Princeton University Psychologist Susan Fiske measured brain activity of straight men while showing them various photographs of women with skimpy clothing. She has found that the part of the brain most reactive to the photographs is the same part associated with the intention to use a tool.

Beyond acting on a wish, Fiske argues, the scans demonstrate a less-than-humanistic approach to the fantasy.

Fiske also asked each participant to fill out a questionnaire of her own design to measure how sexist each man was. She found that the more sexist among them had demonstrably lower activity in the prefrontal cortex, the area associated with human interaction.

This is usually “a very reliable effect,” says Fiske, even when only thinking about people, and not actually interacting. The lack of activity in the prefrontal cortex indicates a lack of empathy with the photographed women, even more than when the same men were shown photographs of women fully clothed.