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Sex and Aggression

In the book Connections Between Sexuality and Aggression (1998), Dolf Zillman wrote, "Aggression and sexuality are greatly interconnected, and the mechanisms of this interconnectedness and largely understood." They involve brain areas, chemicals, hormones, and behavioral connections.

Sex itself can be very aggressive. In many different mammalian species sexual encounters look like fights, sometimes accompanied by thrashing about, loud noises, and (in cats) mock biting, scratching, then a final act of pushing away that looks distinctly unfriendly.

However, after such displays, male and female cats such as lions remain in each other's proximity for multiple mat­ings. Evidently the act is not aversive to them.

Perhaps one reason sex and aggres­sion alternate so easily is that they are related by evolution and biology. Sometimes the same exact neurons are involved, as discovered by Dave Anderson at the California Institute of Technology. Goldhill (2016) reported:

Anderson has found that a tiny cluster of neurons (relative to the size of each animal's brain–so 10 neurons on either side of the fruit fly's brain, and 2,000 on either side of the mouse's brain) have a role in controlling both sexual and aggres­sive behaviors of males. He's made such discoveries by genetically targeting each neuron; with that level of precision, he can turn the neurons on and off.

Now he's working to establish whether it'd be possible for these clusters to prompt both sexual and aggressive behavior simultaneously, or whether it's an either/or mechanism.

Previous research suggests it is an either/or mechanism. The neurons activated during attack are inhibited during mating, preventing interference during mating (Lin et al., 2011).

What did Anderson discover about neurons devoted to sex and aggression?

In primates as well, aggression and sex­uality are linked. Winning a fight increas­es levels of the sex hormone, testost­erone, in all primate species. Something similar was documented in human tennis players:

"After matches, mean testosterone rose for winners relative to losers, especially for winners with very positive moods after their victories and who evaluated their own performance highly. Winners with rising testosterone had higher testosterone before their next match, in contrast to losers with falling testosterone, who had lower testosterone before their next match." (Booth, Shelley, Mazur, Tharp, and Kittok, 1989).

What happened to men who won tennis matches?

This makes evolutionary sense. The male winner of a fight-like competition benefits in reproductive success: he has more access to females. If he has higher levels male hormone as well, that fosters great­er degrees of sexual activity as well as aggression.

Phenylethylamine, the chemical involved in limerence, the falling-in-love phenom­enon (as well as patting friendly dogs) is an endogenous amphetamine. Clearly it does not necessarily trigger aggres­sion, but it might trigger approach which is related.

Amphetamines cause a "staggering increase in aggression" in non-human primates (Antelman, Eichler, Black, and Kocan, 1980). If sexual arousal pro­duces amphetamine-like chemicals, this may explain why males and female humans are more willing to give shocks to an experimental confederate, after reading erotic passages (Jaffe, Mala­muth, Feingold, and Feshbach, 1974).

How do hormones and chemicals link sex and aggression?

Not all primates are aggressive. In at least one species, aggression takes second place to sex. The bonobo (bo-NO-bo) is the human's closest relative among primates.

Among bonobos, sex is frequent, brief, bisexual, and promiscuous. Almost anything exciting (such as anticipated food) causes bonobos to initiate sexual contacts with one another. This makes bonobos unlike other types of chimp­anzees, who fight more and have sex less.

Bonobos appear to divert aggressive impulses into sexual behavior, and they often initiate a sexual encounter to reconcile with each other after an aggressive display. A female bonobo might walk up to a dominant male who is hoarding food, display sexually, partici­pate in intercourse for up to 15 seconds, take some food, and walk away.

What are some patterns of sexual behavior among the bonobos?

Female genital-to-genital contacts are equally common. It looks like a hug and typically lasts only a few seconds. Among bonobos, sex is used as a pacifier, a form of reassurance, and a sign of friendship.

Psychological Sadism in Immature Relationships

Among humans, aggression is some­times diverted into sexual behavior. This is a well-known pattern in certain dys­functional (abnormal or poorly function­ing) relationships. Fighting or arguments are part of a routine that ends in "kissing and making up."

Fromm (1956) described a pattern of psychological sadism that appears in many immature relationships. The masochist in such a relationship is a person who takes a passive or submissive role.

This is not to be confused with sexual sadism, the paraphilia in which people get a thrill out of hurting somebody, or pretending to. As Fromm described it, psychological sadism was an oppres­sive, dominating approach to a relation­ship. It need not involve actual violence, although it often escalates into episodes of violence.

Fromm describes a psychological sadist as one who commands, exploits, hurts and humiliates the partner. A psycholog­ical sadist often shows the world a hard exterior. If male, he is likely to be macho, physically impressive, or just tough. Ironically, this may indicate an insecure streak.

The family background of the psycholog­ical sadist often includes alcoholism, divorce, or constant fights between family members. One might speculate that this creates a compen­sating drive to be strong and avoid being vulnerable or abandoned.

In our culture, the psychological sadist in a lopsided relationship is typically (but not always) a male. He is likely to believe in traditional values and male superiority over women.

What are typical characteristics of male who assumes a sadist role?

In our culture the masochist is usually but not always female. She simply allows herself to be dominated. The book Sweet Suffering (1984) by psychoanalyst Natalie Shainess portrayed the masochistic role among females as very common, almost inevitable in human relationships.

What did Shainess say about women's suffering? What was Caplan's reaction?

Paula Caplan, who authored The Myth of Women's Masochism (1984) responded that this view "does women a profound disservice." She argued that rationaliza­tion or acceptance of the masochistic role is an undesirable product of social­ization, family upbringing and cultural role models in a male-dominated society.

