The Psychology of Lying: Why Everyone Lies and Nobody Admits It

Bella DePaulo and her colleagues asked college students and community members to keep a diary of all their social interactions and to record any lies they told. The results: on average, college students lied in about one in three of their social interactions. Community members lied in about one in five. These were not elaborate deceptions — most were everyday, unremarkable lies.

We lie constantly, and we have a poor memory for our own lies and a selective attention that prefers not to notice them. When people are asked to estimate how many times they lied in the previous week, they consistently underreport. Part of this is motivated forgetting. Part of it is that we do not classify many of our lies as lies at all.

DePaulo's research identified several categories. Self-serving lies protect or promote the self. Other-oriented lies protect someone else's feelings — the fine, thank you response to how are you, the forced compliment about a friend's haircut, the polite appreciation for a terrible gift. The distinction matters because other-oriented lies are so prevalent and so socially rewarded that the category of lying itself becomes blurry.

Society genuinely runs on a layer of social lubricant that most people would classify as polite rather than deceptive. Radical honesty — saying exactly what you think all the time — is not well tolerated socially and is arguably not something most honest people actually want from those around them. The social function of many everyday lies is real.

Where deception becomes more serious is in self-deception — in the lies we tell ourselves about our motives, our honesty, our consistency. People who score high on tests of lying to others also tend to score high on self-deception. There may be a general capacity for maintaining false narratives that applies both outward and inward.

Research on detecting lies has consistently found that humans are poor at it — barely better than chance, and no better with confidence. Training in lie detection improves accuracy modestly at best. The confident intuition that you can spot a liar is itself, usually, a lie you are telling yourself.