Book Review: Why We Lie: The Evolutionary Roots of Deception and the Unconscious Mind

Reviewed by Tamar Frankel, Professor of Law Emerita, Michaels Faculty Research Scholar, Boston University School of Law, USA.

Why We Lie: The Evolutionary Roots of Deception and the Unconscious Mind, by David Livingstone Smith (St. Martin’s Press, 2004) is a fascinating book about a fascinating subject. Two related general themes run throughout the book. The first theme is that lying is deeply embedded in our subconscious as a result of evolution. Most of the book’s stories are linked to this theme. Evolution means simply that those who survive by lying possess among their talents the ability or the features that deceive predators who could harm them, as well as the ability or the features that deceive victims whom they may harm. The living things that did not have the knack to deceive or that had less ability to lie died of starvation or by being eaten. They did not survive to reproduce as much as those who possessed the quality to lie and had a better chance of multiplying. Thus, evolution produced the best liars.

The book opens with the discussion of living things, both predators searching for food, and their victims searching for an escape. Predators and victims have lied by developing mechanisms and features that helped hide the features that are likely to tell the truth about themselves, and feign features that they do not have. For example, predators shun a species of butterflies that has a bitter taste. Another species of butterflies have a sweet taste. However, predators avoid the butterflies of the sweet tasting species, that look like the bitter tasting ones. Those sweet tasting but look-alike bitter tasting butterflies multiply. There develops a species of sweet-tasting butterflies that lie about how they taste by the way they look.

A similar evolution occurs in both predators and their victims. Those who blend into the background survive more readily than those who stand out. The leopard evolves as well as certain types of antelopes. Lying helps them get food or avoid being eaten. In fact, predators may also be the victims of other better-lying predators and victims may also be the predators of less lying and more truthful species. Therefore, each might lie in ways that result in better chances for survival.

The second theme that is inevitably related to the first theme is sometimes stated in the book but mostly demonstrated. In the evolutionary context, living things that lie do not intend to lie, mislead or deceive. In fact, they might not even intend to survive by means of deception. They simply do. Thus, evolution cleanses lying of its pejorative sense. The reason why beings lie does not relate to these beings’ intent or choice. It relates to their innate abilities and the resultant survival by greater procreation. The essential building block in Dr. Smith’s theory is unintentional, blind evolution. The unintentional and inevitable averting of harm (of starvation or being eaten) by misleading predators and prey.

A number of issues arise from this thesis.

First, the term “lying,” which is used in the book, is somewhat incongruous. We use the word “lying” to denote an intentional action designed to mislead others. That is why lying carries a pejorative sense. It is synonymous with deceit, double-faced being, dishonest and insincere action, and alike. The word carries with it a social judgment of an anti-social behavior. The word implies not merely impact on others, but a degree of intent. Unintentional behavior does not carry with it that degree of disapproval.

Thus, the dual themes of the book pose a paradox. The book combines the word lying (bad behavior) with inevitability. Implicitly, the combination removes the aura of bad behavior from lying. When the author inquires into the nature of deception his thesis is that lying is a result of evolution and subconscious behavior rather than intentional behavior. He focuses on the function of lying. He notes, for example, that what we call lying depends on its purpose. Lying in war – avoiding being eaten — is not (bad) lying. Lying to helpless parties – eating others — is (bad) lying. But if humans lie without intent and when the lying is inevitable, they cannot be personally responsible. The badness and goodness of lying is then relegated to the high sphere of philosophical contemplation but with no implication on actual inevitable non-volitional behavior. One can then say that the inevitable behavior was bad or good in the abstract, but the behavior is unchangeable.

The second issue raised in the book is that misleading others assures the success of the species. It results in the liars’ survival and proliferation. The conclusion of this theory is that by lying both predators and their victims can multiply. Evolution sharpens and refines their ability to lie about themselves. And yet, at the same time, if both predators and victims increasingly multiply, an equilibrium is maintained, which allows both to survive. While the balance between predators and victims can remain the same, the liars in each group are the winners by evolution.

This conclusion may not be always correct. Most beings do not live alone. Their survival depends on the support of others. Sometimes their survival depends not only on the support of their own species but the support of other species. If and when lying harms society, whether of living things or humans, then society, composed of the non-liars might rise up against the liars and reciprocate by terminating them. Thus, at most, evolution may support species of liars against other species of non-liars, but not liars within the species or their colonies.

