no change after the neutral task, and asmall but significant increase after the positive task. The meandecrease for the negative task group differed significantly from theneutral and positive groups. Because ANCOVA of change scorescontrolling initial levels sometimes produces misleading results(Jamieson, 2004), it is important to note that ANOVA of unad-justed change scores produced essentially identical results.

Conditions � Spouse � Periods ANOVAs of baseline PEP andheart rate revealed no effects approaching significance, nor didConditions � Spouse ANCOVAs of change, controlling initiallevels. Hence, the decrease in resting HF-HRV in wives followingthe negative initial task was not accompanied by increased sym-pathetic activity indicative of stress (i.e., PEP shortening). Con-sistent with this view, Conditions � Periods ANOVA of wives’baseline negative affect indicated only that negative affect de-creased generally from the initial to the second baseline, F(1,115) � 8.95, p � .003, �2 � .072. The Conditions � Periodsinteraction did not approach significance, F(2, 115) � 1.88, p �.16, �2 � .032. There was a tendency for wives to report a largerdecrease in negative affect following the positive initial task (M ��2.13, SE � .60) than after the neutral (M � �0.69, SE � .58) ornegative initial task (M � �0.74, SE � .59), but there was clearlyno evidence that negative initial task evoked a change in negativeaffect that could account for the effect of the negative initial taskon wives’ resting HF-HRV.

-0.4

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0

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Posi�ve Neutral Nega�ve

Valence of Ini�al Task

Chan

ge in

Res

�ng

HF-

HRV

(log

unit

s)

Wives Husbands

Figure 2. Mean changes (and standard errors) in resting HF-HRV fol-lowing positive, neutral, or negative initial task. HF-HRV � high-frequency heart rate variability.

109MATTERS OF THE VARIABLE HEART

Mediators of Effect of Initial Task Valence onResting HF-HRV

As noted above, the negative initial task did not directly manip-ulate self-regulation, and women’s HF-HRV change during theinitial task did not differ across the positive, neutral, or negativeconditions. This raises a question regarding the extent to whichdecreases in women’s resting HF-HRV were due to self-regulatoryeffort during the negative initial task, as such effort should haveevoked an increase in HF-HRV during that task (Butler et al.,2006; Segerstrom & Nes, 2007). To address this issue, we testedassociations of psychological responses to the initial task thatshould be related to self-regulatory effort with changes in wives’resting HF-HRV. Specifically, if women’s effort was greater asthey managed their own or their spouses’ affect during the nega-tive initial task, changes in women’s resting HF-HRV should bemediated by (a) their own or their spouses’ reports of negativeaffect during the initial task, (b) their ratings of their husbands’behavior during the task, and/or (c) husbands’ ratings of theirwives’ behavior. Multiple regressions (cf. R. M. Baron & Kenny,1986) were used in these mediation analyses.

As described above, the initial task condition had significanteffects on each of these psychological responses (Nealey-Moore etal., 2007). As presented in Table 2, all but one of these responsesto the initial task were significantly related to wives’ change inresting HF-HRV. When controlling valence of the initial task,husbands’ reports of negative affect during this task and husbands’ratings of wives’ affiliation and control during the task weresignificantly associated with change in wives’ resting HF-HRV.

In regression analyses of women’s change in resting HF-HRV(while controlling initial resting HF-HRV levels), the conditionsfactor (i.e., Contrast 1 � positive vs. neutral initial task, Contrast2 � negative vs. neutral initial task) was significantly related tochange in resting HF-HRV, R2 � .102, F(2, 105) � 6.72, p �.001; the positive task increased resting HF-HRV (� � .27,p � .017), and the negative task decreased resting HF-HRV (� ��.37, p � .001). When entered next, the block of six psycholog-ical responses to the initial task accounted for a significant amountof additional variance in women’s resting HF-HRV change, R2 �.16, F(6, 99) � 4.13, p � .001. Within this block, husbands’reported increase in negative affect (� � �.30, p � .003) and

husbands’ ratings of wives’ control during the initial task (� ��.23, p � .021) were independently related to wives’ change inresting HF-HRV. That is, wives displayed a larger decrease inresting HF-HRV following the initial task if their husbands re-ported a larger increase in negative affect during that task and iftheir husbands rated the wives’ task behavior as more controllingor directive. Importantly, with these factors controlled, neither thepositive versus neutral task contrast (� � .15, p � .12) or thenegative versus neutral task contrast (� � �.19, p � .064)remained significant, suggesting that these psychological re-sponses mediated both wives’ decrease in resting HF-HRV fol-lowing the initial negative task and the increase following thepositive task. These results are summarized in Figure 3.

Sobel tests (MacKinnon, Lockwood, Huffman, West, & Sheets,2002) of these meditational paths indicated that both husbands’negative affect and their ratings of wives as more controlling ordirective were significant mediators of effects of the negativeinitial task on decreases in wives’ resting HF-HRV (test values �2.43, p � .015, and 2.24, p � .025, respectively). Husbands’reports of negative affect were also a significant mediator of theeffect of the positive task on wives’ increases in HF-HRV (testvalue � 2.06, p � .039), but husbands’ ratings of wives as moredirective only approached significance (test value � 1.94, p �.052).

Husbands’ negative affective responses to the initial task wereclearly apparent to their wives, as husbands who reported largerincreases in negative affect were rated by their wives as lessfriendly, � � �.34, t(117) � 3.42, p � .001, controlling theeffects of task valence. Yet, whereas husbands’ negative affect wasindependently related to wives’ change in resting HF-HRV, wives’ratings of the husbands’ behavior were not.

In exploratory analyses, when controlling initial resting levels ofHF-HRV and task condition, husbands’ depressive symptoms wereassociated with a larger decrease in wives’ resting HF-HRV, � ��.19, t(116) � 2.00, p � .05. This association was also significantamong wives in the initial negative task, � � �.34, t(33) � 2.16,p � .04. To the extent that interacting with a husband experiencingdepressive symptoms requires greater self-regulatory effort (espe-cially when trading criticisms), these ancillary results support the

Table 2Associations of Emotional Response and Ratings of Spouse Behavior During the Initial TaskWith Wives’ Post–Pre Change in Resting High-Frequency Heart Rate Variability

Predictor Tested individuallyTested individually

controlling conditionTested simultaneouslycontrolling condition

Wives’ responsesReported negative affect �.24�� �.16 �.01Rating of husbands’ affiliation .26�� .15 �.01Rating of husbands’ control �.12 �.05 �.01

Husbands’ responsesReported negative affect �.42�� �.36�� �.30��

Rating of wives’ affiliation .33�� .24� .02Rating of wives’ control �.37�� �.31�� �.23�

Note. Values are standardized coefficients, controlling initial resting baseline high-frequency heart ratevariability.�p � .05, two-tailed. �� p � .01, two-tailed.

110 SMITH ET AL.

view that wives’ decrease in resting HF-HRV reflects self-regulatory depletion.

Hence, although self-regulation was not directly manipulatedduring the initial task and although the negative initial task did notevoke a concurrent increase in HF-HRV reflecting self-regulatoryeffort, these additional analyses support the interpretation that thedecrease in wives’ resting HF-HRV after the negative initial taskreflected depletion of self-regulatory capacity. Specifically, psy-chological factors that could increase the importance or difficultyof self-regulation for wives during the initial task (i.e., higherlevels of husbands’ negative affect during the task) and indicationsof such effortful regulation (i.e., more directive behavior displayedby the wives during the initial task) were significant mediators ofthe effect of the negative initial task on wives’ resting HF-HRV.The unexpected increase in wives’ resting HF-HRV after the positiveinitial task was significantly mediated by husbands’ reports of nega-tive affect during that task. This might indicate a restorative effect(A. W. Smith & Baum, 2003) of positive interactions with husbandswho experience less tension and irritability—or greater calm andwarmth—on women’s self-regulatory capacity, but this interpretationis clearly speculative.

