Sex differences in antisocial behavior (part 2) intimate partner violence

Last week I introduced the Dunedin study a 30+ year look at the lives, behaviors and personalities of a group of New Zealanders born in 1972. We learned that a small percentage of males and females in the study population were responsible for a high percentage of the antisocial acts reported by the group. Next week, I will discuss the personalities and early histories of this group of people.

This week I want to tell you about the one exception to the observation that men were more antisocial than women. In the realm of intimate partner violence, women were as antisocial as men. Furthermore, a general tendency to be antisocial was found in both men and women who were violent toward their partners.

The results of the study support the contention that sociopathy leads to intimate partner violence.

At age 21 participants reported about partner violence over the past year (83%) or as part of their dating experience (8%). They were assessed by a structured interview that included questions about perpetration and victimization. The researchers also conducted identical interviews with partners of the study participants. They used the:
• Physical Abuse Scale- 13 items
— Physical twisted arm
— Pushed grabbed or shoved
— Slapped
— Physically forced sex
— Shake
— Throw
— Thrown object at
— Chocked or strangled
— Kicked, bit, hit with fist
— Hit with something
— Beat up
— Threaten with gun or knife
— Use of gun or knife

The study found that 8% of couples had clinical level of IPV. In the 30 cases that involved justice system, 80% of the abuse lead to injuries. Both male and female perpetrators were involved. Women with a history of conduct problems were more likely to become involved in a relationship with an abusive man; being involved with an abusive man contributed significantly to woman’s perpetration. However, even after controlling or partners’ physical abuse, women with a history of conduct problems were still likely to commit violence.

The researchers also found that these aspects of the antisocial propensity contributed to intimate partner aggression in both men and women:

— Approval of the use of violence
— Excessive jealousy and suspiciousness
— Intense and rapid negative emotions
— Poor self-control

They concluded, “Among men and women IPV perpetration is but another expression of an earlier-emerging antisocial propensity.”

There were other studies my class and I read that concluded men more frequently perpetrated domestic violence. The authors of these studies suggested that dominance motives on the part of men were important. My class and I then set about to search for other research regarding dominance motives and intimate partner violence. We found a paper that explains it all, Dominance and symmetry in partner violence by male and female university students in 32 nations by Murray A. Straus, Ph.D. of the Family Research Laboratory at the University of New Hampshire.

This paper addressed three questions:
1. Is partner violence primarily perpetrated by men, as compared to women, and as compared to both partners engaging in physical violence?
2. To what extent is dominance by the male partner associated with partner violence, as compared to dominance by the female partner?
3. In short is the risk factor male dominance or dominance by one partner, regardless of whether it is the male female partner?

Their first finding was that female university students around the world more frequently perpetrated partner violence, the gender gap was about 30%. They then set out to examine whether male or female dominance in the relationship was related to IPV.

Dominance by the partner who completed the survey was measured by the Dominance scale of the Personal and Relationships Profile. Examples of the items are “I generally have the final say when my partner and I disagree” and “My partner needs to remember that I am in charge.” The response categories are 1 = Strongly Disagree, 2 = Disagree, 3 = Agree, and 4 = Strongly Agree. The scale score is the mean of nine items.

The nation with the highest score for Dominance by male partners was Tanzania, which is also the least modernized of the 32 nations in this study. The four national settings which are the next most male dominant are Russia, Iran, Taiwan and mainland China. The national setting in which male students have the lowest average dominance score is Sweden, which is a nation that has led the way in steps to promote gender equality. The other four of the five least male dominant national settings are Netherlands, Canada, Switzerland, and Malta.

In relationships where only men were violent. Male dominance increased the odds of violence by 2.29. Each increase of one point on the four point Dominance scale increased the probability of violence by male students 2.29 times. Interestingly, of the other four variables in the Male-Only panel, only one—length of the relationship—is significantly related to Male-Only violence.

In relationships where only women were violent, male dominance increased the risk of Female-only violence by 1.96 times. Again for each one point increase in the male dominance scale Female —Only violence increased 1.96 times. The only other significant relationship in the Female-Only panel shows that the longer the relationship the higher the odds of Female-Only violence.

What about male dominance and bidirectional violence (relationships where both partners are violent)? First, dominance by the male partner is associated with a three-fold increase in the probability of both partners being violent. This is larger than the increase in the probability of Male-Only or Female-Only violence. That is, dominance by a male partner is more strongly associated with bidirectional violence than with Male-Only violence.

Now comes the most interesting part”¦ dominance by women. This is for all you great guys out there who know that women are not always sweet, lovely, submissive creatures. Female dominance was actually common in relationships around the world!

Overall, the Dominance scale scores are higher for women than for men in 24 of the 32 nations, and in all 12 of the nations with the lowest scores for male dominance. Although the differences are small, they are not consistent with the large body of evidence showing greater male power in intimate relationships in most societies. But keep in mind the subjects of this study were university men and women.

Female dominance as reported by women is associated with about a two and half times greater probability of the Male-Only pattern of IPV. The probability of Male-Only violence increases by 3% for each additional month the relationship has been in effect.

Female dominance is much more strongly linked to Female-Only violence than was shown for the relation of male dominance to Female-Only violence. That is, when there is dominance by either partner, it increases the odds of Female-Only violence, but the increase is much greater for female dominance.

Female dominance also increased bi-directional violence, but the effect of female dominance on the odds of bidirectional violence tends to be greater than the effect of male dominance. Age is related to a decrease in the odds of bidirectional violence, and the longer the relationship the greater the odds of bidirectional violence.

I think the research in IPV gives us very important messages about love and life. First sociopaths who are obsessed with power and dominance are not good relationship partners. Secondly, although the human dominance drive is there to energize us to compete and better ourselves, this drive if out of balance, can be very destructive.

What say you?