Last fall, two University of South Florida psychologists subjected 133 undergraduates to a grueling test, requiring them to stare at photos of both Angelina Jolie and Sarah Palin.

In each case, the more attention the students paid to the women’s appearance, the less competent they judged the pair to be. And in Palin’s case, the less likely they were to vote for her.

Here’s the kicker: In Palin’s case, her looks only affected Republicans and independents. Not Democrats.

And gender made no difference. An article on the study has just been published in the Journal of Experimental Social Psychology. It’s hidden behind an Internet pay screen, and we’re cheap, so we haven’t seen it.

But it was a worth a phone call with Jamie Goldenberg, an associate professor over at USF who co-authored the article with Nathan Heflick. The two researchers had theorized a correlation between looks and competence.

“We were shocked that we got any movement on the voting,” Goldenberg said Thursday. “It didn’t affect Democrats. They were all going to vote for Obama no matter what. It was only Republicans and independents who were moved.”

Basically, the students were asked to write about each woman — whether about her accomplishments as a person, or about her looks. “What we found is that in both cases, whether they wrote about Palin or Angelina Jolie, when they wrote about her appearance rather than the person, they evaluated her to be less competent, less fully human. And in the case of the Palin prime, they were less likely to vote for the McCain-Palin ticket,” Goldenberg said.

The study was done before the October news about GOP expenditures on Palin’s wardrobe, which dampened the vice presidential nominee’s poll numbers. The Internet buzz on this study has abbreviated the results by declaring sexiness to be a handicap in politics. This isn’t quite the right reading, Goldenberg said.

She not denying that attractiveness contributed. “Presumably that played a role,” the professor said. What the study actually found was that the more attention paid to a subject’s appearance, the less competent she was judged. In other words, ugliness could be just as diverting.

“We haven’t controlled for all the variables. It could be if someone is super competent it wouldn’t have the same effect. But what we found is that it was the act of focusing on the appearance,” she said. So the lesson isn’t for Palin to acquire a certain frumpiness before the 2012 presidential campaign — but to establish bona fides that outshine it.

“You don’t want to do things to draw attention to your appearance above and beyond your person — who you are. You don’t want to be reduced to an object,” Goldenberg said.Now, as to the matter of whether the Palin effect might apply to men, Goldenberg said she wasn’t sure. “But the fact is that women are more often targeted for objectification. So the phenomenon should apply to women more. Even if you focus on a man’s appearance, it may be done in a different way,” she said.