The book does not tell us much about the equilibrium between predator deceivers and fleeing prey deceivers. Neither does it tell us much about the rules that the society of humans imposes to maintain an equilibrium and even overcome the genetic subconscious tendency to lie, when it is strong. I would have liked to know more about the author’s explanation of social pressures not to lie and the evolution of societies and people who changed their ways and succeeded, and therefore produced more off-spring like themselves. The book focuses mainly on the act of lying itself and the theory of its source. It does not focus as much on the consequences of lying. For example, if the other party is aware of the lie and believes that the lie was intentional, the effect may be to undermine the trust among the parties, and that may have repercussion to both parties. In contrast, some lying is socially desirable and approved of, as for example, untrue compliments.[2]

Third, if evolution is the foundation of lying, then it cannot be entirely relational. It includes the reaction of living beings to a hostile environment. According to an overall evolutionary definition, lying will occur even though it could not deceive anyone. If animals develop fur in a cold climate, evolution helped protect them from freezing. How can the growth of furs be lying? The fur is grown in the open; it does not deceive. Further, this adjustment is not reactive and relational. The animals’ behavior will not convert freezing weather into a warmer one. To be sure, by blending into their snowy white environment the animals may hide their presence, and use this trait to either hide from predators or find their victims. Dr. Smith’s definition would include such adjustment to the environment within his definition of lying. And yet, his stories and examples suggest that his definition means deceiving others causing them to change their behavior. Lying which does not deceive or seek to deceive stretches the meaning of the word far beyond acceptable boundaries.

In my understanding lying is relational.[3] It should be aimed at someone or something that could react to the lie. A successful lie depends on the other party to whom the lie is addressed. If that party is aware of the truth, it is not deceived and the lie is still a lie, but is not effective. But one cannot lie to a stone.

Fourth, Notwithstanding the evolutionary basis, the book’s basic tenet is that lying is a relational phenomenon, involving at least two parties. The author bifurcates human beings. Humans are not one but two. They contain two separate entities: the conscious and the unconscious. If humans are two, they can deceive themselves. The author argues that self-deception is prevalent in humans and is driven by the force of evolution. People not only lie to themselves. Like other living things they lie automatically, without intention, cognition or awareness.

When applied to humans, however, the evolutionary theory is more complicated and attenuated. We do not know whether plants and other living things intend to lie. However, there are studies that demonstrate intentional lying by humans and primates. For example gorillas and chimpanzees have been observed to deceive their own kind in order to gain food or attract mates. Therefore, even if lying is evolutionary, it does not mean that it is always unintentional, automatic, inevitable, and uncontrollable. Once intention is recognized as part of lying, lying is only partly evolutionary. One can lie to one-self but one can also control one-self and one’s self-deceit.

While “Why We Lie” starts with evolution, it is mostly devoted to the interesting manipulative tendencies of humans. Therefore, intention must be added to the evolutionary effect. Arguably, misleading actions are not solely the product of evolution but also the product of choice. Not so, says Dr Smith. Like in non-humans, lying by humans is rooted in the subconscious. Perhaps evolution is still at work, leaving fewer humans who do not lie effectively, and keeping alive and prosperous more humans that can lie effectively. While Dr. Smith distinguishes between the lies of living things that result from natural evolution, and manipulative lies by higher-level mammals and humans, he links the two together by their common source — evolution.

“Why We Lie” is rich with stories, anecdotes, and psychological as well as sociological analyses. It shows the rich variety of methods and signals in which humans communicate, with their multi-layered meanings. All seem to be the products of evolution. The success of the manipulative liar lies in the weaker ability of others to discover and uncover the lies, just as the success of the tiger lies in its ability to run faster and be stronger than the fleeing doe. Human “decoding” lies requires focus and extensive experience. It requires piecing the veil of the words, which many people do not practice. Therefore more people are “playing poker in the dark.” They are lied to and do not even know it. They lie and do not know it. Presumably, the prototype of the weaker liars is more likely to disappear because their ability to succeed in life is more limited.

