ScienceDaily (Aug. 13, 2010) — Trusting others may not make you necessarily a fool or a Pollyanna, according to a study in the current Social Psychological and Personality Science (published by SAGE). Instead it can be a sign that you're smart.
Researchers asked study participants to watch taped job interviews of 2nd year MBA students. Interviewees were all told to do their best to get the job. Half of the interviewees were completely truthful; the other half told at least three significant lies to appear more attractive for the job. All interviewees were guaranteed $20 for making the job interview tape, and both the liars and truth-tellers hoped to receive an additional $20 if a supposed "lie detection expert" watched the tape and believed they were telling the truth.
Several days before the participants watched the tapes, they filled out a questionnaire that measured their trust in other people, with questions such as "Most people are basically honest," and "Most people are basically good-natured and kind." They then watched the videos, and rated the truthfulness and honesty of the interviewees.
People high in trust were more accurate at detecting the liars -- the more people showed trust in others, the more able they were to distinguish a lie from the truth. The more faith in their fellow humans they had, the more they wanted to hire the honest interviewees and to avoid the lying ones. Contrary to the stereotype, people who were low in trust were more willing to hire liars and they were also less likely to be aware that they were liars.
http://www.sciencedaily.com/releases/2010/08/100813090457.htm