It is thought that first impressions are everything when it comes to speed dating, during which people decide on someones romantic potential in just a few seconds.
But its 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 peoples own individual preferenceshow 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 ODoherty, professor of psychology and one of the papers co-authors.
However, very little has been known about how this might work in real social interactions with real consequencessuch 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 raters 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 ODohertys lab and first author of the paper.
But thats not the only thing thats happening, Cooper added.
When some participants saw a person they wanted