Are conservatives more likely to stick to a diet than liberals? The answer might be yes.
In a paper published Monday in Proceedings of the National Academy of Sciences, researchers say there is a link between political ideology and the ability to exert self-control.
In a series of three studies with more than 300 participants, the authors found that people who identify as conservative perform better on tests of self-control than those who identify as liberal regardless of race, socioeconomic status and gender.
They also report that participants' performance on the tests was influenced by how much they believed in the idea of free will, which the researchers define as the belief that a person is largely responsible for his or her own outcomes.
For example, conservatives who are more likely to embrace the idea of free will overwhelmingly agreed with statements like "Strength of mind can always overcome the body's desires" and "People can overcome any obstacles if they truly want to."
"Conservatives tend to believe they had a greater control over their outcomes, and that was predicting how they did on the test," said Joshua Clarkson, a consumer psychologist at the University of Cincinnati and the lead author of the paper.
There was, however, one instance when liberals outperformed conservatives on the test.
During one of the experiments, participants were given a fake research article that suggested believing in free will is an obstacle to achieving personal goals. The volunteers were asked to read it before taking the test.