Environmental Risk Factors in Infancy

SECTION 3. MANAGEMENT OF CLINICAL PROBLEMS ANDEMOTIONAL CARE

Environmental Risk Factors in Infancy

Arnold J. Sameroff, PhD

ABSTRACT. Environment plays an important role inshaping development from the newborn period throughadolescence. Many individual environmental risk factorsmay impinge on development (poverty, mental illness,minority status, and many others), but the most detri-mental effects are caused when multiple risk factors acton a single infant. These effects were revealed by theRochester Longitudinal Study, an ongoing comprehen-sive investigation of environmental risk factors, summarized in this article. Pediatrics 1998;102:12871292; mentalhealth, environmental risk factors, infant development,Rochester Longitudinal Study, socioeconomic status(SES).

ABBREVIATIONS. RLS, Rochester Longitudinal Study; SES, so-cioeconomic status.

The pursuit of happiness is a fundamental rightin our society, yet the goal of achieving a senseof satisfaction with ones abilities and achieve-ments is becoming increasingly elusive for large seg-ments of the population. Our interest in emotionaldevelopment in early childhood is in part a concernthat infants and toddlers be happy, but also a con-cern that this early evidence of mental health will bepredictive and continuous with happiness and men-tal health in later life. Yet greater than half of todays10- to 17-year-olds engage in two or more risk be-haviors, including unsafe sex, teenage pregnancy,drug or alcohol abuse, school failure, delinquency,and crimeand 10% of these youths engage in all ofthese risks.1 To what extent can these problems oflater life be attributed to emotional behavior duringearly childhood, and to what extent must we exam-ine intervening life circumstances as determinants oflater emotional behavior?

The roots of these failures are frequently attributedto environmental factors that undermine achieve-ment and mental health.2 Therefore, attention mustbe paid to the multiple contexts that support devel-opment in the family, the school, and the communityfrom infancy through adolescence. Moreover, fewstudies have tested directly the premise that it iscontinuing environmental adversity that underminesdevelopment. Many studies have examined the sta-

bility of child characteristics over time, but few haveexamined continuities of contextual risk. Brooks-Gunn and associates3 found the best predictor ofcompetence during early childhood was not the cur-rent economic circumstance of the family but thenumber of previous years that the family had spentin poverty. In the Rochester Longitudinal Study(RLS), we too have found long-term continuities inthe effects of social risk on children that shouldimprove our understanding of the relative contribu-tions of early emotional behavior and later environ-mental circumstance on mental health.

ASSESSING ENVIRONMENTSDespite the nominal interest of developmentalists

in the effects of the environment, the analysis andassessment of context have fallen more in the domainof sociology than of developmental psychology.46The magnitude of a social ecologic analysis involvingmultiple settings and multiple systems7 has dauntedresearchers trained primarily to focus on individualbehavioral processes. An additional daunting factorhas been the increasing need to use multicausal modelsto explain developmental phenomena.8,9

To examine the effects of the environment on earlyemotional behavior and later mental health, we be-gan an investigation of the development of a groupof children from the prenatal period through adoles-cence living in a socially heterogeneous set of familycircumstancesthe RLS. During the early childhoodphase of the RLS,10 we assessed children and theirfamilies at birth and then at 4, 12, 30, and 48 monthsof age, both in the home and in the laboratory. Dur-ing adolescence, we made new assessments of thefamilies when the children were 13 and 18 years old.At each age, we evaluated two major indicators ofdevelopmental status: the childs cognitive and socialemotional competence. Because many of the familieshad single parents, we focused our assessments oncharacteristics of the mother. This approach was takennot because we believed that fathers were unimportant,but because there were too few available for participa-tion in our study.

In the RLS, we hypothesized that differences infamily socioeconomic status (SES) would producedifferences in child behavior. We found these socialstatus effects throughout the first 4 years of life.Children from the poorest families in our sampleexhibited the poorest development. They had poorerobstetric status, more difficult temperaments, andlower developmental test scores at 4 months, less

Received for publication Aug 2, 1998; accepted Sep 29, 1998.Address correspondence to John G. Warhol, PhD, The Warhol Institute, 225First Ave, Atlantic Highlands, NJ 07716.PEDIATRICS (ISSN 0031 4005). Copyright 1998 by the American Acad-emy of Pediatrics.

