People love talking about themselves, brain scans show
Participants who talked about themselves showed signs of activity in the areas of the brain that are linked to value and motivation, said Diana Tamir, lead author of a study published in this week's issue of the Proceedings of the National Academy of Sciences.
"This helps to explain why people so obsessively engage in this behavior. It's because it provides them with some sort of subjective value: It feels good, basically," said Tamir, a graduate student in the Social Cognitive and Affective Neuroscience Lab at Harvard University.
Indeed, the researchers found that the regions of the brain that are activated by talking about oneself are also responsible for the thrills of food, sex, money and drug addiction, Tamir said.
The findings are more than a scientific curiosity, Tamir said, considering how much time people spend discussing themselves. By one estimate, 30 percent to 40 percent of your speech has to do with you.
"Self-disclosure is a behavior that we do all of the time, day in and day out: When you talk to people, they'll often talk about themselves," Tamir said. "On Twitter and Facebook, people are primarily posting about what they're thinking and feeling in the moment. This is one piece of evidence about why we may do that."
In the study, Tamir and a colleague conducted several experiments on subjects whose brains were scanned as they were told to do various things.
In one experiment, 78 participants alternately disclosed their own opinions -- about things like whether they preferred coffee or tea -- and judged the opinions of others whose photographs they looked at.
In another experiment, 117 people alternately talked about their personality traits (among other things, declaring whether they're "curious" or "ambitious") and those of the U.S. president at the time, either George W. Bush or Barack Obama.
The researchers found that certain parts of the brain were more active when people talked about themselves. In terms of monetary value, participants valued being able to share a thought as being worth about a penny, Tamir said: "We like to call it a penny for your thoughts."
So, why did evolution encourage humans to feel good when they talk about themselves? "We're doing some tests to see what larger role this behavior may play, whether people's motivation to self-disclose changes depending on their motivations to bond with someone," Tamir said. "Some studies show that the more you self-disclose to someone, the more you like them, the more they like you. It may have something to do with forming social bonds."
Paul Zak, a brain researcher and founding director of the Center for Neuroeconomics Studies at Claremont Graduate University, said the findings are "very convincing" and offer insight into human evolution.
"If a social creature did not disclose information, then other creatures might stop interacting with it," he said. "Animals do this with smells and movements, and humans do this with language. This study reveals how our brain evolved to motivate sociality, which is pretty cool."
To learn more about the brain, try Harvard's brain atlas.
Copyright © 2012 HealthDay. All rights reserved.