Some people consider themselves the jealous types. Others claim they don’t have it in them. Wherever you think you fall on this issue, research says we are all jealous at some level. More importantly, the jealousy we feel in our relationships have an evolutionary purpose. Even if we fancy ourselves modern and in control of our animal instincts, when it comes to jealousy, we haven’t changed all that much.
You wrote about the evolutionary theory of stalking earlier this year, I was surprised to learn that even stalking has a function?
“An astonishingly large number of people are stalked at some point in their lives. Our studies point to roughly 60% of women and 40% of men. Most of these don’t elevate to the level of ‘criminal stalking,’ which typically requires inducing high levels of fear in the victim. We (my co-author Dr. Josh Duntley and I) have developed a functional theory of stalking. Most of its functions center on mating. One of the most common is a jilted romantic partner who “can’t let go.” Stalking serves the functions of interfering with the ex’s attempts to get romantically involved with others.
From an evolutionary perspective, even if stalking only ‘works’ some of the time in driving off a mating rival and reacquiring an ex-mate, it still influences reproduction. I think that stalking came out of, or got ‘exapted,’ from hunting adaptations. It’s a small step from stalking game animals to stalking humans.”
Aren’t you afraid your studies provide the perfect excuse for those who engage in stalking?
“Criminal stalking is a crime, and finding that it has an evolved function in no way excuses stalkers. Indeed, understanding that men might have evolved proclivities to stalk might warrant more severe penalties in an attempt to deter what they might do more frequently without those penalties. More generally, finding that a behavioral syndrome has an evolved function does not speak to issues of ‘excuse’ or ‘responsibility,’ any more than finding that rape or murder caused by bad parenting, poverty, or “culture” excuses those crimes. Identifying the causes of our psychological circuits is a scientific enterprise. Deciding what to do about those circuits is a matter of values. In general, we don’t want people to stalk, rape, or murder, so we have developed laws against them, and hired a professional police force to enforce them. I’ve never heard someone day that a stalker’s behavior should be ‘excused’ just because it has an evolved function.”
You argue that men and women have evolved long-term and short-term mating strategies. Are these adaptations subject to change, or do they remain the same over time?
“In our modern environment, both strategies get played out in some novel ways because of inventions such as internet dating, websites that cater to married people who want to have affairs, etc. But our fundamental strategies of human mating have not changed.”
“If a man is not jealous at all, women often interpret that as a sign that he doesn’t love her”
‘Why Jealousy Is As Necessary As Love and Sex,’ is the subtitle of your book ‘The Dangerous Passion.’ Why is it necessary?
“Jealousy has several important functions. It motivates ‘mate guarding,’ which is critical in long-term mateships. It motivates driving off rivals or what I call ‘mate poachers.’ But it also serves as a signal of love to the long-term mate, at least in cases of mild to moderate jealousy. If a man is not jealous at all, women often interpret that as a sign that he doesn’t love her or is not sufficiently committed to her.”
Some men already get jealous when their girlfriends talk to other men, while others might be ok with their girlfriends kissing other guys. Is it overall universal how people react when it comes to being jealous, or does this depend on culture?
“There are universal aspects of jealousy and culture-specific aspects of jealousy. In general, men in all cultures have the evolved jealousy circuit, and it serves the functions we already discussed. There is some cultural specificity to jealousy. For example, in some cultures, men will get jealous if another man sees his wife’s face. Veils and burkas are often used in those cultures. I focus more heavily on the universal components, because those have been woefully neglected by scientists throughout the past century, but I do discuss the culturally-specific components where there is good evidence for them.”
“Roughly 90% of open relationships fail, or end up dissolving”
What about open relationships? Polyamorous couples tend to say they aren’t jealous; what happens to them in the long term as compared to those who say they are jealous?
Roughly 90% of open relationships fail, or end up dissolving. Most people aren’t psychologically built to having their partner having sex with others. Although even here, there’s gender difference. Most open relationships are initiated by men who want to satisfy their evolved desire for sexual variety. Some women ‘go along’ with the open relationship not necessarily because they want to sleep with other men, but rather in an effort to hold on to the mate they do have by letting him satisfy his desires. Historically and cross-culturally, polygyny – men having multiple wives – is far more common than polyandry – women having multiple husbands In fact, 83% of all cultures have been polygynous, whereas less than 1% have been polyandrous. Modern open relationships mimic a polygynous circumstance. Of course, there are some exceptions, or individual differences. A minority of women really do want to sleep with multiple men in open relationships; but most prefer the commitment of one man.”
“Mate poachers are always lurking and waiting for an opening”
Are we in an evolutionary danger if suddenly, people get less jealous?
“I don’t see that happening. We have evolved jealousy circuits that continue to serve their evolved functions. Mate guarding will always be necessary in long-term mateships since infidelity is always possible, and mate poachers are always lurking and waiting for an opening.”
One of the big arguments regarding love is that it is a construct based on movies, popular culture or a side effect of capitalism. In your research it seems you don’t agree at all. Does love exist for a reason?
“Love, like jealousy, is an evolved emotion. It tends to emerge primarily in the context of long-term mateships, and its primary function is commitment. Humans differ from our closest primate relatives, the chimps, in having long-term mating relationships; it’s actually pretty rare in the animal kingdom. Love evolved as a commitment device to increase the odds that the couple would stay together, at least long enough to ensure the survival of their children. Of course, people fall out of love, get divorced, and re-mate. But without love, long-term mateships would be far more tenuous or fragile.”
David Buss, professor of psychology at the University of Texas. Head of the Individual Differences and Evolutionary Psychology Area and supervisor of the evolutionary psychology lab. His book on the theme of jealousy is The Dangerous Passion: Why Jealousy is as Necessary as Love and Sex, was published in February of 2010.
Duntley, J., & Buss, D. (2010). The Evolution of Stalking Sex Roles, 66 (5-6), 311-327 DOI: 10.1007/s11199-010-9832-0