The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life

by Robert Trivers

  How can you know for sure that the child a woman carries is genetically your own? Of course, you can’t. Some men torture themselves over the possibilities, the hours when she was not around, phone calls with old friends, whatever. But I always believed the issue was overrated, because I did not believe it was possible for me to look at a child for long and not be able (without DNA tests) to know whether it was my own. There are enough dominant genetic markers in my lineage that the truth must be there in front of my eyes. If that is really true, then we are talking at worst about nine months or so of wasted investment, a trivial cost, put to a good social purpose. Let us put the matter behind us and go on with the rest of our lives. In other words, we need not spiral off into the fatal land of jealousy, but that is alas all too common, as the following suggests.

  MALE RESPONSE TO FEMALE INFIDELITY

  A man’s response to signs of his partner’s infidelity in an intimate relationship seems general the world over: anger and aggression, an attempt to suppress the behavior by threatening, beating, isolating, and sometimes murdering the woman. The result often is a thoroughly frightened and dominated woman, told that any attempt to flee will be met by murder, leading to a defensive form of imposed self-deception, where the woman often comes to believe her tormentor and blames herself. Genital cutting of women (to reduce desire), foot binding (to reduce mobility), and claustration (to isolate socially) all serve to reduce female choice in advance of temptation, though I doubt they are usually rationalized this way within the societies that practice them.

  The law is stacked as well. It was a historic and cross-cultural universal for “unauthorized” sexual contact with a married woman to be a crime (for both the man and the woman), with the husband as the victim. In some parts of the United States, the very sight of adultery was, until very recently, considered sufficient justification for murder—of either party—by the husband. What all this means is that extramarital sex or the mere suspicion of it can be very dangerous to the woman (and the other man). Very powerful selection pressures—murder and imprisonment, for example—may be associated with deception regarding extra-pair relations. My own (very limited) experience is that one can hardly deny from consciousness other ongoing relations, so that extra-pair relations inevitably involve conscious deception, and self-deception must at best serve self-confidence in the face of possible accusation.

  Consider homicide. In many American cities, sexual jealousy is the second or third leading cause of murders, and in many societies it is the first. In Detroit, one-third of all murders in 1972 were “crime specific” (as part of a robbery, for example), but of the remaining, fully one-fifth were due to sexual jealousy. The detailed breakdown is of some interest (total N = 58). Men were four times as likely as women to instigate jealous actions leading to murder. In roughly equal numbers, men killed their partner or the other male and were almost as often killed themselves by the woman (sometimes aided by a relative of hers). Two men murdered their unfaithful homosexual lovers—no problem of uncertain paternity there! When a partner was unfaithful, women were somewhat more successful, killing one of the adulterers in nine instances while being killed by the mate in only two.

  In Canada, 55 percent of all wife-beating court cases involve at least some jealousy. Men respond to possible infidelity with anger, drunkenness, threats, and sexual arousal. The last is a most interesting subtlety. In many species of more or less monogamous animals, the sight of one’s own female having sex is sexually arousing to the male. Even ducks being raped by groups of males are often re-raped by their mate immediately afterward, presumably to introduce sperm in competition with that just introduced. So it is a feature of male psychology that evidence or fantasies of mate involvement with others may be sexually arousing. I have never found the reverse to be true. Women respond to extra-pair copulations with tears, feigned indifference, and efforts to increase their attractiveness. Men get angry and drunk.

  Men are, of course, prone to self-deception in evaluating their partner’s extra-pair activities. The lower their self-image, the greater their expected suspicion, if not full-blown paranoia. The lower his intrinsic quality, the greater is her temptation. Given that he is of lower putative genetic quality, she may more easily dominate him, so that he may not dare voice his suspicions for fear of being dropped entirely. A second reason men may practice self-deception arises from their own guilt. Many times I have seen men accuse their innocent partners of exactly what they themselves are up to, another case of denial and projection, the accusations presumably serving mostly as camouflage.

  DECEIT AND A WOMAN ’S MONTHLY CYCLE

  A woman’s biology changes in very interesting ways during her monthly cycle, with many implications for deceit and self-deception. Women are more attractive at the time of ovulation—they appear to be physically more symmetrical and their waist/hip ratio is slightly more curvaceous. They also derogate the looks of other women more than at other times in the cycle. Are they (unconsciously) comparing other women to themselves and derogating other women because they themselves are relatively more attractive when ovulating, or are they adding a degree of derogation so as to accentuate their own superior appearance when it most matters? I would imagine the latter, but the evidence is not sufficient to say.

  Women appear to be more sexual in general at the time of ovulation but with a distinct bias toward more genetically attractive men and extra-pair sex. In several clubs in Vienna where partners were studied over many months, a woman was less likely to show up with her partner near her time of ovulation while displaying more skin (wearing less clothing). At time of ovulation, women’s preferences for men’s faces shift toward those that are relatively more masculine and symmetrical, signs of genetic quality but not paternal investment. (Women’s preference also shifts toward slightly darker men and less hairy ones.) If employed as a lap dancer and not on the pill, a woman earns 30 percent more per hour when ovulating than when not (excluding during menstruation, when she earns even less). If she is on the pill, then there are no differences in her earnings across the monthly cycle.