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responsivity during the home and laboratory obser-vations at 12 months, and less adaptive behavior inthe home and laboratory at 30 and 48 months of age.

At the end of 4 years of development, we haddiscovered the effects of multiple risk factors. On onehand, if the only developmental risk for a child wasa mother with an emotional problem or who lackedsocial support or had a low educational level, usuallythe child was doing fine. On the other hand, if thechild had a mother who was mentally ill and poorand uneducated and without social supports, thatchild was doing poorly. What we learned was theoverriding importance of attending to the combina-tion of environmental adversity with the social con-text of children to understand their development. Tounderstand better the role of contextual factors, amore differentiated view of environmental influ-ences needed to be taken. We had to discover whatwas different about the experience of children raisedin different socioeconomic environments.

ENVIRONMENTAL CONDITIONS ASDEVELOPMENTAL RISKS

Although SES is the best single variable for pre-dicting childrens cognitive competence and animportant, if less powerful, predictor of socialemotional functioning, we decided to add more psy-chological content to this sociologic variable. SESoperates at many levels of the ecology of children. Itimpacts on parenting, parental attitudes and beliefs,family interactions, and many institutions in thecommunity. From the data available in the RLS, wesearched for a set of variables that were related toeconomic circumstance but not the same as SES. Thefactors we chose were from distal variables (such asthe financial resources of the family) to intermediatevariables (such as the mothers mental health) toproximal variables (such as the mothers here-and-now behavioral interaction with the child).

From the 4-year assessment of the children in theRLS, we chose a set of 10 environmental variablesthat were correlates of SES, but not equivalents.11We then tested whether poor cognitive and socialemotional development in our preschool childrenwas a function of the compounding of environmentalrisk factors found in low-SES groups. The definitionsof the 10 environmental risk variables are as follows:1) history of maternal mental illness; 2) high mater-nal anxiety; 3) parental perspectives that reflectedrigidity in the attitudes, beliefs, and values thatmothers had in regard to their childs development;

4) few positive maternal interactions with the childobserved during infancy; 5) head of household inunskilled occupations; 6) minimal maternal educa-tion; 7) disadvantaged minority status; 8) single par-enthood; 9) stressful life events; and 10) large familysize (Table 1).

We found, indeed, that each of these variables wasa risk factor. We compared the high-risk and low-risk groups for each variable separately. For both thecognitive and the mental health outcomes, the low-risk group had higher scores than did the high-riskgroup. Most of the differences were enough todemonstrate the effects for group comparisons, butcertainly not enough to detect which specific indi-viduals with the risk factor would have an adverseoutcome. Although statistically significant differ-ences in outcome are associated with single environ-mental risk factors, these differences rarely explainlarge proportions of outcome variance.

ACCUMULATING RISK FACTORSIn a much-cited study, Rutter12 argued that it was

not any particular risk factor but the number of riskfactors in a childs background that led to psychiatricdisorder. Psychiatric risk for a sample of 10-year-oldshe studied rose from 2% in families with zero or onerisk factor(s) to 20% in families with four or more.The six risk factors included severe marital distress,low SES, large family size or overcrowding, paternalcriminality, maternal psychiatric disorder, and ad-mission of the child to foster care. Another study13found similar results relating behavioral disorders in11-year-olds to a cumulative disadvantage scorebased on number of residence and school changes,single parenthood, low SES, marital separation,young motherhood, low maternal cognitive ability,poor family relations, seeking marriage guidance,and maternal mental health symptoms.

In the RLS, there were significant effects for thesingle risk factors, but it was clear that most childrenwith only a single risk factor would not end up witha major developmental problem. But how wouldchildren growing in environments with many riskfactors compare with children growing in environ-ments with very few? We created a multiple riskscore that was the total number of risks for eachindividual family. In the RLS, the range was well-distributed between scores of 0 and 8, with one fam-ily having as many as 9 risk factors. When these riskfactors were related to the childs intelligence and

TABLE 1. Summary of Risk Variables11

Risk Variables Low Risk High Risk

Mental illness 01 Psychiatric contact More than 1 contactAnxiety 75% Least 25% MostParental perspectives 75% Highest 25% LowestSpontaneous interaction 75% Most 25% LeastOccupation Skilled Semi- or unskilledEducation High school No high schoolMinority status No YesFamily support Father present Father absentStressful life events 75% Fewest 25% MostFamily size 13 Children Four or more children

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mental health, major differences were found betweenthose children with few risks and those with many.

