Why might there be a link between intelligence and trust in others? "One explanation is that intelligent individuals are better at evaluating others' trustworthiness, meaning that they tend to select into relationships with people who are unlikely to betray their trust," the authors wrote. Stated another way, smarter people might be more selective about who they trust. Secondly, more intelligent people "may be better at identifying when any particular person would be likely to act untrustworthily, based on the characteristics of the prospective interaction." For example, if you give thousands to somebody you just met on Craigslist, there is a chance they might just disappear with your money. Even if they seemed reliable.