  Changes across the cycle can reflect underlying subtle genetic tensions between the sexes. A particularly striking result shows that the more a woman matches her partner’s genes at critical major histocompatability loci involved in defense against parasites—which is a disadvantage in that it lowers offspring survival—the less likely a woman is to have sex at ovulation, the more often she has (verbally) coerced sex, and the more often she fantasizes about sex with another man (including prior partners) while having sex. But twelve days later, when she is not ovulating, there is no effect of gene matching on her sexual behavior and fantasies (compared with women who do not match). Men show no effects of matching their partner on the major histocompatability loci at any time. They are out of the loop.

  So we expect more pressure on women to act deceptively at the time of ovulation. In this case, the woman engages in a voluntary, conscious kind of self-deception—temporary fantasy—that she is unlikely to wish to share with her partner. She may start developing a private life of fantasy that recurs each month, perhaps tempting her to more overt actions at this time in the future. In any case, a private life is carved off from her partner, acting over a few critical days every month. It would be most interesting to know whether some men notice that when their partner is most attractive to them, she is least sexually interested in them. And how do they respond, if at all?

  Smell is an important part of sex. A woman’s sense of smell is more acute than a man’s, and this is especially true at her time of ovulation, where her sensitivity to certain sex-related compounds may increase a hundredfold and her ability to discriminate men’s bodily symmetry based on smell hits a peak. I am often astonished at how naive young men are regarding the olfactory dimension of life. I hear the same story from students: “I was due to meet my girlfriend later but this woman was hot for me, so I enjoyed some sex, nothing special, nothing to detract from my lady, but as soo
n as I saw her, it was like she knew right away something was up.” I then ask these young men whether they had thought to bathe after having sex. No, hadn’t occurred to them—perhaps this was their problem. They were living in one olfactory world, their partner in another. Of course, there may be no escape—a good student of your behavior may ask you why you just bathed at this odd time of day.

  This difference in the olfactory dimension can be extended to many other aspects of mental life. Women are better at reading facial expressions, but men are better at picking out hostile images in a crowd. Sounds may be processed in different sections of the two brains, and it is a remarkable fact that in a variety of mental tasks, women’s brains tend to act more symmetrically than men’s—that is, the two hemispheres are used more equally in solving a given task. Since symmetry is so often an advantage in life and mental life in particular—for example, depth perception and location in vision and hearing both result from the use of bilateral information simultaneously—one’s initial assumption must be that women thereby gain an advantage over men. The corpus callosum connecting the brain’s two hemispheres in women is relatively larger than in men, meaning information is more easily shared and symmetrical functioning more likely.

  MEN’S SELF-DECEIT ABOUT FEMALE INTEREST

  Several lines of evidence suggest that men deceive themselves about women’s sexual interest in them. Women report that men are more likely to believe that a woman has greater sexual interest in him than she really has, rather than less. By contrast, women show no bias in how they rate men’s interest in them (high or low). Experimental evidence provides congruent evidence. By logic, men may gain more from such a perceptual bias than do women. They will catch more women with actual interest while making more false projections in the process. Assuming there is not much cost to the errors (the woman turns him down, he departs), the bias will give a net benefit. Of course, a reputation for overeagerness could add to the cost. This might result in a self-deceived bias toward greater interest while simultaneously thinking of oneself as “cool”—relatively restrained toward others.

  There is evidence that women’s behavior may heighten male illusion of female interest. When in experiments the two sexes are introduced for the first time for a ten-minute videotaped session together, female courtship behavior is higher in the first minute (e.g., nodding) but unassociated with any actual interest. Such behavior is associated with interest only in the later stages (four to ten minutes), so that women appear to display interest before they develop it. This will give men the illusion of interest before it develops and, indeed, female nodding behavior in the first minute predicts male talking in the later stages.

  MALE DENIAL OF HOMOSEXUAL TENDENCIES

  It has long been argued that denying one’s homosexual impulses will cause one to project them onto others. It is as if we detect some homosexual content in our immediate world, and denying our own portion, we go looking for it in others. That this homosexual denial can lead to homosexual aggression is not surprising, because someone else’s homosexual content may be a direct threat to our own hidden identity—do we respond, in spite of ourselves, to an attractive young man with a bouffant hairdo and a woman’s perfume? We had better attack him before anyone notices our arousal. This is also sometimes called a reaction-formation. What is attractive to the self but unacceptable is disdained and denied for self but attacked aggressively when seen in others. A man thereby supports his image of heterosexuality by attacking homosexuals.

  Recent work supports this kind of dynamic. In the United States, A-1 heterosexual men by Kinsey criteria—no homosexual behavior, no homosexual thoughts or feelings (or so they say)—were divided into those who were relatively homophobic, that is, upset and hostile toward homosexuals, and those who were relatively relaxed and unconcerned.

