A new study says people vote for pretty leaders.

Women running for political office not only need to be competent -- they gotta be hot too, according to a new study conducted by Northwestern University.

In a study that could potentially help justify spending $150K on makeup and clothing for Vice Presidential nominee Sarah Palin, scientists say men and women vote for female candidates partly on their looks.

Here are the results:

•For male candidates, the only thing that matters is competence, while female voters prefer men who seem both competent and approachable.

•For female candidates, both male and female voters are more likely to vote for candidates that were both competent and beautiful.

And the reasons why are personal:

•Experts say when weighing their vote, people cast their ballots for the person they'd most like to have a beer with. In other words, the person they identify with on a friendship level.

•And for young voters, the subconscious gut instincts they use in selecting a romantic partner are also used when choosing a world leader.