Effects of Initial Task Valence on Responses to theSubsequent Disagreement Discussion

HF-HRV. We predicted that the negative initial task wouldincrease self-regulatory effort during the subsequent disagreementdiscussion, as reflected in increases in HF-HRV during the dis-cussion, more so for wives than husbands. To test this effect,change scores were calculated by subtracting the baseline valuesimmediately preceding the disagreement (i.e., second baseline)from average preparation, listening, speaking, and unstructureddiscussion values (Llabre, Spitzer, Saab, Ironson, & Schneider-man, 1991). These change scores were subjected to a 3 (initial taskconditions) � 2 (spouse) � 4 (periods: preparation, listening,speaking, unstructured discussion) mixed ANOVA, with adjust-ment for the periods factor (Greenhouse & Geisser, 1959). Be-cause initial levels (i.e., second baseline) of HF-HRV were againcorrelated with change scores, this analysis of change in HF-HRVduring disagreement was followed with ANCOVA of changescores controlling initial levels (i.e., second baseline levels), toeliminate the possibility that initial levels of HF-HRV contributed

to observed effects during the disagreement discussion. Again,because this use of ANCOVA can produce misleading results(Jamieson, 2004), results were also compared to those obtainedwith analysis of simple changes scores (Llabre et al., 1991).

The 3 (conditions) � 2 (spouse) � 4 (periods: preparation,speaking, listening, unstructured interaction) mixed ANOVA ofchanges in HF-HRV during disagreement revealed the predictedSex � Conditions interaction, F(2, 103) � 7.88, p � .001, �2 �.133. As a follow-up analysis considering men and women sepa-rately, in a 3 (conditions) � 4 (periods) mixed ANCOVA control-ling second baseline HF-HRV levels, neither the conditions maineffect nor the Conditions � Periods interaction approached signif-icance for men, who showed little or no change in HF-HRV duringthe disagreement discussion.

In contrast, for women, the predicted conditions main effect wassignificant, F(2, 105) � 10.62, p � .001, �2 � .168. As depictedin Figure 4 (top panel), following the negative initial task, womendisplayed a significant increase in HF-HRV over baseline levelsduring the disagreement discussion, whereas they displayed sig-nificant decreases when it followed the positive or neutral tasks.Each of these changes differed from zero, and the change in thenegative initial task condition was significantly different fromthe neutral and positive conditions, both t(105) � 3.95, p � .001;the latter two conditions did not differ. An ANOVA of unadjustedHF-HRV change scores produced virtually identical results.Hence, women displayed significant parasympathetic withdrawaltypical of psychological stress (Berntson et al., 1994) during thedisagreement discussion, except when disagreement followed thenegative initial task. In that condition, they displayed a significantincrease in HF-HRV, a response previously associated with self-regulatory effort during social interaction (Butler et al., 2006).

Respiration and speech can affect HF-HRV and its validity as anindex of RSA (Berntson et al., 1997). Therefore, we also tested theseeffects within each of the four disagreement discussion periods sep-arately. In this way, we evaluated the consistency of the predictedeffect across periods or activities that varied widely in the presence ofpotential speech artifacts (e.g., preparation, listening vs. speaking,unstructured discussion). As presented in Table 3, the predicted initialtask condition effect on women’s HF-HRV change during disagree-ment was significant across all four periods, suggesting that this effectdoes not covary closely with various speech artifacts.

Valence of Initial Task

a. Positive (vs. Neutral) b. Negative (vs. Neutral)

Husbands’ Change in Negative Affect

during Initial Task

Husbands’ Rating of Wives’ Controlling

Behavior during Initial Task

Change in Wives’ Resting HF-HRV

a. -.22*

b. .44**

a. -.28**

b. .32**

a. .27** (.15)

b. -.37** (-.19)

-.41** (-.30**)

-.36** (-.23*)

Figure 3. Summary of mediational analyses of change in wives’ resting HF-HRV. All values are standardizedcoefficients controlling initial resting level of HF-HRV. Values in parentheses reflect control of all other effectsin the model described in the meditational analysis (see text). HF-HRV � high-frequency heart rate variability.� p � .05. �� p � .01.

111MATTERS OF THE VARIABLE HEART

PEP. To test effects of initial task valence on sympatheticstress responses during disagreement, we conducted a similar 3(conditions) � 2 (sex) � 4 (periods: preparation, speaking, listen-ing, unstructured interaction) mixed ANOVA on PEP changes.The Sex � Conditions interaction approached significance, F(2,95) � 2.70, p � .072, �2 � .054. When tested separately forwives, the conditions main effect was not significant, F(2, 105) �0.96, p � .39, �2 � .018; wives displayed significant PEP short-ening (i.e., greater sympathetic activity) during disagreement sim-ilarly across initial task conditions. The conditions main effect wassignificant for husbands, however, F(2, 97) � 3.91, p � .023,�2 � .075. As displayed in Figure 4 (bottom panel), following thepositive initial task, husbands displayed little or no decrease inPEP during the disagreement discussion. In contrast, they dis-played significant—and significantly greater—sympathetic activa-tion when the disagreement discussion followed a neutral or neg-

ative initial task. Control of baseline values in ANCOVA did notalter these effects.

Heart rate. To examine a conventional measure of cardio-vascular reactivity during the disagreement discussion, we con-ducted a similar 3 (conditions) � 2 (sex) � 4 (periods: preparation,speaking, listening, unstructured interaction) mixed ANOVA onheart rate changes. The three-way Conditions � Sex � Activityinteraction was significant, F(6, 309) � 2.28, ε � .857, p � .036,�2 � .042. When tested separately for men and women, theConditions � Activity interaction was not significant for wives butwas significant for husbands, F(6, 318) � 4.48, ε � .847, p �.001, �2 � .079. In follow-up mean comparisons within eachperiod separately, husbands in the positive initial task conditiondisplayed less heart rate reactivity during the speaking and un-structured disagreement discussion periods (speaking change �1.87 beats per minute [bpm], SE � .87; unstructured interaction �0.49 bpm, SE � .72) than did husbands in the negative (speakingchange � 4.83 bpm, SE � .86; unstructured interaction � 2.37bpm; SE � .71) or neutral (speaking change � 3.32 bpm, SE �.87; unstructured interaction � 2.17 bpm; SE � .72) initial taskconditions. Control of initial levels via ANCOVA did not alterthese effects.

Affective and behavioral responses during the disagreementdiscussion. To evaluate possible psychological correlates of theincreases in HF-HRV presumed to reflect self-regulatory effortduring disagreement, we conducted similar 3 (conditions) � 2(sex) mixed ANOVAs. For negative affect, only the sex maineffect was significant, F(1, 113) � 8.13, p � .005, �2 � .067; bothmen and women reported a significant increase in negative affect,but it was larger for women (3.76, SE � .57) than men (2.15, SE �.59). The ANOVA of spouse ratings of control revealed no effects(all F values � 1.30).

The parallel ANOVA of ratings of spouse affiliation revealed aConditions � Sex interaction, F(2, 116) � 4.79, p � .01, �2 �.076. As depicted in Figure 5, wives’ ratings of their husbands’warmth versus hostility during disagreement did not differ acrossthe three initial task conditions. Among husbands, compared tothose in the neutral initial condition, those in the negative condi-tion rated their wives as warmer and/or less hostile during dis-agreement, t(116) � 1.95, p � 05. Husbands’ perceptions of theirwives as warmer during disagreement when it followed the neg-ative task could reflect wives’ increased efforts to modulate thetone of the disagreement, perhaps accounting for wives’ increasedHF-HRV. However, husbands’ ratings of wives’ affiliation were

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Wives Husbands

Figure 4. Mean change (and standard errors) in HF-HRV (top panel) andPEP (bottom panel) during disagreement discussion, following positive,neutral, or negative initial task. HF-HRV � high-frequency heart ratevariability; PEP � preejection period.

