November 13, 2012
How The Brain Affects Quick Judgments In Social Settings
April Flowers for redOrbit.com - Your Universe Online
We make snap judgments about other people all the time, whether we like to admit it or not. In speed dating, this is especially true because we are deciding someone's romantic potential in relatively few seconds. How we make those fast decisions is not very well understood, however.A research team from the California Institute of Technology (CALTECH) and Trinity College, Dublin has found that people make such speed-dating decisions based on two factors that are related to activity in two distinct parts of the brain.
It's not very surprising that the first factor affecting the number of dates a person gets is physical attractiveness. The second factor is a bit less obvious, involving people's personal preferences. For example, how compatible a potential partner may be.
The findings, published in the November 7 issue of Journal of Neuroscience, are among the first to look at what happens in the brain when people make rapid-judgment decisions that carry real social consequences.
"Psychologists have known for some time that people can often make very rapid judgments about others based on limited information, such as appearance," says John O'Doherty, professor of psychology and one of the paper's coauthors. "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."
The study recruited 30 heterosexual males and females who were placed into a functional magnetic resonance imageing (fMRI) machine. They were shown pictures of potential dates of the opposite sex and given four seconds to rate, on a scale from 1 to 4, how much they would want to date that person. They were shown as many as 90 faces, then outside the fMRI, they were asked to rate the same faces again — this time on attractiveness and likeability on a scale from 1 to 9.
The particpants later took part in an actual speed dating event where they spent five minutes talking to some of the potential dates they had initially rated in the fMRI machine. They listed the ones they wanted to see again, and just like a real speed dating event, they were given each other's contact information if there was a match.
Unsurprisingly, the team found that people who were highly rated on attractiveness were the ones who got the most date requests. Seeing an attractive face is associated with activity in a region of the brain known as the paracingulate cortex, a part of the dorsomedial prefrontal cortex (DMPFC). The DMPFC is an important area for cognitive control decision making. In particular, the paracingulate cortex has been shown to be active when the brain is comparing options, like which face is more attractive.
Jeff Cooper, former postdoctoral scholar in O'Doherty's lab, said that the phenomenon was fairly consistent across all participants. This shows that nearly everyone considers physical attraction when judging a potential romantic partner. This judgment is correlated with activity in the paracingulate cortex.
Cooper says that's not the only thing happening, though. More activation was shown in the rostromedial prefrontal cortex (RMPFC) when participants saw a person they wanted to date, but who was not rated as very desirable by everyone else. The RMPFC is part of the DMPFC, but sits farther in front than the paracingulate cortex and has been associated with consideration of people's thoughts, comparisons of oneself to others, and perceptions of similarities with others. In addition to physical attractiveness, the study finds, people consider individual compatibility.
Good looks remain the most important factor in determining date requests, however, a person's likeability — as perceived by other people — is also important. Likeability serves as a tie breaker if two people are rated equal on attractiveness and a more likeable potential date was more likely to be asked for a date.
"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 says.
The researchers have not followed up on the dating couples, although Cooper says at least a few couples were still together after six weeks. The study focused solely on the neural mechanisms behind rapid judgments, they were not concerned with the long-term romantic success of the dating event.