KELSEY GROSSMANLAURA JIMENEZ

COUSINS, A. J., FUGERE, M. A., & FRANKLIN M. (2009), DIGIT RATIO (2D:4D), MATE GUARDING, AND PHYSICAL

AGGRESSION IN DATING COUPLES. PERSONALITY AND INDIVIDUAL DIFFERENCES, 46, 7, 709-713.

Digit ratio (2D:4D), mate guarding, and physical aggression in dating

couples

Introduction

Mate guarding: a way for a male to assure that partner remains faithful and doesn’t succumb to infidelity Makes sure male doesn’t spend energy raising a child that isn’t his

own Consists of monopolizing one’s mate and discouraging potential

threats from making a move on his mate 2D:4D: digital ratio which indicates the levels of testosterone in

the body Higher levels of testosterone in utero are associated with lower digit

ratio and with aggressive behavior Is an unusual trait because it doesn’t change as much across the

lifespan as do secondary sex traits Aggressive behaviors are often associated with mate guarding

Studies that show a relationship between aggression and 2D:4D indicate that low 2D:4D women show more reactive aggression (anger in response to frustration and being provoked) and indirect aggression (sneaky, manipulative aggression, for example; spreading a rumor)

Hypothesis

Men with lower 2D:4D will: 1. Mate guard more than higher 2D:4D men 2. Make more intrasexual threats than men with higher 2D:4D 3. Be more physically aggressive toward male competitors

than men with higher 2D:4D 4. Be more physically aggressive toward their partner than

higher 2D:4D men 5. Be more physically aggressive when their partner cheated

Also, 6. Women will resist mate guarding more when they cheated 7. Women will resist mate guarding more when their partner

has a higher 2D:4D, due to lower costs to her 8. Women’s 2D:4D will not be associated with any of the

behaviors described above

Methods

Participants 101 heterosexual dating couples

At least one member of the pair was enrolled in an Introductory Psych class Mean relationship length was 18 months

SD = 16.24 Mean female age was 20

SD = 3.09 Mean male age was 21

SD = 3.85 Women demographics

55% white 34% Hispanic 3% Asian 7% other

Men demographics 56% white 36% Hispanic 2% Asian 4% other

Materials and Procedure

First all participants had their 2D:4D levels evaluated by measuring each side of the index finger and the ring finger on the right hand of each participant twice. Measurements were averaged in order to create the ratio; index finger (2D) to ring

finger (4D) Then a 42 item male guarding scale with seven subscales was administered

Asked to rate whether each behavior listed had occurred during the past 6 months From 0 (never) to 4 (very often) Subscales included:

Vigilance Protection Monopolization Possessiveness Intrasexual threats Intrasexual physical aggression Threats and aggression toward partner

Also administered a scale which measured resistance behaviors 27 items; questions included, “I hid stuff from my girlfriend so she wouldn’t find it” Each individual rated their resistance to specific behaviors during past 6 months on a

0 to 4 scale Higher scores indicate more resistance to mate guarding

Lastly, each participant was asked to state whether they’d ever cheated on their current partner 84% Women (N = 84) said they had never cheated on their partner 16% Women (N = 16) said they had cheated 87% Men (N = 87) said they had never cheated on their partner 13% Men (N = 14) said they had cheated

Results

2 x 2 ANOVA Contrary to hypotheses:

There was no relationship between men’s 2D:4D and overall levels of self-reported mate guarding

There was no relationship between 2D:4D and intrasexual physical aggression

Consistent with hypotheses: Men with a lower 2D:4D were more likely to state that they made

intrasexual threats Men with more masculine 2D:4D were more threatening and

physically aggressive toward their partners Men were more threatening and physically aggressive when their

partner stated she cheated Women were more resistant to mate guarding when they cheated

on their current partner

Discussion

Overall mate guarding was not significantly correlated with 2D:4D

Low 2D:4D men were more threatening and physically aggressive toward their partners than high 2D:4D men

2D:4D was not correlated with behavioral aggression in women

Women were more resistant to their partner’s mate guarding when he had high 2D:4D

When the costs of resistance become too high, women may tolerate mate guarding

Critical Review

Limitations: Unable to say whether participants’ 2D:4D is

related to their current circulating hormone levels

Unable to say whether these results would differ for people who have children

Strengths: The use of couples in romantic relationships

Uncommon and allows for assessment of interactions between partners

Linking two areas of research; 2D:4D and mate guarding

Quiz1. Which level of 2D:4D indicates a higher tendency towards aggressive

behavior and mate guarding? A. Low 2D:4D B. High 2D:4D C. Both A and B

2. The woman participants in the study reported cheating more than the male participants (T/F)

3. Women may allow mate guarding by men with low 2D:4D because… A. They respect them more than high 2D:4D B. They think low 2D:4D are sexier than high 2D:4D C. It is too costly to resist them

4. How many questionnaires did the participants completed? A. 1 B. 2 C. 4

5. 2D:4D was correlated with behavioral aggression in women (T/F)6. Men were more threatening and physically aggressive when their

partner stated she cheated (T/F)