The relation between the multiple risk scores andthe emotional health can be seen in Fig 1. It is clearthat the effect of combining the 10 risk variables wasto strongly accentuate the differences noted for theindividual scores described above. As the number ofrisk factors increased, performance decreased forchildren at 4 years of age. Thus, the combination ofrisk factors resulted in a nearly threefold increase inthe magnitude of differences found in groups ofchildren relative to the effect of single variables.14Similarly, on an intelligence test, children with noenvironmental risks scored .30 points higher thandid children with eight or nine risk factors.11 Onaverage, each risk factor reduced the childs IQ scoreby 4 points.

These analyses of the RLS data were attempts toelaborate environmental risk factors by reducingglobal measures such as SES to component social andbehavioral variables. We were able to identify a set ofrisk factors that were predominantly found in lowerSES groups but that affected child outcomes in allsocial classes. Moreover, no single variable was de-terminant of outcome. Only in families with multiplerisk factors was the childs competence placed injeopardy.

We found that the following all play a role in thecontemporary development of child intelligence testperformance and mental health: multiple pressuresof environmental stress, the familys resources forcoping with that stress, the number of children thatmust share those resources, and the parents flexibil-ity in understanding and dealing with their children.

CONTINUITY OF ENVIRONMENTAL RISKStudies such as the RLS that have explored the

effects of environmental risk factors on early devel-opment have shown major consequences for childrenliving in multiproblem families. What are the long-term consequences of these early adverse circum-stances? Will later conditions alter the course forsuch children or will early experiences lock childreninto pathways of deviance? To answer this question,we must return to a consideration of data from theadolescent phase of the RLS.

Within the RLS, our attention has been devoted tothe source of continuities and discontinuities in child

performance. We completed additional assessmentsof the sample when the children were 13 and 18years of age.15,16 Because of the potent effects of ourmultiple risk index at 4 years, we calculated newmultiple environmental risk scores for each familybased on their situation 9 and 14 years later. To oursurprise, there were very few families that showedmajor shifts in the number of risk factors across the9-year intervening period. Between 4 and 13 years,the factor that improved most was maternal educa-tion, for which the number of mothers without a highschool diploma or equivalent decreased from 33% to22%. The risk factor that increased the most wassingle parenthood, wherein the number of childrenbeing raised by the mother alone increased from 24%to 41%. On average, however, there was little changein the environments of the children in our sample.

The typical statistic reported in longitudinal re-search is the correlation between early and laterperformance of the children. We too found suchcorrelations. Mental health at 4 years correlated sig-nificantly with mental health at 13 years. Intelligenceat 4 years correlated even more strongly with intel-ligence at 13 years. The usual interpretation of suchnumbers is that there are continuities of competenceor incompetence in the child. Such a conclusion can-not be challenged if the only assessments are of thechildren. Fortunately, in the RLS we examined andwere also able to correlate environmental character-istics across time. We found a higher correlationbetween environmental risk scores at the two agesthat was as great or greater than any continuitywithin the child. Whatever the childs ability forachieving higher levels of competence, it was under-mined severely by the continuing paucity of environ-mental support in high-risk contexts and fosteredin low-risk contexts. Whatever the capabilitiesprovided to the child by individual factors, the en-vironment acted to limit or expand additional op-portunities for development.

Because of the very high stability in the number ofrisks experienced by these families, it was impossibleto determine whether the effects of early adversity orcontemporary risk were having the greater effect onthe later behavior of the children. Those childrenwho had been living in high-risk environments at 4years of age still were living in them at 13 years ofage. Moreover, these contemporary high-risk con-texts were producing the same negative effects onbehavior as did the earlier contexts.

SECULAR TRENDSThe thrust of a contextual analysis of developmen-

tal regulation is not that individual factors in thechild are nonexistent or irrelevant, but that they mustbe studied in a context larger than that of the singlechild. The risk analyses discussed thus far have im-plicated parent characteristics and the immediate so-cial conditions of family support and life event stressas important moderators of healthy psychologicalgrowth in the child. To this list of risks must beadded changes in the historical supports for familiesin a given society. The importance of this added levelof complexity was emphasized when we examinedFig 1. Multiple risk by 4-year mental health.