Table 3Effects of Initial Task Valence on Women’s Change in High-Frequency Heart Rate VariabilityDuring Each Period of the Disagreement Discussion

Period

Initial task condition

F(2, 106) �2Positive Neutral Negative

Preparation �.35a (.099) �.38a (.100) �.05b (.099) 3.35� .059Speaking �.09a (.111) �.18a (.112) .36b (.110) 6.89�� .114Listening �.22a (.099) �.17a (.099) .36b (.098) 10.65�� .166Unstructured �.10a (.097) �.09a (.096) .30b (.094) 5.74�� .098

Note. Within periods, means with different subscripts differ at p � .05. Standard errors are in parentheses.�p � .05. �� p � .01.

112 SMITH ET AL.

not related to wives’ HF-HRV response during disagreement, andstatistical control of these ratings did not reduce the effect of theinitial task on wives’ HF-HRV response to disagreement.

However, additional exploratory analyses did support the inter-pretation that wives’ increase in HF-HRV during the disagreementdiscussion when it followed the negative initial task reflectedefforts to regulate the tone of that discussion. Within the negativeand neutral initial task conditions, we regressed wives’ change inHF-HRV during disagreement on their baseline HF-HRV levels, acontrast comparing the neutral versus negative initial task condi-tions; husbands’ change in state anger (centered) during the dis-agreement discussion; and the interaction of initial task conditionand husbands’ anger. The Conditions � Husbands’ Anger inter-action was significant, � � .22, t(68) � 2.65, p � .01. Largerincreases in husbands’ anger were associated with larger decreasesin wives’ HF-HRV during the discussion when it followed theneutral initial task, r(33) � �.34, suggesting that a greater with-drawal of wives’ parasympathetic activity accompanied the stressassociated with husbands’ anger. In contrast, after the negativeinitial task, the increase in husbands’ anger was associated with alarger increase in wives’ HF-HRV, r(34) � .28.This pattern didnot occur for husbands’ anxiety. Furthermore, husbands’ change inanger was related to wives’ ratings of husbands’ affiliation,r(80) � �.38, p � .001, whereas husbands’ anxiety was not,r(80) � �.14, p � .22. Hence, greater arousal of husbands’ angerduring disagreement was associated with evidence of increasedself-regulatory effort in wives when the disagreement followed thenegative initial task, but it was associated with parasympatheticwithdrawal after the neutral task.

Discussion

Recent models of self-regulation of emotion and social behavior(Porges, 2001; Thayer & Lane, 2000, 2009) suggest that restinglevels of HF-HRV provide an index of the capacity for regulationand that self-regulatory effort evokes concurrent increases in thisindex of parasympathetic activity. In the present study, restinglevels of HF-HRV were related to marital quality, and the manip-ulated tone of marital interactions altered women’s resting andreactive HF-HRV in ways that support these conceptual models.These results extend support for those models of self-regulation tothe context of close relationships in several important ways and

suggest a novel mechanism that could contribute to women’ssmaller health benefit from marriage.

As predicted, resting HF-HRV was positively associated withmarital quality, supporting the view that tonic HF-HRV reflects aself-regulatory resource that facilitates relationship functioning(Diamond & Hicks, 2005). Interestingly, husbands’ resting HF-HRV was a more consistent correlate of their own and their wives’marital quality than was wives’ HF-HRV. This could indicate thathusbands with better capacity for self-regulation pose less of achallenge to wives’ efforts to maintain relationship quality. Sup-porting this view, husbands with higher resting HF-HRV wererated by their wives as warmer during the initial task, whilecontrolling condition. The potential importance of these associa-tions is suggested by longitudinal results in which good impulsecontrol among husbands, but not wives, predicted favorable mar-ital outcomes (Kelly & Conley, 1987). Also, husbands’ and wives’resting HF-HRV was significantly associated, suggesting that cou-ples, as well as individuals, vary in this self-regulatory resource.

Also as predicted, the negative initial task (i.e., discussing eachother’s faults) decreased resting HF-HRV among women, but notmen, suggesting that stressful marital interactions can temporarilyreduce women’s self-regulatory capacity. Challenging the inter-pretation that this decrease was due to expenditure of self-regulatory effort, women did not display increased HF-HRV dur-ing the negative initial task. However, wives’ decrease in restingHF-HRV after the negative initial task was mediated by husbands’greater negative affect and husbands’ perceptions of their wives ascontrolling and directive during that task. Hence, women whodisplayed a larger decrease in resting HF-HRV after the negativetask appear to have (a) faced a greater challenge posed by theirhusbands’ negative affect and (b) engaged in more directive effortsto manage it. It is also possible that husbands who perceived theirwives as directive and controlling posed a more difficult challengefor wives in regulating the tone of the interaction.

The positive initial task produced a small but significant in-crease in women’s resting HF-HRV, perhaps indicating that pos-itive marital experiences can have salubrious effects by tempo-rarily enhancing women’s self-regulatory capacity. Thisunexpected result was mediated by husbands’ reports of negativeaffect during the initial task, perhaps indicating that positive mar-ital interactions that reduce their husbands’ levels of tension andirritability—or increase their subjective relaxation and warmth—increase women’s self-regulatory regulatory capacity. As such,positive marital interactions could have a restorative effect (A. W.Smith & Baum, 2003) on women’s self-regulatory capacity. Thisresult should be interpreted with caution, given that it was notpredicted and may reflect other mechanisms. It is important tonote, however, that the effects of the initial task on increases anddecreases in wives’ resting HF-HRV are unlikely to reflect thesimple valence of emotional stimuli, as such linear valence effectson HF-HRV have typically not been evident in prior studies ofadults (Frazier, Strauss, & Steinhauer, 2004).

Women who engaged in the negative initial task displayed asignificant increase in HF-HRV over baseline during a later dis-cussion of an ongoing marital disagreement, whereas women whoengaged in a neutral or positive initial task displayed decreasedparasympathetic activity, a typical response to psychological stres-sors. This pattern is consistent with the hypothesis that the negativeinitial task increased the salience of maintaining marital quality

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Figure 5. Mean ratings (and standard errors) of spouse affiliation duringdisagreement discussion, following positive, neutral, or negative initialtask.

113MATTERS OF THE VARIABLE HEART

and prompted greater self-regulatory effort for women during thedisagreement discussion. This increase in HF-HRV during dis-agreement was not due to differences in baseline levels of HF-HRV, and it was observed while women actively interacted withtheir husbands (i.e., unstructured interaction period), spoke to theirhusbands, listened to their husbands, and silently prepared for thedisagreement discussion, thereby reducing the likelihood that theeffects were due to speech artifacts.

Consistent with the interpretation that this increase in HF-HRVwas due to women’s efforts to maintain relationship quality, hus-bands rated their wives’ as warmer or less hostile during thedisagreement when it followed the negative initial task than whenit followed a neutral task. However, mediational analyses usinghusbands’ ratings of wives’ affiliation did not support this inter-pretation. Yet analyses of husbands’ anger during disagreementprovided indirect support. When the disagreement followed theneutral initial task, husbands’ reports of anger were associated witha larger decrease in wives’ HF-HRV, likely indicating parasym-pathetic withdrawal during stress (Berntson et al., 1994). In con-trast, when disagreement followed the negative initial task, hus-bands’ reports of increased anger were associated with increases inwives’ HF-HRV, perhaps indicating that wives were exertinggreater effort to manage their husbands’ anger.

The increase in wives’ HF-HRV during disagreement when itfollowed the negative initial task was accompanied by a significantdecrease in PEP. Hence, after the negative task, disagreementevoked coactivation of sympathetic and parasympathetic responsesin women, presumably reflecting the simultaneous occurrence ofpsychological stress and self-regulatory effort. In the other condi-tions, decreases in wives’ PEP during disagreement were accom-panied by decreases in HF-HRV, suggesting the simultaneoussympathetic activation and parasympathetic withdrawal typical ofpsychological stress (Berntson et al., 1994; Thayer et al., 2009).Brain-imaging research suggests that effortful suppression of neg-ative affect evokes increased activation both in prefrontal cortexareas related to emotion regulation and in the amygdala, usuallyindicative of negative affect (Goldin, McRae, Ramel, & Gross,2008), paralleling the coactivation of women’s sympathetic andparasympathetic systems when disagreement followed the nega-tive task.