"Once violence starts, it just goes from bad to worse," warns Mary Haviland, a counselor for battered women in Brooklyn. "Violence begets violence. It always escalates. And if you start your dating life by experiencing and accepting violence, the chances for experiencing terrible violence when you're older are great."

A Common Pattern

Fromm was writing about psychological sadists and masochists in 1956, but he could have been referring to some of today's college students. Immature relationships often fall into a pattern resembling Fromm's psychological sadism. Here is a composite built up from about a dozen essays turned in by students in response to Fromm's description of psychological sadism:

The relationship starts out fine. The couple presents their best faces to each other. They fall in love and they are on cloud nine.

After the couple dates steadily for a while, the thrill starts to wear off and simultaneously the sadist (usually the male) starts to become more domi­neering. The domination is flattering at first but soon becomes excessive.

He attempts to pick his girlfriend's make-up, select hobbies for her, even pick her friends. He is displeased if she sees old friends.

A crisis occurs. He accuses her of flirting with other men, or he picks a fight with someone at the party. Perhaps he gets rough, speaks harsh words, or strikes her. She is shocked.

She gives him an ultimatum: if he ever does such a thing again, they are through! He assures her it won't happen again.

But it does happen again, because it seems to be out of his control. There is another act of violence or humiliation. True to her word, she breaks up with him.

A spectacular display ensues. The tough macho man breaks down and reveals the little boy inside. Tears flow. He promises he will never do it again, if she will agree to take him back.

Sometimes there are many cycles of forgiveness followed by repeated acts of violence or humiliation.

Eventually the person on the receiving end of the punishment sees the pattern and realizes it will not change. But breaking up with an insecure, bullying type of person is not easy!

By this time he may have learned that his best tactic is stubborn persistence. He refuses to take No for an answer.

If sheer stubbornness doesn't work, he goes to pieces, threatens suicide, or threatens to kill her. He might telephone many times a day, or sabotage her car, or wait in the bushes by the place where she leaves, ready to jump out and continue the arguments about why she should come back to him. Sometimes it is months, even years, before the harassment stops.

What pattern often occurs in some immature relationships?

This pattern was described by students as typical of some (certainly not all) first relationships in high school and some­times in college. The pattern seems especially likely to occur if the male comes from a troubled or broken home, perhaps because more appropriate patterns of interaction are not modeled by the parents.

The Jealous Male

A common element in many troubled male/female relationships is the jealous male. A male who attempts to dominate a relationship, playing what Fromm called the sadistic role, shows exagger­ated jealousy in protecting his "property."

In research that is old but probably still valid because it describes a primitive pattern, White (1981) found extreme jealousy correlated with low self-esteem, overdependence on the partner, low educational background, and unhappi­ness. Jealous males typically believed in the double standard.

They felt it was acceptable, even expected, that males would cheat on their girlfriends and, later, on their wives. But women must remain faithful.

So the jealous male cheats, and that probably explains why he is jealous. This is a classic example of the Freudian defense mechanism called projection.

What are typical characteristics of a jealous male? What is the double standard?

Projection occurs when a person sees his or her own unpleasant qualities in someone else. The jealous male accuses his girlfriend of flirting with other men or giving them subtle "come ons" if she looks in their direction. In reality, such suspicions reveal the male's guilt and his assumption that his girlfriend's mind works the same way his does.

Luckily, humans can think about their behavior and change it if they really want to. One student claimed that simply pointing out the "guilt projection" pattern to her boyfriend made a difference.

When is projection revealing?

One night my boyfriend and I got into a major argument over a guy that he thought I was flirting with. I remembered the chapter on love and explained to him that he might be feeling guilty about something he had done, and that he was taking it out on me. I think it really got to him because he apologized for 3 days and he now thinks twice before getting angry with me for no reason. [Author's files]


Anderson, D. (2012) Optogenetics, sex, and violence in the brain: Implications for psychiatry. Biological Psychiatry, 71, 1081-1089. doi:10.1016/j.biopsych.2011.11.012

Antelman, S. M., Eichler, A. J., Black, C. A., & Kocan, D. (1980). Interchangeability of stress and amphetamine in sensitization. Science, 207, 329-331.

Booth, A., Shelley, G., Mazur, A., Tharp, G., & Kittok, R. (1989) Testosterone, and winning and losing in human competition. Human Behaviour, 23, 556-571.

Caplan, P. J. (1984, September). Women in distress. Psychology Today, pp.10-11.

Fromm, E. (1956). The Art of Loving. New York: Harper.

Goldhill, O. (2016, May 7) There's a neurological explanation for the link between sex and violence. Quartz. Retrieved from:

Jaffe, Y., Malamuth, N., Feingold, J., & Feshbach, S. (1974) Sexual arousal and behavioral aggression. Journal of Personality and Social Psychology, 30, 759-764.

Lin, D., Boyle, M. P., Dollar, P., Lee, H., Lien, E. S., Perona, P., & Anderson, D. (2011) Functional identification of an aggression locus in the mouse hypothalamus. Nature, 470, 221-216. doi:10.1038/nature09736

Shainess, N. (1984). Sweet suffering: Woman as victim. Indianapolis: Bobbs-Merrill.

White, G. L. (1981) Some correlates of romantic jealousy. Journal of Personality, 49, 129-145. doi:10.1111/j.1467-6494.1981.tb00733.x

Zillman, D. (1998) Connections Between Sexuality and Aggression. Mahwah, NJ: Lawrence Erlbaum.

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