The researchers discovered the correlation between intelligence and a willingness to trust others by analyzing data from the General Social Survey, a public opinion survey collected every one or two years in the United States.
"Intelligence is shown to be linked with trusting others, even after taking into account factors like marital status, education and income," said lead author Noah Carl. "This finding supports what other researchers have argued, namely that being a good judge of character is a distinct part of human intelligence which evolved through natural selection."
The Oxford sociologists say they can't yet offer a definitive explanation for why such a correlation exist, but surmise that smarter people are more confident making judgements of character, or may be better at understanding the context of a social interaction where trust is mutually ensured.
"People who trust others seem to report better health and greater happiness," explained Oxford sociology researcher Francesco Billari. "The study of social trust therefore has wider implications in public health, governmental policy and private charity, and there are good reasons to think that governments, religious groups and other civic organizations should try to cultivate more trust in society."
The researchers pointed out that important social institutions like welfare programs and the stock market rely on trust. So it's important to learn which factors enable trust.
The findings corroborate previous studies that showed a trust-intelligence connection among European populations.
The study was published in the latest edition the journal PLOS ONE.