Overall, these results are consistent with the view that restinglevels of HF-HRV reflect self-regulatory capacity (Porges, 2001;Thayer & Lane, 2000), whereas increases in HF-HRV duringsocial interaction can reflect self-regulatory effort (Butler et al.,2006). By examining the context of a primary close relationship,these findings represent an important extension of the evidencethat HF-HRV reflects self-regulation.

The results also suggest an extension of models of mechanismslinking the quality of close relationships and health (Kiecolt-Glaser & Newton, 2001). Prevailing models identify responsesmediated by the sympathetic nervous system and hypothalamic–pituitary–adrenocortical system as key psychophysiological links(Kiecolt-Glaser et al., 2005; Robles & Kiecolt-Glaser, 2003) andsuggest that women’s more pronounced responses to marital con-flict might contribute to their smaller health benefit from marriage(Kiecolt-Glaser & Newton, 2001). The present results suggest thata greater effect of negative marital interactions on women’s HF-HRV might also contribute to this reduced benefit. That is, inaddition to greater reactivity to marital stressors, women might

also be susceptible to adverse consequences of more frequent,sustained, and perhaps ultimately taxing self-regulation directedtoward maintaining relationship quality. Such efforts could, overtime, result in decreased heart rate variability and related depletionof self-regulatory capacity, especially if these efforts were difficultor limited in their success. To the extent that women’s stressresponses are better characterized as tending and befriending, asopposed to fight or flight (Taylor et al., 2000), parasympatheticeffects of effortful tending are potentially important additionallinks to health.

Low heart rate variability confers risk for poor health (Thayer &Lane, 2007; Thayer & Sternberg, 2006). Furthermore, reducedself-regulatory capacity is related to many negative emotional,interpersonal, and behavioral outcomes (e.g., Tangney et al.,2004). Hence, reduced regulatory capacity can undermine healthdirectly and could leave women susceptible to lapses in healthbehavior and more vulnerable to a variety of difficulties, includinginterpersonal stressors within and beyond the marriage. Self-regulatory depletion could also explain why relationships that areperceived as requiring high effort but providing limited rewardsare associated with poor health (Chandola, Marmot, & Siegrist,2007) and why reports of greater inhibition of negative behaviorduring marital conflict are associated with increased mortality riskamong women (Eaker et al., 2007).

Men responded to disagreement with attenuated decreases inPEP and less heart rate reactivity when it followed a positivemarital interaction, compared to the neutral or negative initialtasks. That is, men displayed less sympathetic activation andcardiovascular reactivity during marital disagreement when it fol-lowed a positive interaction with their spouse. However, womendid not display these effects of a prior positive marital interaction.This is consistent with the general hypothesis that men enjoybenefits of marriage that do not accrue to women (Kiecolt-Glaser& Newton, 2001).

Limitations and Qualifications

Several aspects of our methods and findings warrant caution.First, we did not control respiration rate or depth, which can alterthe validity of HF-HRV as an index of RSA (Beda, Jandre,Phillips, Giannella-Neto, & Simpson, 2007; Berntson et al., 1997).However, HF-HRV is often not highly susceptible to such artifacts(Denver, Reed, & Porges, 2007; Kotani, Tachibana, & Takamasu,2007). Furthermore, effects on resting HF-HRV occurred during asilent baseline less prone to such artifacts, and the effects onHF-HRV during disagreement were similar across periods thatvaried widely in respiratory artifacts—including silent preparation.

It is important to note again that we did not directly manipulateor measure self-regulation, and other psychological factors couldcontribute to the observed effects on HF-HRV. However, somealternatives such as negative affect or general arousal (Frazier etal., 2004) would have produced a decrease in HF-HRV duringdisagreement, rather than the observed increase. Also, the decreasein women’s resting HF-HRV following the negative task mightreflect greater stress or arousal, as worry has similar effects onHF-HRV (Hofmann et al., 2005). However, there were no parallelchanges in resting PEP, nor any increases in negative affect acrossthe two baseline periods. Furthermore, wives’ own emotionalreactions to the first task were not independently related to their

114 SMITH ET AL.

change in resting HF-HRV, whereas their husbands’ emotionalreactions were.

The negative initial task did not evoke concurrent increases inwives’ HF-HRV (Nealey-Moore et al., 2007), inconsistent withpredicted sex differences in self-regulation during relationshipstressors. However, ancillary analyses indicated that husbands’negative affect and their perceptions of wives as actively engagedin the task mediated the decrease in women’s resting HF-HRV,supporting the self-regulatory interpretation. Yet it is unclear howself-regulatory capacity was temporarily depleted during the neg-ative task without psychophysiological evidence of increased self-regulatory effort.

The reductions in resting HF-HRV were small and presumablytransient. Hence, implications for effects on resting HF-HRVsufficient to alter health and well-being are speculative. Theseeffects should be tested in prospective designs and models ofchronic relationship difficulties. Furthermore, our structured taskprocedures (e.g., alternating speaking and listening periods) pro-duced somewhat artificial couple interactions, perhaps reducingthe extent to which similar associations would occur in couples’actual daily lives. Yet short-term behavioral and physiologicalresponses during marital interaction procedures similar to thoseused here can predict marital outcomes, even many years later(Gottman & Levenson, 1992; Heyman, 2001; Kiecolt-Glaser,Bane, Glaser, & Malarkey, 2003).

We interpreted the results as indicating that women respondedto the initial negative task with a decrease in self-regulatorycapacity followed by greater self-regulatory effort during disagree-ment. Using the muscle metaphor, it seems inconsistent to suggesta temporarily fatigued muscle could display a more robust re-sponse. However, greater motivation and incentives to exert self-control can sometimes overcome the prior depletion of self-regulatory capacity (cf. Muraven & Slessareva, 2003).Nonetheless, future research should examine further the effectsself-regulatory effort on resting HF-HRV, as well as the associa-tion between temporary reductions in resting HF-HRV and themagnitude of responses to subsequent self-regulatory efforts.

Baumeister and colleagues (2006) demonstrated that self-regulatory capacity can be strengthened by practice. This raises aquestion as to whether wives’ apparently greater self-regulationefforts in marriage might actually improve their capacity over timerather than deplete it. It is possible that some types of effort toexert self-regulation in relationships deplete this capacity, whereasothers enhance it (John & Gross, 2007). Also, the depleting versusstrengthening effects may be influenced by contextual aspects ofthe marriage (e.g., chronic strain, levels of positivity) or thesuccess of those efforts.

We have suggested that efforts to regulate the tone of potentiallydiscordant marital interactions can have deleterious effects forwomen. Yet one obvious alternative—unchecked expression ofnegativity—predicts deteriorating marital quality (Fincham &Beach, 1999; Snyder et al., 2005), as well as emotional andphysical health problems (Beach, 2001; Kiecolt-Glaser & Newton,2001). Furthermore, self-regulation directed toward marital qualityis generally associated with positive relationship outcomes (Hal-ford et al., 2007; Wilson, Charker, Lizzio, Halford, & Kimlin,2005). However, there are many types of relationship regulation(Wilson et al., 2005), and some forms may be more adaptive thanothers. Suppressing expression of negative emotion is often more

maladaptive than other forms of self-regulation, such as alteringappraisals of events or preventing exposure to stressors (John &Gross, 2007). Aspects of self-regulation that are costly in terms ofshort-term physiology might also be maladaptive in terms oflonger term stress (Eaker et al., 2007; Gross & John, 2003; Overallet al., 2009; Vohs et al., 2005).

Also, we examined these processes in only one close relation-ship context, and other relationships are important for health andwell-being. For example, relational self-regulation may be relevantto the emotional or physical health effects of parenting stress orcaregiving (Schulz & Beach, 1999). Furthermore, relationships oflesbian and gay couples are similar to heterosexual relationships inmany respects (Peplau & Fingerhut, 2007), but efforts to maintainrelationship quality could be distributed quite differently.

