A new Northwestern University study has made some surprising discoveries about gender bias and voter behaviour. Researchers at the Chicago-area university have found that when it comes to winning elections, good looks matter, especially for women.

The study, titled "The Political Gender Gap," found that competence alone won't give women the winning edge in political contests. Instead, researchers say female candidates need to be both competent and attractive to win over voters.

"The results are quite startling," says Joan Chiao, a psychology professor and one of the study's lead researchers.

"One of the take home points is that campaign managers may have it right when it comes to (the importance of a candidate's) image," she told CTV.ca in a telephone interview from Evanston, Il.

Chiao said the recent controversy about U.S. vice presidential nominee Sarah Palin's wardrobe may not be such a trivial matter. The study indirectly suggests that the Republican Party may have made a good political investment when it spent $US150,000 on Palin's wardrobe in the month after she was put on the GOP presidential ticket.

The study asked participants to rate congressional candidates from the 2006 election on a seven-point scale, based on their pictures. They were asked to rate the candidates' competence, attractiveness, approachability and dominance. In a separate task, candidates were shown a pair of candidates from the 2006 congressional race and asked to choose one of the two as president of the U.S.

The study found that:

  • Voters perceived the faces of male politicians as more competent and dominant relative to female politicians.
  • Female politicians were perceived as more attractive and approachable relative to males.
  • Candidates who were perceived as more attractive by men were more likely to win votes in the actual Congressional election.
  • Gender stereotypes may bias voters to value male politicians over female politicians because they possess facial features associated with effective leaders.

Chiao says men value a candidate's attractiveness, as well as competence, while women value approachability. These findings suggest that unconscious factors are at play for both sexes when voters cast their ballots. But the study also found that good looks were almost all that mattered in predicting men's votes for female candidates.

"We think this is remnant of the legacy of evolution," Chiao said. "It's very possible that voters apply gut instincts unconsciously."

Chiao said that elections are a relatively recent phenomenon and, therefore, voters may still rely instinctively on factors other than a candidate's platform, intelligence, or skills. But that doesn't mean that female politicians will always face an unspoken attractiveness test by voters.

"I think there is some interesting data that shows that exposure to female politicians in high ranks tend to reduce these gender stereotypes ... so it's possible that voters come to reduce their reliance on cognitive shortcuts," she said.

"The Political Gender Gap: Gender Bias in Facial Inference that Predict Voting Behavior" was published Friday in the open-access journal PLoS ONE.