Whether you are a conservative or a liberal may indicate whether or not you will stick to a diet. According to a paper published in Proceedings of the National Academy of Sciences, conservatives have more self control than liberals.

Researchers conducted three tests that included more than 300 volunteers, and found that people who self-identify as conservatives have more control regardless of other factors, such as gender, race, or socioeconomic status.

The study found that conservatives showed greater self-control on tasks that test persistence and attention.

"This study is an attempt to take a contemporary approach to the classic picture of how liberals and conservatives explain behavior and the consequences of those explanations for self-control," said Josh Clarkson, assistant professor at the University of Cincinnati and lead author of the study.

Political conservatives are often seen to be reflecting a Protestant work ethic, and attribute their success more to hard work and perseverance rather than factors beyond their control, such as birth or rank in society.

"If you believe that you're responsible for your own actions, or the outcome of your own actions, you're actually better able to engage in self-control, which would suggest conservatives should demonstrate a greater capacity for self-control," Clarkson said.

To test the hypothesis, participants took a questionnaire that determined whether they believed in free will. Statements included remarks such as "people have complete control over decisions they make," "people can overcome obstacles if they truly want to," and "criminals are responsible for the bad things they do."

The questionnaire results corresponded to the political beliefs of the participants, and those who responded the strongest also performed better on tasks that measured self-control.

Despite the clear distinction in self-control between liberals and conservatives, the results aren't necessarily permanent. If a conservative can be convinced that the belief in free will leads to negative outcomes, self-control can be undermined.

When study participants were given fake test results that showed free will could be detrimental to self-control, the effects were reversed, and liberals performed better.