Conclusions, Implications, and Future Directions

These limitations and qualifications notwithstanding, thepresent results suggest that women may respond to stressful mar-ital interactions with self-regulatory effort and temporary reduc-tions in resting HF-HRV, indicating a depletion of self-regulatorycapacity. Reduced capacity for self-regulation following relation-ship stressors could render women more susceptible to lapses inself-control and in turn contribute to poor health behavior, greateremotional dysfunction, and increased interpersonal difficulties. Ifreductions in resting HF-HRV due to marital strain are recurringand sustained, then this parasympathetic mechanism could alsocontribute directly to serious health problems.

When facing relationship difficulties women and their partnersmay experience more easily provoked and less easily managedconflicts over time, as self-regulatory capacities are depleted.Reciprocity of negative behavior during disagreement is a hall-mark of marital dysfunction (Fincham & Beach, 1999; Snyder etal., 2005), perhaps reflecting diminished self-regulatory capacityas frequent and prolonged efforts to navigate difficulties depletethis limited resource and leave couples less able to modulate theirbehavior (DeWall et al., 2007; Finkel et al., 2009; Stuke &Baumeister, 2006; Vohs et al., 2005). Hence, models of relation-ship dysfunction might be usefully expanded to include the poten-tial mediating role of self-regulatory capacity and HF-HRV.

If social stressors diminish self-regulatory capacity and dimin-ished self-regulatory capacity in turn increases exposure and reac-tivity to social stressors, these reciprocal associations have impor-tant implications for understanding health and well-being.Individual differences in negative affect (e.g., depression, anger,anxiety) are associated with low HF-HRV (Thayer & Brosschot,2005), perhaps reflecting diminished self-regulatory resources(Tangney et al., 2004). These emotional traits also confer risk forstrain in close relationships, and such strain can contribute to thesesame emotional difficulties (K. G. Baron et al., 2007; Beach, 2001;Rogge, Bradbury, Halweg, Engl, & Thurmaier, 2006). Hence,emotional distress may be reciprocally related to difficulties inclose relationships, at least in part, through the common mecha-nism of diminished capacity for self-regulation (Williams, Suchy,& Rau, 2009). In the search for mechanisms linking the quality ofclose relationships with physical and emotional health, parasym-pathetic processes and the capacity for self-regulation should beexamined as additional pathways through which relationships getunder the skin (Taylor, Repetti, & Seeman, 1997).

115MATTERS OF THE VARIABLE HEART

References

Acitelli, L. K. (1992). Gender differences in relationship awareness and maritalsatisfaction among young married couples. Personality and Social Psychol-ogy Bulletin, 18, 102–110. doi:10.1177/0146167292181015

Ahern, G. L., Sollers, J. J., Lane, R. D., Labiner, D. M., Herring, A. M.,Weinand, M. E., . . . Thayer, J. F. (2001). Heart rate and heart ratevariability changes in the intracarotid sodium amobarbital test. Epilep-sia, 42, 912–921. doi:10.1046/j.1528-1157.2001.042007912.x

Appelhans, B. M., & Luecken, L. J. (2006). Heart rate variability as anindex of regulated emotional responding. Review of General Psychol-ogy, 10, 229–240. doi:10.1037/1089-2680.10.3.229

Austin, M. A., Riniolo, T. C., & Porges, S. W. (2007). Borderline person-ality disorder and emotion regulation: Insights from polyvagal theory.Brain and Cognition, 65, 69–76. doi:10.1016/j.bandc.2006.05.007

Baron, K. G., Smith, T. W., Butner, J., Nealey-Moore, J., Hawkins, M. W.,& Uchino, B. (2007). Hostility, anger, and marital adjustment: Concur-rent and prospective associations with psychosocial vulnerability. Jour-nal of Behavioral Medicine, 30, 1–10. doi:10.1007/s10865-006-9086-z

Baron, R. M., & Kenny, D. A. (1986). The moderator–mediator variabledistinction in social psychological research: Conceptual, strategic, andstatistical considerations. Journal of Personality and Social Psychology,51, 1173–1182. doi:10.1037/0022-3514.51.6.1173

Baumeister, R. F., Gailliot, M., DeWall, N., & Oaten, M. (2006). Self-regulation and personality: How interventions increase regulatory suc-cess, and how depletion moderates the effects of traits on behavior.Journal of Personality, 74, 1773–1802. doi:10.1111/j.1467-6494.2006.00428.x

Beach, S. R. H. (2001). Marital and family processes in depression: Ascientific foundation for clinical practice. Washington, DC: AmericanPsychological Association. doi:10.1037/10350-000

Beda, A., Jandre, F. C., Phillips, D. W., Giannella-Neto, A., & Simpson,D. M. (2007). Heart rate and blood pressure variability during psycho-physiological tasks involving speech: Influence of respiration. Psycho-physiology, 44, 767–778. doi:10.1111/j.1469-8986.2007.00542.x

Bernhardson, C. S. (1975). Type I error rates when multiple comparisonsfollow a significant F test in AVOVA. Biometrics, 31, 229–232. doi:10.2307/2529724

Berntson, G. G., Bigger, J. T., Eckberg, D. L., Grossman, P., Kaufmann,P. G., Malik, M., . . . van der Molen, M. W. (1997). Heart rate variabil-ity: Origins, methods, and interpretive caveats. Psychophysiology, 34,623–648. doi:10.1111/j.1469-8986.1997.tb02140.x

Berntson, G. G., Cacioppo, J. T., & Quigley, K. S. (1994). The metrics ofcardiac chronotropism: Biometric perspectives. Psychophysiology, 31,44–61. doi:10.1111/j.1469-8986.1994.tb01024.x

Berntson, G. G., Quigley, K. S., Jang, J., & Boysen, S. T. (1990). An approachto artifact identification: Application to heart period data. Psychophysiology,27, 586–598. doi:10.1111/j.1469-8986.1990.tb01982.x

Butler, E. A., Wilhelm, F. H., & Gross, J. J. (2006). Respiratory sinusarrhythmia, emotion, and emotion regulation during social interaction.Psychophysiology, 43, 612–622. doi:10.1111/j.1469-8986.2006.00467.x

Cacioppo, J. T., Uchino, B. N., & Bernston, G. G. (1994). Individualdifferences in the autonomic origins of heart rate reactivity: The psy-chometrics of respiratory sinus arrhythmia and pre-ejection period. Psy-chophysiology, 31, 412–419. doi:10.1111/j.1469-8986.1994.tb02449.x

Campo, R. A., Uchino, B. N., Holt-Lunstad, J., Vaughn, A. A., Reblin, M.,& Smith, T. W. (2009). The assessment of positivity and negativity insocial networks: The reliability and validity of the Social RelationshipsIndex. Journal of Community Psychology, 37, 471–486. doi:10.1002/jcop.20308

Chandola, T., Marmot, M., & Siegrist, J. (2007). Failed reciprocity in closerelationships and health: Findings from the Whitehall II study. Journal ofPsychosomatic Research, 63, 403– 411. doi:10.1016/j.jpsychores.2007.07.012

Chida, Y., & Steptoe, A. (2010). Greater cardiovascular reactivity re-

sponses to laboratory stress are associated with poor subsequent cardio-vascular risk status: A meta-analysis of prospective evidence. Hyperten-sion, 55, 1026–1032. doi:10.1161/HYPERTENSIONAHA.109.146621

Christensen, A., Elderidge, K., Catta-Preta, A., Lim, V., & Sanagata, R.(2006). Cross-cultural consistency of the demand/withdraw interactionpattern in couples. Journal of Marriage and Family, 68, 1029–1044.doi:10.1111/j.1741-3737.2006.00311.x

Demaree, H. A., & Everhart, D. E. (2004). Healthy high-hostiles: Reducedparasympathetic activity and decreased sympathovagal flexibility duringnegative emotional processing. Personality and Individual Differences,36, 457–469. doi:10.1016/S0191-8869(03)00109-0