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secular trends in the economic well-being of familiesin the United States.

At 4 years, we had divided the sample into high-,medium-, and low-risk groups, based on the numberof cumulative risks: 0 or 1 in the low-risk group, 2 or3 in the medium-risk group, and 4 or more in thehigh-risk group. We found that 22% of the high-riskgroup had IQs ,85, whereas none in the low-risksample did. Conversely, 59% of the low-risk grouphad IQs .115 but only 4% of the high-risk sampledid.

After the 13-year assessment, we made the samebreakdown into high-, medium-, and low-riskgroups and examined the distribution of IQs withinrisk groups. Again we found a preponderance of lowIQ scores in the high-risk group and a preponder-ance of high IQ scores in the low-risk group, indicat-ing the continuing negative effects of an unfavorableenvironment. But strikingly, the number of childrenin the high-risk group with IQs ,85 had increasedfrom 22% to 46%, more than doubling. If our analysiswas restricted to the level of the child and family, wewould hypothesize that high-risk environments op-erate synergistically to worsen further the intellec-tual standing of these children during the periodfrom preschool to adolescence, placing them in adownward spiral of increasing incompetence.

An alternative hypothesis was that society waschanging during the 9 years between the RLS assess-ments. In a study completed by the US House ofRepresentatives Ways and Means Committee,17 itwas found that between 1973 and 1987, during thetime of this study, the average household income ofthe poorest fifth of Americans fell 12%, whereas theincome of the richest fifth increased 24%. Elder4 hasmade a strong case for attending to major changes insociety as determinants of the life course for growingchildren. His work centered on the Great Depressionof the 1930s. Similar effects seem to be apparent inour own times.

PROTECTIVE FACTORS AND THE SEARCH FORRESILIENCY

When studies are successful in identifying protec-tive factors, the issue is raised of identification on anindividual basis of resilient (or protected) individu-als. Ideally, one would like to identify a substantialsubset of children who, by any measure of compe-tence, were doing better than average, despite theadversity they faced in daily life. We selected a high-risk subsample of children who had four or moreenvironmental risks to determine the characteristicsof those who were doing better than expected. Only3 of the 50 high-risk children were above the totalsample mean on our 13-year child outcome mea-sures; but all 3 also had improved in their risk status.They had been in the highest risk category at 4 yearsof age, but by 13 years they were doing better. Thus,it is unclear whether the more favorable outcomes inthese children were attributable to protective factorsor to a lessening of risk.

When we examined the entire RLS sample to seewhat the consequences were for children movingfrom high (four or more) to low (0 or one) environ-

mental risk (or from low to high risk), we foundstriking effects. The group that changed from highrisk at 4 years to low risk at 13 years improved inmental health. In contrast, the group that changedfrom low risk at 4 years to high risk at 13 yearsshowed a decline in mental health. These findingsmake a strong case for the powerful effects of envi-ronmental risks on the children. Unfortunately, suchchanges in number of risk factors is not common. Wediscussed above the stability of risk factors fromearly childhood to adolescence. Only 1 child was inthe group that went from high to low risk, and therewas only 1 child in the group that went from low tohigh risk. Stability rather than change appeared to bethe rule.

There are many who argue that children do poorlyin conditions of poverty because they dont haveindividual characteristics that would promoteresilience, overcome challenge, and eventuate inproductive work and family life. By identifying char-acteristics of children who achieve despite adversecircumstances, some people hope that we could in-still those characteristics in other children to helpthem overcome environmental adversity. In contrast,others hold the position that environmental risks areso pervasive that opportunities do not exist for pos-itive development, even if the child does have excel-lent coping skills. Is it possible that despite socialadversity, children with high levels of personal re-sources are able to overcome minimal resources athome and in the community to reach levels ofachievement comparable with children from morehighly advantaged social strata?