Dr. Smith views lying as the tool by which people attempt to affect and even create and control, their reality. That includes not only their relationship with others, but also the relationship with themselves: their self-perception. Thus, to the self-selection of those with tendencies to get food and avoid becoming the food of others is added the tendency to intentionally or instinctively better their relationships with their environment and with themselves. Self-deception, however, does not always bring success. It may result in failure against those who see more clearly and dispassionately. Furthermore, not only intention is subsumed in the process of evolution but also logic and reason. If this theory is true, then the human race is genetically evolving into a race that is increasingly deceptive, both to gain from each other, and to avoid loss from each other. Whether the equilibrium among expert and less expert liars is maintained or changed, the ability to lie must rise genetically with each generation as the liars win over the non-liars, live longer, and end with more off-springs to carry further and refine their lying abilities.

“There is evidence of innate human tendencies to manipulate others. Con artists manipulate investors into investing in their worthless notes. The cons use true and false statements; honest and fake signals. These are used to maneuver investors into doing what they might otherwise not do, and divert them from using their judgment.

Who does not manipulate others once in a while? We smile indulgently when a child manipulates her parents into buying a toy. Pretending is a gift that humans possess at a very early age. A child may put a banana to her ear as a telephone, even before she understands fully the falsity of the situation or distinguishes among mistakes and between pretense and false beliefs. Not only humans, but also primates manipulate by deception. Chimps and other animals are “artful liars.”[4]. A gorilla hid fruit that she found and walked nonchalantly away only to return three hours later to retrieve the fruit when no other gorilla was around. A chimp whose mother rejected his attempt to suckle pestered a male until the male leaned in exasperation; the infant shrieked and the mother ran over and offered him her nipple. The sign language-user chimpanzee, Lucy, offered another chimp a plastic flower, which he understood as a gesture of friendship, only to bite him when he reached for the flower. A pair of baboons acted precisely like conniving con artists in cooperating to deceive a third.[5]

Manipulation and guile, for good and evil, go back thousands of years, as the stories of the Old Testament tell us. Both Abraham and Isaac presented their beautiful wives as their sisters for fear that the local residents would covet them.[6] Rebecca tricked her blind husband, Isaac, into blessing her favorite younger son, Jacob.[7] King David fell in love with Bathsheba, the mother of the great King Salomon, as she took her bath on the roof, where he could see her. When he wanted to marry her, he sent her husband Uria to be killed in war.[8] These acts were driven by men’s fear, by a mother’s love, a man’s lust and a woman’s ambition.

Modern man, like pre-historic man, seems to have innate tendencies to manipulate. It has been suggested that “genes for lying play a crucial role in propagating this species.” Ability to lie is rooted in our DNA “Some people excel at falsehood.” These natural liars are usually quite aware of their talent, since they have deluded parents and teachers to escape punishment since early youth. They are confident and feel no fear or guilt about getting caught. Yet they are not sociopaths; they don’t use their skills to hurt other people. In fact, they score the same as other people on psychological profiles. But they seem to do better in certain careers, like sales, diplomacy, politics, acting, and negotiating.'[9]

Further, manipulation is not necessarily effected by direct lies. “’Human communication is not just a transfer of information like two fax machines connected by a wire; it is a series of alternating displays of behavior by sensitive, scheming, second-guessing social animals.’ Genuine communication where symbols, words or vocalizations have a meaning only occurs when the speaker intends listeners to understand the meaning of the word as the speaker understands it.”[10] But even then, mistaken receptions may occur, especially when the speaker does not want the listeners to misunderstand the true meaning of the words as he understands them.

What emerges from the reading of “Why We Lie” is a sense that as species become more advanced they automatically and inevitably become better and more sophisticated liars and the discoverers of lying. The discoverers lag behind and the survivors spiral to higher levels of lying. Neither society nor individuals can stop this evolutionary process. For me, this is not a comfortable and convincing conclusion. From both social and personal point of view, lying is inefficient. It requires others to invest time and attention in ferreting out the truth. It requires the liars to remember their lies and to invent new ones. Lies breed suspicion, insecurity, and reciprocity. Most of all, I doubt whether lying is inevitable. I am not sure whether evolution is so dominant as to overcome cognitive action.

“Why We Lie” ends in the difficult and intriguing question of how much proof should support the theory which the book proposes. The book suggests numerous explanations and hypothesis concerning lying. Dr. Smith anticipates the criticism that the book’s assertions are not proven scientifically and that his suggestions are not “scientific” in the sense of pure science as opposed to the humanities.

