In 1913, Eleanor H. Porter published a young adult's book, Pollyanna, about a girl who finds the good in everything. Soon, Pollyanna became synonymous with naively optimistic people—people who are often too trusting and easily duped. This stereotype appears to be misleading; trusting people are better able to detect duplicity than untrusting folks.

Nancy Carter and Mark Weber from the Rotman School of Management at the University of Toronto videotaped second-year MBA students interviewing for a fake job. The researchers instructed half of the interviewees to be absolutely honest and the other half to lie. All of the participants received $20 for their efforts and Carter and Weber promised the interviewees an additional $20 if a lie detection expert believed they were telling the truth.

The researchers then asked a different group of participants to answer a survey, assessing the amount of trust they place in others. The participants watched the tapes and evaluated how honest they believed each interviewee was. Those people who were more trusting were better able to discern whom the liars were whereas less trusting people had a difficult time differentiating between liars and truth tellers.

"Although people seem to believe that low trusters are better lie detectors and less gullible than high trusters, these results suggest that the reverse is true," the coauthors write in the paper, which appears in Social Psychological and Personality Science. "High trusters were better lie detectors than were low trusters; they also formed more appropriate impressions and hiring intentions."