There is a strong relationship between a voter's politics and his personality, according to new research from the University of Toronto.

Researchers at UofT have shown that the psychological concern for compassion and equality is associated with a liberal mindset, while the concern for order and respect of social norms is associated with a conservative mindset.

"Conservatives tend to be higher in a personality trait called orderliness and lower in openness. This means that they're more concerned about a sense of order and tradition, expressing a deep psychological motive to preserve the current social structure," says Jacob Hirsh, a post-doctoral psychology student at UofT and lead author of the study.

The study, which appears in this month's Personality and Social Psychology Bulletin, may even lend some legitimacy to the term, 'bleeding-heart-liberal.'

"Our data shows that liberalism is more often associated with the underlying motives for compassion, empathy and equality," says Hirsh.

Researchers asked more than 600 participants from Canada and the US to classify their politics as either small-L liberal or small-C conservative instead of identifying with a particular political party. They then administered a personality test to determine the participants' personality traits and their relationship to political preferences.

Hirsh's work contributes to accumulating evidence suggesting political behaviour is motivated by underlying psychological needs. "We are beginning to understand the deeper motivations that are involved in determining an individual's political leanings," says Hirsh. "While everybody has the same basic motivational architecture, the relative strength of the underlying systems varies from one person to the next. If concerns for order and equality are relatively balanced, the individual is likely to be politically moderate; as either motive grows stronger than the other, political preferences move further to either end of the spectrum."

"People's values are deeply embedded in their biology and genetic heritage," says UofT Professor and co-author Jordan Peterson. "This means you have to take a deeper view of political values and morality in terms of where these motives are coming from; political preferences do not emerge from a simple rational consideration of the issues."

Peterson argues that in order to maintain a functioning society, both types of political motivation are required.

"The fact that variability still exists in these motivational systems, from an evolutionary perspective, means that neither one is sufficient on its own. There are costs and benefits to each political profile and both appear critical to maintaining an effective balance in society."