The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life
By Robert Trivers
(Basic Books, 397 pp., $28) 

ARISTOTLE WAS a cynic. Sure, the Bible exhorts to “Love thy neighbor as thyself,” but he knew better. “The friendly feelings that we bear for another,” instructed his Ethics, “have arisen from the friendly feelings that we bear for ourselves.”

Two thousand years later, in 1739, Hume spelled out what the pagan thinker intuited: “I learn to do service to another, without bearing him any real kindness; because I foresee, that he will return my service, in expectation of another of the same kind.” Hume’s Edinburgh neighbor, Adam Smith, penned an often quoted phrase in this vein in The Wealth of Nations: “It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own interest. Nobody but a beggar chooses to depend chiefly on the benevolence of his fellow citizens.”

Self-love makes the world go round. But, alongside cooperation, could self-love give birth to deception? Could the imperative of self-regard be so great, in fact, as to lead to self-deceit? In his new book, Robert Trivers, a master of evolutionary thought, roams from stick insects and brain magnets to plane crashes and Israeli-Palestinian wars in service of a corollary to Aristotle’s hard-boiled thesis. We humans deceive ourselves, Trivers argues. We do so often, and almost always the better to deceive others for our own personal gain. From misguided estimates of self-worth to false historical narratives of nations, the self-love that spins the world is itself fueled by self-deceit. And the price can be substantial.

Deception comes before self-deceit, and nature is riddled with it. A third of the 26,000 species of orchids propagate by deceiving pollinators into believing that they are enjoying a non-existent reward. Foraging octopi, who can change the color patterns on their skin at a rate of three times per minute for four hours at a time, bamboozle would-be predators into complete confusion. Male antelopes use warning barks to fool frightened females into sticking around rather than search for another mate. Cuckoos and cowbirds trick other species of birds into believing that the eggs they furtively lug into their nests are their own, carrying on carefree as the duped foster parents shoulder the burden of nestling and feeding the newborn hatchlings. The opossum feigns death, viral DNA hoodwinks bacterial (and every other kind of) DNA, the Viceroy dupes Monarch-wary would-be munchers.

Even the tiny blister beetle cuts an unassuming figure of deception: shortly after they hatch from their eggs, hundreds and sometimes thousands of baby beetles shimmy up a blade of grass to form a female digger-bee look-alike aggregate, emitting a female digger-bee pheromone, or perfume. When the innocent male bee comes along with thoughts of mating on its mind, it mounts the fake female and is soon covered with tiny cling-ons. These, in turn, jump ship again when the male encounters a true female bee, stowing away on her body into the bee burrow, where they will feed off the hard-won pollen she has collected and, eventually, her own larvae kin.

Between parasite and host, male and female, parent and offspring, predator and prey, plant and animal—deception is everywhere. But if nature is a picture of guile, what about us humans? Fake crying, pretend laughing, and temper tantrums in babies and children are evidence that deception starts early; the heartache of female and male promiscuity and the guilt-inducing manipulations of old age are signs that we never outgrow it. Trivers likes the sexy examples. Did you know that women’s waist/hip ratio is slightly more curvaceous and symmetrical when they are ovulating, and that in some studies they have been shown to be more likely to appear in a nightclub on these days without their partner and baring more skin? Did you know that homophobic males are more likely to be aroused by homosexual porn than non-homophobic heterosexual males? Or that in Jamaica to “cut a man a waistcoat” is to produce an extramarital offspring who looks just like the hoodwinked dad?

Deception is rife in humans for the same reason it is in nature: there are inbuilt clashes of interest, whether it be sexual strategy when it comes to females and males, parental investment when it comes to mothers and fathers, or resource allocation when it comes to parents and offspring. An expert in detecting conflict where others see harmony, Trivers worked out the evolutionary logic behind such relationships in the early 1970s, spawning entire fields in behavioral studies and genetics and giving rise to a number of predictions. One of the starkest of these was the idea that because fathers and mothers have different interests when it comes to the fetus (dad wants the baby bigger than mom does), identical genes on the chromosomes that they have each bequeathed will battle each other over control of embryonic growth. Sure enough, in the 1980s, biologists began to discover genes whose expression levels depended on from which parent they had come. And the gene knows where it came from, following the basic logic of genetic conflict Trivers described years before genomic imprinting was discovered.