Denton, W. H., & Burleson, B. R. (2007). The Initiator Style Question-naire: A scale to assess initiator tendency in couples. Personal Relation-ships, 14, 245–268. doi:10.1111/j.1475-6811.2007.00153.x

Denver, J. W., Reed, S. F., & Porges, S. W. (2007). Methodological issuesin the quantification of respiratory sinus arrhythmia. Biological Psychol-ogy, 74, 286–294. doi:10.1016/j.biopsycho.2005.09.005

De Vogli, R., Chandola, T., & Marmot, M. G. (2007). Negative aspects ofclose relationships and heart disease. Archives of Internal Medicine, 167,1951–1957. doi:10.1001/archinte.167.18.1951

DeWall, C. N., Baumeister, R. F., Stillman, T. F., & Gailliot, M. T. (2007).Violence restrained: Effects of self-regulation and its depletion on ag-gression. Journal of Experimental Social Psychology, 43, 62–76. doi:10.1016/j.jesp.2005.12.005

Diamond, L. M., & Hicks, A. M. (2005). Attachment style, current rela-tionship security, and negative emotions: The mediating role of physi-ological regulation. Journal of Social and Personal Relationships, 22,499–518. doi:10.1177/0265407505054520

Eaker, E. D., Sullivan, L. M., Kelly-Hayes, M., D’Agostino, R., & Ben-jamin, E. (2007). Marital status, marital strain, and risk of coronary heartdisease or total mortality: The Framingham Offspring Study. Psychoso-matic Medicine, 69, 509–513. doi:10.1097/PSY.0b013e3180f62357

Egizio, V. B., Jennings, J. R., Christie, I. C., Sheu, L. K., Matthews, K. A.,& Gianaros, P. J. (2008). Cardiac vagal activity during psychosocialstress varies with social functioning in older women. Psychophysiology,45, 1046–1054. doi:10.1111/j.1469-8986.2008.00698.x

Erickson, R. J. (2005). Why emotion work matters: Sex, gender, and thedivision of household labor. Journal of Marriage and Family, 67,337–351. doi:10.1111/j.0022-2445.2005.00120.x

Fabes, R. A., & Eisenberg, N. (1997). Regulatory control and adults’stress-related responses to daily life events. Journal of Personality andSocial Psychology, 73, 1107–1117. doi:10.1037/0022-3514.73.5.1107

Fincham, F. D., & Beach, S. R. H. (1999). Conflict in marriage: Implica-tions for working with couples. Annual Review of Psychology, 50,47–77. doi:10.1146/annurev.psych.50.1.47

Finkel, E. J., & Campbell, W. K. (2001). Self-control and accommodationin close relationships: An interdependence analysis. Journal of Person-ality and Social Psychology, 81, 263–277. doi:10.1037/0022-3514.81.2.263

Finkel, E. J., Campbell, W. K., Brunell, A. B., Dalton, A. N., Scarbeck,S. J., & Chartrand, T. L. (2006). High-maintenance interaction: Ineffi-cient social coordination impairs self-regulation. Journal of Personalityand Social Psychology, 91, 456–475. doi:10.1037/0022-3514.91.3.456

Finkel, E. J., DeWall, C. N., Slotter, E. B., Oaten, M., & Foshee, V. A.(2009). Self-regulatory failure and intimate partner violence perpetra-tion. Journal of Personality and Social Psychology, 97, 483–499. doi:10.1037/a0015433

Frazier, T. W., Strauss, M. E., & Steinhauer, S. R. (2004). Respiratorysinus arrhythmia as an index of emotional response in young adults.Psychophysiology, 41, 75–83. doi:10.1046/j.1469-8986.2003.00131.x

Gallo, L. C., Smith, T. W., & Kircher, J. C. (2000). Cardiovascular andelectrodermal responses to support and provocation: Interpersonal meth-ods in the study of psychophysiologic reactivity. Psychophysiology, 37,289–301. doi:10.1017/S0048577200982222

116 SMITH ET AL.

Gianaros, P. J., Van Der Veen, F. M., & Jennings, J. R. (2004). Regionalcerebral blood flow correlates with heart period and high-frequencyheart period variability during working-memory tasks: Implications forthe cortical and subcortical regulation of cardiac autonomic activity.Psychophysiology, 41, 521–530. doi:10.1111/1469-8986.2004.00179.x

Goldin, P. R., McRae, K., Ramel, W., & Gross, J. J. (2008). The neural basesof emotion regulation: Reappraisal and suppression of negative emotion.Biological Psychiatry, 63, 577–586. doi:10.1016/j.biopsych.2007.05.031

Gottman, J. M., & Levenson, R. W. (1992). Marital processes predictive oflater dissolution: Behavior, physiology, and health. Journal of Person-ality and Social Psychology, 63, 221–233. doi:10.1037/0022-3514.63.2.221

Gottman, J. M., Markman, H., & Notarious, C. (1977). The topography ofmarital conflict: A sequential analysis of verbal and nonverbal behavior.Journal of Marriage and Family, 39, 461–477. doi:10.2307/350902

Greenhouse, S. W., & Geisser, S. (1959). On methods in the analysis ofprofile data. Psychometrika, 24, 95–112. doi:10.1007/BF02289823

Grippo, A. J., Lamb, D. G., Carter, C. S., & Porges, S. W. (2007). Socialisolation disrupts autonomic regulation of the heart and influencesnegative affective behaviors. Biological Psychiatry, 62, 1162–1170.doi:10.1016/j.biopsych.2007.04.011

Gross, J. J., & John, O. P. (2003). Individual differences in two emotionregulation strategies: Implications for affect, relationships, and well-being. Journal of Personality and Social Psychology, 85, 348–361.

Gyurak, A., & Ayduk, O. (2008). Resting respiratory sinus arrhythmiabuffers against rejection sensitivity via emotion regulation. Emotion, 8,458–467. doi:10.1037/1528-3542.8.4.458

Halford, W. K., Lizzio, A., Wilson, K. L., & Occhipinti, S. (2007). Doesworking at your marriage help? Couple relationship self-regulation andsatisfaction in the first 4 years of marriage. Journal of Family Psychol-ogy, 21, 185–194. doi:10.1037/0893-3200.21.2.185

Hansen, A. L., Johnsen, B. H., & Thayer, J. F. (2003). Vagal influence onworking memory and attention. International Journal of Psychophysi-ology, 48, 263–274. doi:10.1016/S0167-8760(03)00073-4

Heyman, R. E. (2001). Observation of couple conflicts: Clinical assess-ment applications, stubborn truths, and shaky foundations. Psychologi-cal Assessment, 13, 5–35. doi:10.1037/1040-3590.13.1.5

Hofmann, S. G., Moscovitch, D. A., Litz, B. T., Kim, H., Davis, L., &Lizzagalli, D. A. (2005). The worried mind: Autonomic and prefrontalactivation during worrying. Emotion, 5, 464–475. doi:10.1037/1528-3542.5.4.464

Horsten, M., Ericson, M., Perski, A., Wamala, S. P., Schenck-Gustafsson,K., & Orth-Gomer, K. (1999). Psychosocial factors and heart ratevariability in healthy women. Psychosomatic Medicine, 61, 49–57.

Hughes, J. W., & Stoney, C. M. (2000). Depressed mood is related tohigh-frequency heart rate variability during stressors. PsychosomaticMedicine, 62, 796–803.

Impett, E. A., & Peplau, L. A. (2006). “His” and “her” relationships? Areview of the empirical literature. In A. L. Vangelisti & D. Perlman(Eds.), The Cambridge handbook of personal relationships (pp. 273–291). New York, NY: Cambridge University Press.

Ingjaldsson, J. T., Laberg, J. C., & Thayer, J. F. (2003). Reduced heart ratevariability in chronic alcohol abuse: Relationship with negative mood,chronic thought suppression, and compulsive drinking. Biological Psy-chiatry, 54, 1427–1436. doi:10.1016/S0006-3223(02)01926-1

Jamieson, J. (2004). Analysis of covariance (ANCOVA) with differencescores. International Journal of Psychophysiology, 52, 277–283. doi:10.1016/j.ijpsycho.2003.12.009

John, O. P., & Gross, J. J. (2007). Individual differences in emotionregulation. In J. J. Gross (Ed.), Handbook of emotion regulation (pp.351–372). New York, NY: Guilford Press.

