Empathy is key for politicians who want to win over potential voters, according to a recent study.

Researchers from the University of Toronto found that arguments based on a political opponent's moral principles, rather than one's own, have a much better chance of success. They decided to investigate the idea after watching the increasing polarization in American politics.

"We were trying to figure our ways to overcome the polarization," researchers Matthew Feinberg, who teaches organizational behavior at the University of Toronto's Rotman School of Management, said in a statement.

For the study, researchers ran a series of experiments that had participants come up with arguments of their own for someone of the opposite political viewpoint.

The found that both groups were extremely poor at developing arguments that would appeal to their political opposite, even when specifically asked to do so. They also found that some participant in both camps actually attacked the morality of those they'd been asked to convince.

"Most people are not very good at appealing to other people's values," Feinberg said.

Liberals asked to appeal to conservatives for support of same-sex marriage had only a 9 percent success rate in developing arguments based on conservative values of loyalty, authority or purity (such as, "our fellow citizens deserve to stand alongside us ..."). Only 8 percent of conservatives came up with liberal-friendly arguments about why English should be adopted as the official language of the United States, based on principles of fairness and protection from harm (e.g. "there will be less discrimination").

Conservatives were more inclined to support universal health care when presented with purity-based arguments that more uninsured people might lead to more disease spread. Liberals showed an uptick in support for higher military spending, when shown an argument based on the principle that the military and the employment opportunities it provides help to reduce inequality.

"Instead of alienating the other side and just repeating your own sense of morality, start thinking about how your political opposition thinks and see if you can frame messages that fit with that thought process," Feinberg said.

The findings are detailed in Personality and Social Psychology Bulletin.