Dr. Smith passionately rejects these objections and criticisms. He asserts that there is value, and scientific value at that, in offering hypotheses, even without “solid proof,” and even if they are shown to be wrong later. The suggestions and ideas raise interest, he argues. They entice more research, whether to prove or disprove the proposed hypotheses that he makes. In raising the ideas, he finds his mission and the justification for writing the book and viewing it as scientific.

I find this controversial part of the book most intriguing for a number of reasons. First, it demonstrates the different views of different disciplines with respect to “truth” and “reality” and the method by which they are proved. For example, economists have for many years viewed themselves as sociologists, and even though they used numbers, the numbers were not the decisive proof of their theories until about 1950. It was then that the requirement for quantifiable proof emerged, and was further developed with the aid of computers. Some economists, however, denied the hegemony of quantities and numbers, including Noble Prize winner George Stigler.[11]

Further, attempts to show causation in the social context will usually fail, whether or not supported by numbers. Effects of events and the interaction of units within chaotic systems such as societies cannot be meaningfully and accurately explained. Further, even a single human is also highly complex. A human affects and is affected by others, by the environment, by the food he eats and the cloths he wears. Humans make horrendous mistakes. Some humans learn from mistakes; some justify and repeat them. Humans use intuition and experience. The pride of a researcher in showing a counter-intuitive finding may be short-lived. Intuition based on experience and perhaps on the marks of the evolutionary process may end the winner, as Dr. Smith suggests. In these circumstances causation is near impossible to prove.

If Dr. Smith attempts to convince the scientists that he is a scientist too, I would assure him that there is no need to convince. With due respect to those who demand more precise proof I side with him. There is great value in hypotheses that might make sense, or even partial sense, give food for thought, and lead to further experiments. For example, I believe that those who are convinced about something are also more convincing to others. I have no proof of this assertion, and could spend time setting up an experiment to prove it. I also recognize that this statement is not entirely accurate. Some people may be turned-off by a person who is too convinced. Some people have their own strong convictions and are not swayed by those of others. And some people recognize that the measures of convincing and being convinced may differ, depending on the context. Conviction maybe strong, medium or weak. The answer depends on all these variables and more.

So what would I do? I would make the statement and distribute it as widely as I can. I choose to leave the idea to others and invite others, who are more expert than I, to experiment. They may decide whether this line of inquiry is interesting or important. Whether my work on this point is cited by others may be one indication of a following. Another indication may be whether I am asked to speak about a subject that involves this statement. In other words, I may get some “feel” of the consensus of others and nothing more. Even without followers, all others may be wrong and the truth might not be followed. This does not mean that my statement is less truthful, at least some of the time. What did Dr. Smith do? He wrote a book. That may be the most scientific way. Raise the idea and see what happens.

I enjoyed reading Dr. Smith’s book. I hope he writes a more generalized theoretical piece that articulates his disagreement with colleagues on this issue – the issue of proving one’s suppositions and ideas.


  1. David Livingston Smith, Why We Lie, The Evolutionary Roots of Deception and the Unconscious Mind, St. Martin’s Press. New York (2004). The book seems to be related to a previous book by the author on this subject, bearing a somewhat different name.
  2. Trust and Honesty, America’s Business Culture At a Crossroad, Ch. Four (2005) (Oxford University Press,
  3. Id.
  4. Iain Pears, An Instance of the Fingerpost 244 (1998).
  5. Id. at 171, 172 .
  6. Genesis XX (“And Abraham said of Sarah his wife, She is my sister: and Avimelech king of Grar sent, and took Sarah”). The charade did not help, as the King took her anyway, only to her return later, when God punished him.
  7. Genesis XXVII.
  8. Samuel Chapter, XI, XII (the child Barsheba conceived while married died. After she married David, she bore Salomon, who became one of the greatest kings).
  9. Pears, An Instance of the Fingerpost at 245 (1998).
  10. Id., at 116. The material in quotes is an unpublished excerpt from a manuscript by Tamar Frankel, Con Artists and Their Victims (on file with the author).
  11. George J. Stigler, “Economics-The Imperial Science?” Scandinavian Journal of Economics 86 (No. 3, 1984): 311 (coining this branch of economics: “Imperial Economics”).

Citation: Frankel, T. (2005). Review of Why we Lie: The evolutionary roots of deception and the unconscious mind by David Livingstone Smith. Human Nature Review. 5: 45-52.

Tamar Frankel
Professor of Law Emerita
Boston University School of Law

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