Kaplan, R. M., & Kronick, R. G. (2006). Marital status and longevity in theUnited States population. Journal of Epidemiology and CommunityHealth, 60, 760–765. doi:10.1136/jech.2005.037606

Kelly, E. L., & Conley, J. J. (1987). Personality and compatibility: Aprospective analysis of marital stability and marital satisfaction. Journalof Personality and Social Psychology, 52, 27–40. doi:10.1037/0022-3514.52.1.27

Kenny, D. A. (1995). Design and analysis issues in dyadic research. Reviewof Personality and Social Psychology, 11, 164–184.

Kiecolt-Glaser, J. K., Bane, C., Glaser, R., & Malarkey, W. B. (2003).Love, marriage, and divorce: Newlyweds’ stress hormones foreshadowrelationship changes. Journal of Consulting and Clinical Psychology,71, 176–188. doi:10.1037/0022-006X.71.1.176

Kiecolt-Glaser, J. K., Loving, T. J., Stowell, J. R., Malarkey, W. B.,Lemeshow, S., Dickinson, S. L., & Glaser, R. (2005). Hostile maritalinteractions, proinflammatory cytokine production, and wound healing.Archives of General Psychiatry, 62, 1377–1384. doi:10.1001/archpsyc.62.12.1377

Kiecolt-Glaser, J. K., & Newton, T. L. (2001). Marriage and health: Hisand hers. Psychological Bulletin, 127, 472–503. doi:10.1037/0033-2909.127.4.472

Kiesler, D. J., Schmidt, J. A., & Wagner, C. C. (1997). A circumplexinventory of impact messages: An operational bridge between emotionand interpersonal behavior. In R. Plutchik & H. R. Conte (Eds.), Cir-cumplex models of personality and emotions (pp. 221–244). Washing-ton, DC: American Psychological Association. doi:10.1037/10261-010

Kotani, K., Tachibana, M., & Takamasu, K. (2007). Investigation of theinfluence of swallowing, coughing and vocalization on heart rate vari-ability with respiratory-phase domain analysis. Methods of Informationin Medicine, 46, 179–185.

Lindahl, K. M., & Markman, H. J. (1990). Communication and negativeaffect regulation in the family. In E. A. Blechman (Ed.), Emotions andthe family: For better or for worse (pp. 99–115). Hillsdale, NJ: Erlbaum.

Litvack, D. A., Oberlander, T. F., Carney, L. H., & Saul, J. P. (1995). Timeand frequency domain methods for heart rate variability analysis: Amethodological comparison. Psychophysiology, 32, 492–504. doi:10.1111/j.1469-8986.1995.tb02101.x

Llabre, M. M., Spitzer, S. B., Saab, P. G., Ironson, G. H., & Schneiderman,N. (1991). The reliability and specificity of delta versus residualizedchange as measures of cardiovascular reactivity to behavioral chal-lenges. Psychophysiology, 28, 701–711. doi:10.1111/j.1469-8986.1991.tb01017.x

MacKinnon, D. P., Lockwood, C. M., Huffman, J. M., West, S. G., &Sheets, V. (2002). A comparison of methods to test the significance ofthe mediated effect. Psychological Methods, 7, 83–104. doi:10.1037/1082-989X.7.1.83

Matthews, K. A., & Gump, B. B. (2002). Chronic work stress and maritaldissolution increase risk of post-trial mortality in men from the MultipleRisk Factor Intervention Trial. Archives of Internal Medicine, 162,309–315. doi:10.1001/archinte.162.3.309

Matthews, S. C., Paulus, M. P., Simmons, A. N., Nelesen, R. A., &Dimsdale, J. E. (2004). Functional subdivisions within anterior cingulatecortex and their relationship to autonomic nervous system function.NeuroImage, 22, 1151–1156. doi:10.1016/j.neuroimage.2004.03.005

Muraven, M., & Baumeister, R. F. (2000). Self-regulation and depletion oflimited resources: Does self-control resemble a muscle? PsychologicalBulletin, 126, 247–259. doi:10.1037/0033-2909.126.2.247

Muraven, M., & Slessareva, E. (2003). Mechanisms of self-control failure:Motivation and limited resources. Personality and Social PsychologyBulletin, 29, 894–906. doi:10.1177/0146167203029007008

Nealey-Moore, J. B., Smith, T. W., Uchino, B. N., Hawkins, M. W., &Olson-Cerny, C. (2007). Cardiovascular reactivity during positive andnegative marital interactions. Journal of Behavioral Medicine, 30, 505–519. doi:10.1007/s10865-007-9124-5

Neuvo, Y., Cheng-Yu, D., & Mitra, S. (1984). Interpolated finite impulseresponse filters. IEEE Transactions on Acoustics, Speech, and SignalProcessing, 32, 563–570. doi:10.1109/TASSP.1984.1164348

117MATTERS OF THE VARIABLE HEART

Niven, K., Totterdell, P., & Holman, D. (2009). A classification of con-trolled interpersonal affect regulation strategies. Emotion, 9, 498–509.doi:10.1037/a0015962

Nolen-Hoeksema, S., & Jackson, B. (2001). Mediators of the genderdifference in rumination. Psychology of Women Quarterly, 25, 37–47.doi:10.1111/1471-6402.00005

Ochsner, K. N., & Gross, J. J. (2007). The neural architecture of emotionregulation. In J. J. Gross (Ed.), Handbook of emotion regulation (pp.87–109). New York, NY: Guilford Press.

Overall, N. C., Fletcher, G. J. O., & Simpson, J. A. (2006). Regulationprocesses in intimate relationships: The role of ideal standards. Journalof Personality and Social Psychology, 91, 662–685. doi:10.1037/0022-3514.91.4.662

Overall, N. C., Fletcher, G. J. O., Simpson, J. A., & Sibley, C. (2009).Regulating partners in intimate relationships: The costs and benefits ofdifferent communication strategies. Journal of Personality and SocialPsychology, 96, 620–639. doi:10.1037/a0012961

Peplau, L. A., & Fingerhut, A. W. (2007). The close relationships oflesbians and gay men. Annual Review of Psychology, 58, 405–424.doi:10.1146/annurev.psych.58.110405.085701

Pierce, G. R., Sarason, I. G., & Sarason, B. R. (1997). Assessing the qualityof personal relationships. Journal of Social and Personal Relationships,14, 339–356. doi:10.1177/0265407597143004

Porges, S. W. (2001). The polyvagal theory: Phylogenetic substrates of asocial nervous system. International Journal of Psychophysiology, 42,123–146. doi:10.1016/S0167-8760(01)00162-3

Porges, S. W. (2007). The polyvagal perspective. Biological Psychology,74, 116–143. doi:10.1016/j.biopsycho.2006.06.009

Posner, M. I., & Rothbart, M. K. (2007). Research on attention networks asa model for the integration of psychological science. Annual Review ofPsychology, 58, 1–23. doi:10.1146/annurev.psych.58.110405.085516

Pu, J., Schmeichel, B. J., & Demaree, H. A. (2009). Cardiac vagal controlpredicts spontaneous regulation of negative emotional expression andsubsequent cognitive performance. Biological Psychology, 82, 186–195.

