The Folly of Fools: The Logic of Deceit and Self‐Deception in Human Life  . Edited by RobertTrivers . New York : Basic Books , 2011 . 397 pages. $28.00 .

Readers of Zygon: Journal of Religion and Science should be familiar with important contributions to theories of social evolution, conflict, and cooperation developed over the course of many years by Robert Trivers, professor of anthropology and biological sciences at Rutgers University. Since the early 1970s, he has proposed such influential theories as reciprocal altruism and parental investment, and he is often quoted as one of the main theoretical influences for authors like Richard Dawkins and many others. In his book The Folly of Fools, Trivers explores, in a popular key, another theory he is known for: the role of self‐deception in biological evolution in general and social evolution in particular.

This highly readable book is full of clever examples of evolutionary processes relevant for human social evolution described by a major theorist, and for that reason it is worthy of serious consideration. Where this book falls short of its lofty goals is in its account of religion.

At first this book is hard to characterize because it reads like a general text in popular evolutionary biology without much care for providing a full account of sources in endnotes, but at times it sounds like a polemic with the social sciences for not taking biology seriously. Only at the end does Trivers fully reveal how personally important this topic is to him and how much this book relies on practical solutions to everyday problems in his life. In short, in order to maximize our inclusive fitness, we need to minimize self‐deception, and the only way we can achieve this is to use evolutionary biology as our guide for all problems of everyday life. Trivers will help us transcend our routine self‐deception by helping us understand those underlying evolutionary processes that shaped it.

By relating self‐deception to deception, which he finds ubiquitous in nature, Trivers explains the evolutionary roots of self‐deception. It would be very hard to understand self‐deception or deception if we would only look at people, so Trivers gives numerous helpful examples from other animals. In the evolutionary struggle between deceiver and deceived, ever‐greater complexity arises on both sides. For example, among butterflies, being able to present themselves as poisonous is very often equivalent to being poisonous. For potential predators, being able to differentiate between genuinely poisonous individuals and those mimicking poisonous individuals is evolutionarily advantageous. The struggle between mimics and predators creates a ratcheting effect that produces even better mimics and ever more capable predators. Trivers claims that in birds and mammals this process eventually also favors intelligence.

Trivers insists that self‐deception evolved in order to help deception. In any social context among human beings, who evolved to be very good in detecting deception in social situations, one helpful strategy is to deceive others without knowing that one is deceiving them. In this sense self‐deception is much more efficient than keeping track of all kinds of deceptions that would be needed to produce similar results. There is a trade‐off between cognitive loads and self‐deception.

Trivers is at his best when he uses examples from various studies in animal behavior and presents them through his lens of evolution of sociality based on a gene point of view. However, this book becomes really different when he discusses anecdotal examples of human behaviors ranging from aviation disasters to his personal love life. Trivers’s book becomes really disappointing when he discusses one of his prime examples of self‐deception: religion. For one, his main sources for self‐deception in religion seem to be Richard Dawkins and Daniel Dennett, with some help from a very informative book by Robert Wright, The Evolution of God. Besides those authors, Trivers uses Richard Sosis and a few others. When it comes to the scientific study of religion, we have seen in the past 20 years a steady rise in theories of religious behaviors based on both cognitive and various evolutionary approaches, and there is an abundance of literature in this area that Trivers did not seem to bother checking. Trivers is not clear on what behaviors does he have in mind when he talks about religion. Here is one of his platitudes: “Religions range from animists to monotheists to nontheists to atheists and then from Christian to Hindu to Buddhist to Muslim to Jew, with many subspecies” (Trivers 2011, 277). Trivers presents us with a view that religion is a mixture of self‐deception and behaviors that benefit from within‐religion cooperation at the cost of lowered cooperation with outsiders. Trivers makes some interesting connections between religion and health, but without clearly citing any sources for studies of such correlations, it is hard to assess the value of his theoretical contribution. Trivers relates his concept of religious diversity, or a number of religions per unit area, to the number of people who die from parasites in those areas. He claims that religious diversity and high parasite counts are related. This leads him to conclude that religious groups split in order to avoid parasite loads, assuming that religious groups promote in‐group cooperation and out‐group isolation. Regardless of how interesting Trivers's hypothesis is, it does not make clear what he calls monotheism and what he calls polytheism. Are these concepts something descriptive within his theory, or are they self‐reported by religious practitioners? His point remains completely obscure. With all his respectable effort to avoid self‐deception Trivers seems to fall for deceptively simple accounts of religious behaviors. In many ways religion is for Trivers a case in point when it comes to self‐deception. He lists “some of the key features” of what he calls “Western religions (and some Eastern ones)” (Trivers 2011, 282–5). First, religion gives a unified privileged view of the universe for your own group; second, religion presents a series of interconnected phantasmagorical things (gods, afterlife, etc.); third, prophets or founders of religions get deified; fourth, books are treated as received wisdom from God; fifth, faith supersedes reason; and finally his last category is that religious believers think that they are right. These are the main mechanisms through which religion perpetuates self‐deception. When warning about dangers of religion, Trivers explains how religion leads to self‐righteousness and that in turn leads to warfare. Another interesting point that makes no sense whatsoever when reading Trivers’s account of religion is that he refers to God as “she,” and it is not clear how this is related to self‐reports by religious practitioners or to any established use in relevant literature.

Where Trivers really holds nothing back is in his account of the social sciences that do not take evolutionary biology seriously. He accuses those social scientists who do not rely sufficiently on the ability of evolutionary biology to defeat self‐deception to be responsible for distortions of reality intended only to keep them in positions of power. The success of natural sciences is based on anti‐self‐deception devices like, for example, giving in advance clear definitions of all relevant concepts. Trivers maintains that in social sciences whole subdisciplines exist only because of poorly defined words. One only wishes that Trivers would apply this suggestion to his own definition of the word “religion.” Trivers finds most self‐deception in cultural anthropology and social psychology. His most disparaging comments are reserved for psychoanalysis and economics. For Trivers psychoanalysis is self‐deception in the study of self‐deception, and economics, which he dismisses with impunity, is not a science as long as it does not fully ground itself in evolutionary biology. Trivers is at his best arguing against researchers who used the ultimatum experiment in which a person is supposed to accept an unfair split of money by anonymous others in order to show that we evolved to fit this unusual lab situation. Trivers claims that this is the same as saying we evolved to be afraid when watching a horror film in order to fit movie showings (Trivers 2012, 312).

In his last chapter Trivers talks more candidly about his existential context that in retrospect becomes visible throughout his whole book. He gives examples of his thoughts about inflicting harm to colleagues who disagreed with him, his competitive attitude toward perceived rivals in romantic interests, and so on. We read about his search for a method to rise above self‐deception in everyday life, and we are presented with arguments that natural sciences in general and evolutionary biology in particular give us the ability to look at ourselves without the negative effects of self‐deception. We get a sense of a serious working scientist coping with compulsions that cannot be ignored and that cannot be subsumed under fantasies that would only aggravate them. In spite of its obvious shortcomings, when it comes to a serious approach to the scientific study of religion, this book presents a lasting contribution to a difficult part of evolutionary theory of social behavior, and it gives us a valuable glimpse of the inner self of one of the major theorists of evolution in our times.