Deception, to be truthful, is less of a mind-twister than self-deceit. Like Hume and Smith before him, Trivers understood that giving could serve one’s interests if the rewards of cooperation outweighed its costs. Using the logic of game theory, he showed that the principle of “you scratch my back and I’ll scratch yours” made evolutionary sense. Soon “reciprocal altruism” helped explain otherwise beguiling sacrificial behavior. But benevolence requires a strong sense of justice because a sense of justice is necessary to appreciate dishonesty: after all, in games of trust, especially with lag time, cheaters can wreak havoc. And so, over evolutionary time, an arms race honed in social mammals a growing intelligence. Trivers finds it ironic that “dishonesty has often been the file against which intellectual tools for truth have been sharpened.” But one of the outcomes of this Darwinian dynamic may have also been a genuine instinct for fairness, born of the need to distinguish trustworthy partners from charlatans.

But if evolution has done such a grand job of fine-tuning our senses in the service of detecting deceit, why does all the hard-won information that we extract from the world through our senses often become muddled and deformed in our brains? Why do we project our own traits onto others, repress true memories and invent false ones, lie to ourselves, rationalize immoral behavior, and generally deny inconvenient truths? Seventy percent of people rank themselves better-looking than average, according to a study cited by Trivers; 94 percent of academics (shocking!) think they are better than average, too. Why is this? The answer, Trivers would have us believe, is that the possibility of deceit raises the probability of ever more subtle mechanisms for spotting deceit, which in turn raises the probability of mechanisms for self-deceit. Trick yourself to trick another: what better way to conceal the truth? Self-deception is not a defensive measure meant only to make us feel better; it is a weapon instilled in us by natural selection to help deceive others for our own good.


SELF-DECEPTION is everywhere. There is rampant self-inflation—80 percent of school children, to provide another example, place themselves in the top half of students in leadership ability—but there are other kinds, too. “Confirmation bias” is one: we are all much more likely to seize upon facts that chime with our views and disregard—to the point of not seeing them—those that challenge them. Forms of self-deception occur also in situations of “us” and “them”: randomly divide a room of people into two groups, say “Reds” and “Blues,” and see how quickly bad traits are generalized to the out-group while good traits are imputed to the “ins.” If a “Red” steps on your “Blue” toes, for example, you are more likely to say “he is an inconsiderate person,” whereas if it was a fellow teammate you would simply report that “he stepped on my toes.”

False personal narratives are another example. For years Joseph Ellis, a historian of the American founding, told his students that he had been a war hero with the 101st Airborne Division in Vietnam when in fact he had been a graduate student at Yale and then a professor of history at West Point. Ellis was caught and apologized; but most of us constantly create fictional narratives about ourselves and think nothing of it. Indeed, much of self-deception is unconscious: with typical candor Trivers tells us how, while lecturing, he often steals chalk from himself only to discover later that he is out of chalk with which to teach.

Neurophysiology provides some fascinating evidence. Humans, it turns out, are more physiologically aroused by the sound of their own voice than that of others, but unconsciously so. In a classic experiment from the late 1970s, a group of people were each asked to read the same text. The recordings were chopped into short segments and a mosaic master tape was made with snippets from different voices. The participants were then hooked up to a machine measuring their galvanic skin response, which is normally twice as high for hearing your own voice than the voice of another. Then people were played the tape and asked to press a button when they heard their own voice. While some subjects denied their own voice and others projected it onto the voice of others (claiming that someone else was actually them), in all cases the skin had it right.

What is going on here? Information from either side of the brain reaches its target via a bridge, the corpus callosum, which connects left to right, the left hemisphere controlling the right side of the body and the right hemisphere, the left. Have you ever noticed that you are searching for an object—say, keys—and only spot it in your left visual field when you actually say the word “keys” aloud? Presumably, information is not being freely shared between the two sides of the brain across the corpus callosum, but when the right brain hears the object of desire being named, suddenly the left visual field and tactile side are awakened. Trivers believes this is related to self-deception. As is often the case, his evidence stems from his own experience (a trait he shares, by the way, with Darwin): Trivers has noticed that “inadvertent” touching of women comes exclusively from his left hand and invariably surprises his left brain which controls the motor functions of his right side. The left, linguistic, side is more conscious and engages in self-promotion; the right side is less conscious and more honest. The implication is that we have evolved a brain architecture that allows self-deception to do whatever is right by us. Sometimes the truth is worth concealing, especially from ourselves.