  The fun part came when these men got to watch three six-minute erotic movies—a man and a woman making love, two women, and two men—while a plethysmograph attached to the base of each penis measured penile circumference very precisely. In addition, after the film, each man was asked how erect and how sexually aroused he had been. An interesting result emerged. Relatively homophobic and non-homophobic men responded similarly to the heterosexual and lesbian films, strong arousal to each, but more so for the heterosexual. It was only the male homosexual film that revealed a divergence. Non-homophobic men showed a small but insignificant increase in penis size, but homophobic men showed steady penis size growth throughout, reaching two-thirds the level seen in their response to the two women. Interviews afterward showed that everyone had an accurate view of the degree of his penile enlargement and arousal (which were highly correlated), except for the homophobic men viewing the male-homosexual scenario. They denied their tumescence and arousal. Whether they were actually conscious of this is unknown.

  IS SELF-DECEPTION GOOD OR BAD FOR MARRIAGE?

  There are two extreme forms of deception in a relationship where sex and love are concerned. The sex is great and you have to fake the love, or the love is real but you have to fake the sex. By the time we are thirty, we have all been in these situations. When we have to fake the sex, we often invoke fantasy, a prior partner, an imagined partner, an imagined sexual act. Whatever gets us off. Note that these relations are especially dangerous to the partner. If the partner is unaware of your own true reactions, he or she will be unprepared for the betrayal that so likely awaits. On the other side, it may be much harder to fake love when there is strong sexual interest. Low-love relationships are apt to be more volatile, open hostility coexisting with passionate sex.

  The simple answer to the question about the effect of self-deception in a marriage is that it depends on the kind of self-deception. Self-deception of a positive, couple-reinforcing form appears to be beneficial, while self-deception associated with resolution of one’s own cognitive dissonance in the conventional self-serving ways appears to have the opposite effect—over-affirmation versus distancing. The aphorism that you should go into marriage with both eyes open and, once in it, keep one eye shut captures part of the reality. When you are deciding whether to commit, weigh costs and benefits equally; when you have committed, try to be positive and not dwell on every little negative detail.

  Consider first the positive form of self-deception. Couples last longer if they tend to overrate each other compared to the other’s self-evaluation. This has an appealingly romantic ring—“I love you, darling, more than you love yourself, and thereby uplift you.” Effects work on both sides. The more you overrate the other, the longer you stay together, and vice versa. Assuming long life together is a benefit, over-valuation is beneficial.

  People have a bias toward seeing improvement in the relationship over time even if this is achieved by exaggerating how bad the past was (compared to evaluations of the present). Once the past is misremembered, the memory of progress is established and relationships with greater memories of improvement last longer. It is important to emphasize that we can’t discriminate cause and effect. Self-deception may improve relationship satisfaction and duration, or it may accompany other factors that do. Perhaps success breeds self-deception (of the positive sort).

  Evidence suggests that marital satisfaction declines linearly over time, but people have a biased memory—they remember early declines in satisfaction but more recent increases that offset the early decreases. In one study, both spouses reported steady increases in relationship satisfaction over two and a half years while none could be detected. By the end of the time, though, memories were readjusted so as to remember no improvement in the more distant past, only in the more recent.

  In contrast, processes of self-justification within individuals make unity between the two more difficult so that, in the extreme, self-justification may be seen as an “assassin” of marriage. That is, active processes of self-justification appear to work against marital unity in a major way. Again, we do not know cause and effect. Is self-deception causing the disruption, or only facilitating it?
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  What we do know is that patterns of self-justification can be diagnostic. In trying to predict which couples would stay together three years later, scientists enjoyed surprising success based on studying the interaction between the two people during recorded sessions. Those who rewrote history in a more thoroughly negative way were predicted to break up. On this basis alone, the scientists correctly predicted all seven marital breakups, while incorrectly predicting three breakups that did not occur. They correctly predicted the other forty non-breakups, for a remarkable overall correct prediction rate of 94 percent. Though none discussed separation, some couples already talked as if they had forgotten why they married in the first place and were deep into processes of self-justification that appeared to function to reduce the dissonance of being in a bad marriage (while, of course, doing nothing to repair it). Other students of marriage claim to notice that when the ratio of positive to negative acts toward the partner drops below 5:1, the marriage is in trouble.

  THE APPEAL AND DANGER OF FANTASY

  Fantasy is an inviting and treacherous activity. It is deeply rooted in our biology. From our earliest years, we practice it spontaneously, with great pleasure, and it is easily encouraged by others. We create an artificial world and then choose to live in it. The fantasy typically replaces reality in a positive way—things would be better if the fantasy were true. For example, our five years of 24/7 work in the laboratory is, in fact, Nobel-quality work. As we do it, we can enjoy the return benefits sure to come our way later. Short of inducing fraud on our part, the fantasy may, in fact, improve the quality of our work. What the actual trade-off in additional fantasy-fueled labor and output is really worth, measured in other lost opportunities, is another matter, especially as the fantasy fails to pan out.