Status 'determines brain's reactions to others'
Our brains react differently to others depending on how we view their social status, researchers say.
The Current Biology study found those who see themselves as being of a high status display more brain activity with those they think are equally elevated.
The researchers said behaviour was determined by how people saw those around them.
A British expert said first evaluations were crucial in determining how individuals related to each other.
It was already known from other studies that monkeys behave this way; changing behaviour dependent on how they perceived the other animal's position in the troop.
The 23 participants, who had varying levels of social status, were shown information about someone of higher status and information about someone of lower status.
The team used functional magnetic resonance imaging (fMRI) to measure activity in the ventral striatum, part of the brain's reward system.
People who viewed themselves as having a higher subjective socioeconomic status displayed greater brain activity in response to other high-ranked individuals, while those with lower status have a greater response to other low-status individuals.
Dr Caroline Zink, of the US National Institute of Mental Health, who led the study, said: "The way we interact with and behave around other people is often determined by their social status relative to our own, and therefore information regarding social status is very valuable to us.
"Interestingly, the value we assign to information about someone's particular status seems to depend on our own.
She added that socioeconomic status is not based solely on money, but can also include factors such as accomplishments and habits.
Dr Jane McCartney, a London-based chartered psychologist and a member of the British Psychological Society, said: "First evaluations are terribly important to everyone, whether it's to do with status, looks or money.
"It's about deciding if this person is of the same status, and what one needs to do ensure they know you are of an equal status and evaluating what role they may play in your life."
She added: "I should think there'll be an awful lot of evaluating going on at Westminster Abbey on Friday."