In Andrew Leigh and Amy King’s paper on politicians’ beauty (pdf) they found that looks matter more for male candidates than female candidates.

In the paper, and in The Age’s report, they suggest that ‘dumb blonde’ stereotypes might lead voters to judge attractive women negatively:

“This may be because female beauty carries negative connotations in the minds of some voters,” said Dr Leigh.

Perhaps. But I think there is an explanation that fits better with what they have found makes a difference – that candidate attractiveness has most effect where the candidate is a challenger and where voters are older, poorer, and have low levels of education. What all this suggests is that attractiveness is used to choose between candidates when voters don’t have other more reliable sources of information to hand, because the challenger is previously unknown to them and/or they don’t know much about politics.

The Australian Election Survey suggests that women are less likely than men to have the political information they need to choose between candidates. In the 2004 Australian Election Survey, 24.2% of women rated their interest in politics as ‘not much’ or ‘none’, compared to 17.5% of men. Interest in the campaign itself was even lower, with 27.4% of women and 24% of men presumably going to the polling booth having absorbed very little information about any of the candidates.

Presuming that most people react more strongly to opposite-sex beauty than same-sex beauty, this means that there is a larger pool of people predisposed to using male beauty as a proxy than female beauty. It would explain why attractive men seem to influence the vote more than attractive women.