09/12/2011 12:33 am ET Updated Nov 12, 2011

Liar, Liar .. What Personality Types Lie The Most?

Who lies? My best guess is that everyone does. That's what my research, and other work, too, suggests. For example, in one of the sets of studies that my colleagues and I conducted, two groups of people -- 77 college students and 70 people from the community -- kept diaries every day for a week of all of the lies that they told and all of their social interactions lasting at least 10 minutes. The college students lied in one out of about every three of their social interactions, and the people from the community lied in one out of every five interactions. Over the course of the week, only 1 percent of the college students and 9 percent of the people from the community claimed to have told no lies at all. (Yes, my first thought was -- they are lying about not lying.)

Even though my best guess is that everyone lies, it is clear that some people tell lies much more readily than others. In my diary studies, for instance, the lie-telling "champ" told 46 lies over the course of the week, or close to seven lies a day. Who are these people who tell lies much more frequently than the rest of us? I'll set aside the clinically diagnosable in this post, and just consider everyday liars. Do they share certain personality characteristics? Are there sex differences? Does age matter? Is the tendency to tell lots of lies linked to the quality of your relationships?

The Personality of a Liar

In the diary studies, all participants filled out a number of personality measures. We used that information to see if certain kinds of personality types are especially likely to tell lots of lies.

When I posed the question, "who lies?" did a stereotype pop into your mind? Did you guess that frequent liars are more likely to be manipulative and scheming people than are more honest folks? If you did, surprise! I'm not going to tell you to abandon your preconceived notions about liars. People who are more manipulative (as measured by a Machiavellianism scale and a measure of Social Adroitness) lie more often than people who are less manipulative.

Manipulative people tend to care about themselves, so you might also think that liars are generally people who do not care about other people. That's not totally true. Frequent liars can also be people who care too much about other people. What they care about, in particular, is what other people think of them. This personality type describes people who are always worrying about the impression they are making on other people. "Oh, what will she think if I say that?" "Will he think I'm a total loser if I do this?" This is the impression-management personality type, and those people tell lots of lies, too. Interestingly, these kinds of people know that they lie more than other people do. That's noteworthy, because like the citizens of Lake Wobegon, the participants in our diary studies believed that on the average, they were above average in honesty.

Guess who else lies more? Extraverts. Here's where it mattered that we kept track of people's social interactions and not just their lies. If we only counted lies, then extraverts would have many more opportunities to tell lies than introverts, because they spend more time around other people. Instead, we looked at rates of lying -- the number of lies people told relative to the number of opportunities they had to tell lies. Extraverts lied at a higher rate than introverts (though the difference was not big).

Why do extraverts tell more lies than introverts? I think it is because the little lies of everyday life can make social interactions run smoothly. Extraverts are versed in social niceties, and practice them so often that they probably do not even realize how often they are lying. In fact, we found some evidence for that among the college students. At the end of the week, when the extraverts saw the total number of lies they had told, they said that they were surprised at how often they had lied. We don't really know for sure, though, why extraverts lie more, so feel free to share your insights.

The results for one other personality trait are totally obvious. That trait is responsibility, as measured by a scale by the same name that picks out people who are responsible, honest, ethical, dependabl, and reliable. Responsible people were less likely to tell lies than less responsible people -- especially the kinds of lies that are self-serving.

Click here to learn about sex differences in lying, the connection between lying and the quality of your relationships, and whether age matters in the tendency to tell lies. If you are interested in more of the details of the diary studies, including the issue of whether the participants may have been lying to us about their lies, you can find the original journal articles in "The Lies We Tell and the Clues We Miss". A more reader-friendly version is available in "The Hows and Whys of Lies". Also relevant to deception is this post on the screening of airport passengers by observational techniques.