Social psychology concurs. Across cultures, it is claimed, moral hypocrisy is the rule: people tend to judge others more harshly than themselves for the same infraction. But put people under a form of cognitive load—say, have them memorize a string of numbers while making a moral judgment—and the usual bias toward self disappears. “This suggests that built deeply within us,” Trivers writes, “is a mechanism that tries to make universally just evaluations, but that after the fact, ‘higher’ faculties paint the matter in our favor.”

The question is: is there a price? The cost of deception in nature can be palpable. Stick insects, for example, have grown long and narrow to mimic twigs, but they have foregone the benefits of symmetry to do so: one of two organs—a kidney, an ovary, a testis—have, over fifty million years of evolution, become the casualties of ever-diminishing internal space. Whether self-deception exists in nature is a more difficult question. An intriguing suggestion made by Trivers is that certain birds, just like humans, show heightened physiological arousal to their own calls compared both with those of other species and those of members of their own kind. Might they be trained to peck at a button when they recognize their own voice, and might birds that have lost more fights peck less?

And what about us? Can we at least measure the price of our own self-deceit? Trivers offers the interesting suggestion that the strain associated with lying, even unconsciously, takes a toll on the immune system. The reason for this is that immunity is expensive, requiring the burning of energy and consumption of much protein. For the same reason, the immune system has a reservoir that can be drawn upon for other purposes—often, Trivers claims, at the mere “flick of a molecular switch.” A decision has to be made: attack another male for the chance of sex with a female, or invest internally to fight a parasite? Quickly the body apportions its resources, diverting from the immune reservoirs to the fighting mode. No surprise, then, that high testosterone levels are associated with lower immune response, or that disease is associated with lower testosterone levels (the body is shifting investment to the immune system), or that marriage, which lowers testosterone levels in men, is associated with increased lifespan. Monogamy, in other words, can be seen as a disease that improves our health. 

The salient point is that choices involving psychology, of greater or lesser degrees of self-deception, in turn affect our immune systems. Trivers cites studies that show that people who write about their trauma can improve their immune function; indeed, emotional disclosure is associated with consistent immune benefits—this is one of the reasons that going to a shrink might make you feel better. The converse holds as well: HIV-positive patients who deny that they are infected show lower immune function than those who admit it, and tend to suffer from more rapid progression of their disease. Truth seems to be healthy for us. On those grounds alone, Trivers writes, “don’t ask, don’t tell” should be considered an immunological disaster.

But can we do anything to correct our follies? Trivers believes that it is possible. Becoming aware of the fact that he is mentally cussing out a colleague, for example, has proved useful to him in avoiding breaking glasses while washing the dishes, or running over students on campus with his car. Don’t do the two things at once, he advises! He has advice also about problems of greater scope and significance. Social workers and teachers should be aware, for instance, that abuse by a close relative will take on average much longer to divulge than abuse by a stranger or a further related person, the “selfish gene” logic having presumably selected the switching on of dissociation or selective recall mechanisms to “keep up a good front.” Korean Air has had a spotless safety record since consultants implemented programs boosting copilot independence and assertion, whereas between 1988 and 1998 its fatal accident rate was seventeen times higher than the average American carrier: the long spate of flight disasters, Trivers argues, was the result of the deference to authority deeply ingrained in Korean culture having precluded young co-pilots from challenging self-deceivingly cocky captains. Wars, in Trivers’s account, are primarily due to the overconfidence of corrupt, risk-taking leaders, drunk with the illusion of control and personally immune to their own escapades. The more we recognize this, the less we will fight.


BUT THERE IS a problem. If expressing the truth is good for health, doesn’t that counter the argument that self-deception is adaptive? To be honest, it does, at least to some degree worth expounding. And what about the fact that we often deceive ourselves in negative ways rather than in self-enhancing ones, thinking of ourselves as fatter or skinnier or more stupid than we really are? Trivers does not consider these points, or the possibility that a major reason for self-deception in many cases may be that the costs of truth are simply too high: you tell yourself that you love your wife because breaking up with her is just too painful. That the psychological and immune systems are deeply intertwined is a fascinating suggestion, but it is still very speculative. Even more conjectural is the suggestion that, for genetic reasons, religions are more likely to splinter into rival factions in parasite-rich areas of the globe. Or that, following the logic of genetic investment, women should be better at spotting deception than men, or that the smarter one is, the more deceptive. 

