New scans have shown that when judging who's hot or not, brain regions associated with higher functions, such as understanding the intentions of others and self-awareness, light up.
The study implies that when someone casts meaningful looks at an attractive stranger it may be a sign of some of the most sophisticated thoughts a person can have.
In the research, neuroscientist Stephanie Ortigue of Syracuse University and Francesco Bianchi-Demicheli of Geneva University Psychiatric Center found that people making quick judgments about others' sexiness are using regions of the brain associated with higher functions, reports National Geographic News.
Moreover, the scientists found that, higher brain regions activate before they receive information from the visual cortex or the brain's emotional centers.
"We've found the brain knows who we desire and when we desire before we are aware of it," Ortigue said. "It's very unconscious."
For their study, published in 2008 in the journal NeuroImage, Ortigue and Bianchi-Demicheli wired a group of 13 healthy adults so the scientists could record brain activity via a technique called high-density EEG neuroimaging.