Radloff, L. S. (1977). The CES-D Scale: A self-report depression scale forresearch in the general population. Applied Psychological Measurement,1, 385–401. doi:10.1177/014662167700100306

Robles, T. F., & Kiecolt-Glaser, J. K. (2003). The physiology of marriage:Pathways to health. Physiology & Behavior, 79, 409–416. doi:10.1016/S0031-9384(03)00160-4

Rogge, R. D., Bradbury, T. N., Halweg, K., Engl, J., & Thurmaier, F.(2006). Predicting marital distress and dissolution: Refining the two-factor hypothesis. Journal of Family Psychology, 20, 156–159. doi:10.1037/0893-3200.20.1.156

Sahar, T., Shalev, A. Y., & Porges, S. W. (2001). Vagal modulation ofresponses to mental challenge in posttraumatic stress disorder. Biologi-cal Psychiatry, 49, 637–643. doi:10.1016/S0006-3223(00)01045-3

Schulz, R., & Beach, S. R. (1999). Caregiving as a risk factor for mortality:The Caregiver Health Effects Study. JAMA, 282, 2215–2219. doi:10.1001/jama.282.23.2215

Schwartz, A. R., Gerin, W., Davidson, K., Pickering, T., Brosschot, J., Thayer,J., . . . Linden, W. (2003). Toward a causal model of cardiovascular re-sponses to stress and the development of cardiovascular disease. Psycho-somatic Medicine, 65, 22–35. doi:10.1097/01.PSY.0000046075.79922.61

Segerstrom, S. C., & Nes, L. S. (2007). Heart rate variability reflectsself-regulatory strength, effort, and fatigue. Psychological Science, 18,275–281. doi:10.1111/j.1467-9280.2007.01888.x

Sherwood, A., Allen, M. T., Fahrenberg, J., Kelsey, R. M., Lovallo, W. R.,& van Doornen, L. J. P. (1990). Methodological guidelines for imped-ance cardiography. Psychophysiology, 27, 1–23. doi:10.1111/j.1469-8986.1990.tb02171.x

Sloan, R. P., Shapiro, P. A., Bigger, J. T., Bagiella, E., Steinman, R. C., &Gorman, J. C. (1994). Cardiac autonomic control and hostility in healthy

subjects. American Journal of Cardiology, 74, 298–300. doi:10.1016/0002-9149(94)90382-4

Smith, A. W., & Baum, A. (2003). The influence of psychological factorson restorative function in health and illness. In. J. Suls & K. Wallston(Eds.), Social psychological foundations of health and illness (pp. 432–457). Oxford, England: Oxford University Press. doi:10.1002/9780470753552.ch16

Smith, T. W., Uchino, B. N., Berg, C. A., Florsheim, P., Pearce, G.,Hawkins, M., . . . Olson-Cerny, C. (2009). Conflict and collaboration inmiddle-aged and older married couples: II. Age, sex, and task contextmoderate cardiovascular reactivity during marital interaction. Psychol-ogy and Aging, 24, 274–286. doi:10.1037/a0016067

Snyder, D. K., Heyman, R. E., & Haynes, S. N. (2005). Evidence-basedapproaches to assessing couple distress. Psychological Assessment, 17,288–307. doi:10.1037/1040-3590.17.3.288

Snyder, D. K., Simpson, J. A., & Hughes, J. N. (Eds.). (2006). Emotionregulation in couples and families. Washington, DC: American Psycho-logical Association. doi:10.1037/11468-000

Spielberger, C. D. (1980). Preliminary manual for the State-Trait Person-ality Inventory. Tampa, FL: University of South Florida, Human Re-sources Institute.

Strazdins, L., & Broom, D. H. (2004). Acts of love (and work): Genderimbalance in emotional work and women’s psychological distress. Jour-nal of Family Issues, 25, 356–378. doi:10.1177/0192513X03257413

Stucke, T. S., & Baumeister, R. F. (2006). Ego depletion and aggressivebehavior: Is the inhibition of aggression a limited resource? EuropeanJournal of Social Psychology, 36, 1–13.

Suchy, Y. (2009). Executive functioning: Overview, assessment, and re-search issues for non-neuropsychologists. Annals of Behavioral Medi-cine, 37, 106–116. doi:10.1007/s12160-009-9097-4

Tangney, J. P., Baumeister, R. F., & Boone, A. L. (2004). High self-controlpredicts good adjustment, less pathology, better grades, and interper-sonal success. Journal of Personality, 72, 271–324. doi:10.1111/j.0022-3506.2004.00263.x

Taylor, S. E., Cousino Klein, L., Lewis, B. P., Grunewald, T. L., Gurung,R. A. R., & Updegraff, J. A. (2000). Biobehavioral responses to stress infemales: Tend-and-befriend, not fight-or-flight. Psychological Review, 107,411–429. doi:10.1037/0033-295X.107.3.411

Taylor, S. E., Repetti, R. L., & Seeman, T. (1997). Health psychology:What is an unhealthy environment and how does it get under the skin?Annual Review of Psychology, 48, 411– 447. doi:10.1146/annurev.psych.48.1.411

Thayer, J. F., & Brosschot, J. (2005). Psychosomatics and psychopathol-ogy: Looking up and looking down from the brain. Psychoneuroendo-crinology, 30, 1050–1058.

Thayer, J. F., Hansen, A. L., & Johnsen, B. H. (2008). Non-invasiveassessment of autonomic influences on the heart: Impedance cardiogra-phy and heart rate variability. In L. Leuken & L. C. Gallo (Eds.),Handbook of physiological research methods in health psychology (pp.183–209). Thousand Oaks, CA: Sage.

Thayer, J. F., Hansen, A. L., Saus-Rose, E., & Johnsen, B. H. (2009). Heartrate variability, prefrontal neural function, and cognitive performance:The neurovisceral integration perspective on self-regulation, adaptation,and health. Annals of Behavioral Medicine, 37, 141–153. doi:10.1007/s12160-009-9101-z

Thayer, J. F., & Lane, R. D. (2000). A model of neurovisceral integrationin emotion regulation and dysregulation. Journal of Affective Disorders,61, 201–216. doi:10.1016/S0165-0327(00)00338-4

Thayer, J. F., & Lane, R. D. (2007). The role of vagal function in the riskfor cardiovascular disease and mortality. Biological Psychology, 74,224–242. doi:10.1016/j.biopsycho.2005.11.013

Thayer, J. F., & Lane, R. D. (2009). Claude Bernard and the heart–brainconnection: Further elaboration of a model of neurovisceral integration.

118 SMITH ET AL.

Neuroscience & Biobehavioral Reviews, 33, 81– 88. doi:10.1016/j.neubiorev.2008.08.004

Thayer, J. F., & Sternberg, E. (2006). Beyond heart rate variability: Vagalregulation of allostatic systems. Annals of the New York Academy ofScience, 1088, 361–372. doi:10.1196/annals.1366.014

Tobe, S. W., Kiss, A., Sainsbury, S., Jesin, M., Geerts, R., & Baker, B. (2007).The impact of job strain and marital cohesion on ambulatory blood pressureduring 1 year: The Double Exposure Study. American Journal of Hyper-tension, 20, 148–153. doi:10.1016/j.amjhyper.2006.07.011

Vohs, K. D., Baumeister, R. F., & Ciarocco, N. J. (2005). Self-regulationand self-presentation: Regulatory resource depletion impairs impressionmanagement and effortful self-presentation depletes regulatory re-sources. Journal of Personality and Social Psychology, 88, 632–657.doi:10.1037/0022-3514.88.4.632

von Hippel, W. (2007). Aging, executive functioning, and social control.Current Directions in Psychological Science, 16, 240–244. doi:10.1111/j.1467-8721.2007.00512.x

Wiggins, J. S. (1996). An informal history of the interpersonal circumplex.Journal of Personality Assessment, 66, 217–233. doi:10.1207/s15327752jpa6602_2

Williams, P. G., Suchy, Y., & Rau, H. K. (2009). Individual differences inexecutive functioning: Implications for stress regulation. Annals of Be-havioral Medicine, 37, 126–140. doi:10.1007/s12160-009-9100-0

Wilson, K. L., Charker, J., Lizzio, A., Halford, K., & Kimlin, S. (2005).Assessing how much couples work at their relationship: The BehavioralSelf-Regulation for Effective Relationships Scale. Journal of FamilyPsychology, 19, 385–393. doi:10.1037/0893-3200.19.3.385

Received March 9, 2009Revision received April 26, 2010

Accepted April 28, 2010 �

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