Human beings lie incessantly, both to others and to themselves. In this paper, we will focus on interpersonal lying—lying to others. Why does it occur? And why does it occur so often? We will answer both questions; we will find that lying among human beings has multiple determinants. But these determinants fall into two categories: psychological (these being the immediate psychological inducements to lying) and evolutionary (these being the evolutionary basis of these inducements).
Let us first discuss the psychological determinants of lying. There is one obvious such determinant: Lying is often convenient, and telling the truth is often inconvenient. If I tell my boss the truth and tell him that he is an incompetent buffoon, I will not get promoted and will likely lose my job. If I lie and tell him that he is a competent, I will keep my job and perhaps get a promotion.
But the real question is: Why do people lie so much? People seem to lie far more than can be explained in terms of their practical self-interest. Why is that?
According to Psychology Today, there are six reasons why people lie when there is no obvious reason for them to:
First, they believe that it is important to lie in the context in question. Here is an example. My friend Ted sometimes smokes. The other day I asked him if he had had a cigarette that day. (He smelled of cigarette smoke.) He hesitated and then said ‘no’, squirming and looking ill at ease. (Later in the conversation, he absent-mindedly mentioned that he had had a cigarette earlier in the day.)
Why did Ted lie? He seemed to think that his having had a cigarette revealed some deep character-flaw—that it showed a lack of self-control. And indeed it did—but all human beings lack a measure of self-control. But for Ted, precisely because he was trying so hard to quit, he was particularly ashamed of this lapse, and seemed to think that I would be comparably disappointed in him.
Second, people equate telling the truth with giving up control. A friend of mine once made a rambly point about the Pythagorean theorem. I crisply articulated it for him, and then asked: Is that what you meant? He defensively said ‘no’, and then declined to say what he did mean. Why did he do this? Because he didn’t want to be bested; he felt that, if he conceded that I had understood what he was saying better than he did, he would be giving me some kind of power or authority over him. (Which he probably would have been. But which would have been smaller than the respect from me, and from himself, that he was giving up by being so petty.) He wanted his point, inane as it was, to be his property, to be understood by him and him alone. Many obscure writers, e.g. Wittgenstein, always claim that they are being misunderstood. It gives them a way of seeming mysterious and feeling superior.
Third, they don’t want to disappoint the people they are lying to. This is one reason why college students lie to their parents about their grades or about cheating on assignments. They don’t want their parents to be disappointed in them. It is also quite likely why my friend Ted lied to me about smoking a cigarette. He looked up to me and seemed to think that I would be disappointed in him if he told the truth.
Fourth, “lies snowball.” Smith lies about smoking (‘I didn’t smoke today’). Then he has to lie about why he smell likes smoke (‘I was with my professor, who was smoking’). Then he has to lie to support the second lie (‘I was seeing him to discuss my paper’). And so on.
Fifth, they believe (or half-believe) the lie. “Have you been sticking with your diet?”, I ask Sally. “Yes I have, Yuri.” She is not telling the truth. She has obviously been ‘pigging out.’ But her memory is selective, and she has distorted the memories that still has access to. She isn’t exactly lying; nor is she exactly not lying. What we have here is a mixture of self-deception and deception of someone else.
Six, they want to believe the lie. A former friend of mine, Brad, would lie about his grades and his test-scores. He got a 710 on this verbal SAT but said that he got a 770. (I knew this because he initially told the truth, and then ‘edited’ the truth over time.) Brad wanted to be, and to be seen as hyper-smart, when in actuality he was only moderately smart. And to this end he lied, both to himself and others.
These are the psychological reasons why people lie excessively. But the evolutionary reasons are less obvious. There are two quite different such reasons.
First, in the animal kingdom, survival is often about stealth. Even powerful animals, such as leopards and tigers rely greatly on stealth to catch prey and thus to survive. As for animals that have little power, such as most rodents, their survival is almost entirely dependent on their degree of stealth.
Human beings are no exception to this. Hunting is about being stealthy and also about laying traps. And these, though not exactly forms of lying, are forms of misleading and therefore of being deceptive.
Second, once human beings mastered the art of surviving in the wild, they had to master the art of surviving within society. So for human beings, evolution is a two-phase process: there is pre-social evolution and social evolution. And what it behooves people to do in the wild in order to survive, it doubly behooves them to do in society. Succeeding in society, and sometimes even just surviving, involve conforming to other people’s desires and expectations and therefore systematically falsifying one’s beliefs. It seems likely that people who cannot do this will tend to be weeded out---as in, they will tend not to procreate or to procreate insufficiently---simply because mates do not want to be with a ‘loser’, this being what a chronic truth-teller inevitably becomes.
Given that deceptiveness is thus doubly-selected for---being selected by pre-social as well as social evolution—we have seem to have a seventh reason, to add the to the previously mentioned six, why people lie: deceivers are naturally and sexually selected for. So people lie because liars are more likely than non-lairs to make the evolutionary cut.