But it’s more than just whether someone is hot or not, according to a new study.
Researchers at the California Institute of Technology (Caltech) have found that people make such speed-dating decisions based on a combination of two different factors that are related to activity in two distinct parts of the brain.
Unsurprisingly, the first factor in determining whether someone gets a lot of date requests is physical attractiveness. The second factor, which may be less obvious, involves people’s own individual preferences—how compatible a potential partner may be, for instance.
The study is one of the first to look at what happens in the brain when people make rapid-judgment decisions that carry real social consequences, the researchers said.
“Psychologists have known for some time that people can often make very rapid judgments about others based on limited information, such as appearance,” said John O’Doherty, professor of psychology and one of the paper’s co-authors.
“However, very little has been known about how this might work in real social interactions with real consequences—such as when making decisions about whether to date someone or not. And almost nothing is known about how this type of rapid judgment is made by the brain,” he stated.
In the study, 39 heterosexual male and female volunteers were placed in a functional magnetic resonance imaging (fMRI) machine and then shown pictures of potential dates of the opposite sex. They were given four seconds to rate, on a scale from 1 to 4, how much they would want to date that person.
The researchers found that the people who were rated as most attractive by consensus were the ones who got the most date requests.
Seeing someone who was deemed attractive (and who also ended up with more date requests) was associated with activity in a region of the rater’s brain called the paracingulate cortex, a part of the dorsomedial prefrontal cortex (DMPFC), which is an important area for cognitive control and decision making. The paracingulate cortex, in particular, has been shown to be active when the brain is comparing options.
This phenomenon was fairly consistent across all participants, said Jeff Cooper, a former postdoctoral scholar in O’Doherty’s lab and first author of the paper.
“But that’s not the only thing that’s happening,” Cooper added.
When some participants saw a person they wanted to date—but who was not rated as very desirable by everyone else—they showed more activation in the rostromedial prefrontal cortex (RMPFC), which is also a part of the DMPFC, but sits farther in front than the paracingulate cortex.
The RMPFC has been previously associated with consideration of other people’s thoughts, comparisons of oneself to others, and, in particular, perceptions of similarities with others. This suggests that in addition to physical attractiveness, the researchers say, people consider individual compatibility.
While good looks remains the most important factor in determining whether a person gets a date request, a person’s likeability—as perceived by other individuals—is also important.
“Our work shows for the first time that activity in two parts of the DMPFC may be very important for driving the snapshot judgments that we make all the time about other people,” O’Doherty said.
The study has been published recently in the Journal of Neuroscience.