For all of these notions, however suggestive, little if any evidence exists. More importantly, many different causes, some evolutionarily irrelevant, are likely playing a role. Culture is certainly not reducible to genetics. Trying to attribute phenomena as disparate as stick insects, plane crashes, the birth of religions, and the waging of wars to the same genetic and evolutionary logic is rather like explaining why a wooden square peg doesn’t fit into a triangular hole by recourse to the atomic lattice structure of the wood rather than the peg’s geometry. The resolution just seems off.

To his credit, Trivers is aware of this. “I have noticed that the standards regarding my own arguments I am willing to push forward have dropped,” he admits candidly, even while bearing the flag of a rather unapologetic sociobiology. But this has been his strength throughout his career: to offer, in broad logical strokes, theories that others might test and when successful, formalize. “If you put a gun to my head I could not do a T test,” Trivers recently told an audience at Microsoft, with no false modesty. His brutal self-honesty—about his failures with women, his drug habit, his battle over the years with a debilitating bipolar condition—adds to his believability. Trivers has experienced internal conflict, and many of his insights may stem from this. It may take one to know one.

Still, the science, more or less speculative, more or less brilliant, takes up only half of The Folly of Fools. The rest is reserved for various degrees of invective and ranting. Psychoanalysis, social psychology, cultural anthropology, and economics all come in for a drubbing (“the more social the discipline, the more retarded”); and while some of this makes for amusing and even stimulating reading, other parts seem misplaced, unfair, or misinformed. Trivers tells us that economists “tend to be blind to the possibility that unrestrained pursuit of personal utility can have disastrous effects on group benefit,” even though this tension is at the very core of central fields in economics such as behavioral game theory, social choice, and political economy. Social psychology as a discipline is dismissed outright, even though many of the studies quoted in the book (some of them, incidentally, incredibly weak) come from that discipline. Physicists, too, are treated with scorn: “Their social utility, in my opinion, is primarily connected to warfare. Their major function has been to build bigger bombs.” These are the words of a crank. Still, I laughed out loud at the irresponsibly glib takedown of cultural anthropology and science studies—that “the penis, in some meaningful sense, may be the square root of -1.”

Trivers is even less amusing when he turns to politics. False historical narratives, he argues, are just self-deception bumped up to the group level; and fables of origin, religion, and manifest destiny are merely the tools nations and peoples use to justify conquest and violence. This is shallow stuff. It is striking how adamant Trivers is that certain narratives are completely true while others are completely false: shouldn’t they all be equally self-serving, according to the logic of his evolutionary argument? Most uncomfortable to honest readers will be his strikingly naïve and unimpressive treatment of the Israeli-Palestinian conflict, full of half-truths, banalities, and factual errors. A man who has detected conflict even in the ideal of motherly love should know that nothing can be so categorically black and white. But Trivers, when asked recently whether his Middle East politics might turn off people otherwise interested in his scientific ideas, answered—perhaps, one imagines, on a deck in his adopted Jamaica, smoking a joint—”Well, fuck ‘em.”


JUSTICE AND TRUTH are rarely the same thing, which makes it impossible to take some of Trivers’s arguments seriously. Still, something in me respects the unequivocal moral stance while rejecting the lousy history. The means are not always tight, but the ends often seem right. Why is this? A study cited by Trivers offers a clue. Two groups were randomly assigned, and members of the first group were asked to write for five minutes about a situation in which they felt powerful while candy was being distributed among them; at the same time members of the other group were asked to write about a situation of powerlessness and were only allowed to request candy but not to be given any. When all the subjects were asked to snap the fingers of their right hand five times and quickly write the letter E on their forehead, those who had been primed to feel powerless were three times more likely to write the E so that others could read it rather than backward, from their own perspective. Further study showed that the power-primed group was significantly less able to discriminate among human facial expressions associated with fear, anger, sadness, and happiness. It would appear that the ability to apprehend the world correctly, as well as the ability to empathize, is compromised by the feeling of power. 

“The ultimate effect of shielding men from the effects of their folly,” Herbert Spencer once observed, “is to fill the world with fools.” Trivers portrays himself as the inveterate champion of the underdog, always on the side of the weak, the disenfranchised, the outsider. “Power corrupts,” he warns, in a book dedicated to his late friend, Black Panther Huey Newton. He is right. It does. But readers of The Folly of Fools, written by one of the important figures in evolutionary biology, should remember that the heart can often deceive the mind. Our truths are never too far from our prejudices. 

Oren Harman is the author of The Price of Altruism: George Price and the Search for the Origins of Kindness (W.W. Norton & Company).  This article appeared in the October 25, 2012 issue of the magazine under the headline “Deceptions.”