Faye Flam in The Philadelphia Inquirer:
Neurobiologist and anthropologist Michael Platt of Duke University is studying differences in how the sexes respond to pictures in general. On average, his research shows, men will pay to see images of women. But you have to pay women to look at images of men!
Platt started with similar studies in monkeys. While most animals are indifferent to photos even of individuals in their own species, monkeys and apes respond to pictures much as humans do.
Rhesus macaques that Platt studied, for example, easily recognized the faces of familiar monkeys. And they liked some faces more than others, though the face wasn’t always the favorite part.
Platt found that male macaques strongly preferred to look at pictures of females’ rear ends and dominant males’ faces. They liked them enough to pay, by sacrificing a chance to get a treat. But you had to bribe those same monkeys with treats to persuade them to look at female macaque faces or the faces of subordinate males.