Thus far, the presentation of our data has focusedon issues of environmental adversity and neglectedindividual factors that may permit children to over-come disadvantage. At this point, we can turn to anexamination of individual factors in the child, includ-ing emotional behavior during infancy. From theRochester data collected during the first year of life,we created a multiple competence score for eachchild during infancy that included a number of emo-tional indices. The infant risk score included 12factorsBrazelton neonatal test scores, easy tem-perament scores, and Bayley Infant Behavior Ratingscores. We then divided the sample into low-, medi-um-, and high-competence groups of infants andexamined as outcomes the 4-year IQ and socialemotional functioning scores noted previously.

There was no relation between infant emotionscores and 4-year mental health, especially whencompared with the effects of the contemporaneousinfant environmental multirisk scores describedabove (Fig 2). However, there is a general feeling thatinfant developmental scales may be weak predictors,because they assess different processes than are cap-tured by later mental health and personality assess-ments. Perhaps if we move up the age scale, we candetermine whether characteristics of these childrenat 4 years of age contribute to adolescent achieve-ments at our 18-year assessment. We divided the4-year-olds into high and low mental health groups.We then compared these groups on how they did at18 years on their mental health assessment (Fig 3).


Although as a group, the high mental health4-year-olds were doing better at 18 years than werethe low mental health group, when we controlled forenvironmental risk, the differences between childrenwith high and low levels were small compared withthe differences in performance between children inhigh- and low-risk social environments. Moreover, ineach case, high competent children in high-risk en-vironments did worse than low competent childrenin low-risk environments.

Perhaps at 4 years, mental health still is tooephemeral to resist the negative consequences of ad-verse social circumstance. Would competent childrenat 13 years succeed where competent children at 4years had failed? How would they measure at our18-year assessments of mental health? To find out,we divided the sample of children into high and lowmental health groups based on their assessments at13 years of age and examined their 18-year behavior(Fig 4).

Again, in each case controlled for environmentalrisk, we found that the highly competent children inpersonality or intelligence do far less well than wewould have expected. Those groups of children withearlier high levels of competence living in conditionsof high environmental risk did worse than similargroups in low-risk conditions, but even more to thepoint, did worse than low competent children inlow-risk environments. The negative effects of a dis-advantaged environment seem to be more powerfulcontributors to the emotional health of the child atevery age than the previous personality characteris-tics of the child.

SUMMARYOur findings from the RLS reveal that single en-

vironmental or child risk factors alone may havestatistically significant effects on emotional develop-ment, but these differences are small in comparisonwith the effects of the accumulation of multiple neg-ative influences that characterize high-risk groups.There are many successful adults who were raised inpoverty and unsuccessful adults who were raised inaffluence. There are many healthy and happy adultswho come from broken homes, and there are manyunhappy adults who were raised by two parents.

The important implication is that a focus on singlecharacteristics of individuals (like resourcefulness orintelligence) or families (like welfare or marital sta-tus) can never explain more than a small proportionof variance in normal behavioral development in-volving a wide variety of environments. But majordifferences do emerge when comparisons are madebetween groups of children with many risk factorsand those with only a few. To truly appreciate thedeterminants of competency requires that attentionbe paid to a broad constellation of ecologic factors inwhich these individuals and families are embedded.

We have indicated that there are many environ-mental risk factors associated with poor develop-mental outcomes. Our analyses of the effects ofenvironmental risk on development have focused onthe negative aspect of each variable. This was inten-tional in that we were trying to find a way to identifythose infants who are likely to be the most troubledand truly in need of intervention. These risk factorscan be found in all socioeconomic strata, but are mostconcentrated in areas of poverty. There may be socialconsequences of this research if changes can be madein the number of risk factors experienced by families.In the natural course of time in the sample we stud-ied, there were few such changes. High-risk familiesremained high risk and low-risk families remainedlow risk.

In the introduction to this article, I contrasted aconcern with the current and future happiness ofinfants. The conclusion from our work is that thefuture happiness of children is related only mini-mally to their behavior during infancy. The currentand future social context is a major developmentaldeterminant with the power to foster or hinder lateremotional well-being. The study of the social ecologyof children must be a central concern of professionals

Fig 2. Relation of early social environmental risk to 4-year mentalhealth scores for high and low competence infants.

Fig 3. Relation of 4-year social environmental risk status to 4-yearmental health scores for high and low competence infants.

Fig 4. Relation of 13-year social environmental risk status to 18-year mental health scores for 13-year-olds in high and low mentalhealth groups.

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hoping to understand and promote the emotionaldevelopment of children.

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