Activation of Brain Region Predicts Altruism
DURHAM, N.C. -- Duke University Medical Center researchers
have discovered that activation of a particular brain region
predicts whether people tend to be selfish or altruistic.
"Although understanding the function of this brain region
may not necessarily identify what drives people like Mother
Teresa, it may give clues to the origins of important social
behaviors like altruism," said study investigator Scott A.
Huettel, Ph.D., a neuroscientist at the Brain Imaging and Analysis
Results of the study appear Sunday, Jan. 21, in the advance
online edition of Nature Neuroscience and will be published in
the February 2007 print issue of the journal. The work was
funded by the National Institutes of Health.
Altruism describes the tendency of people to act in ways
that put the welfare of others ahead of their own. Why some
people choose to act altruistically is unclear, says lead study
investigator Dharol Tankersley, a graduate student in Huettel's
In the study, researchers scanned the brains of 45 people
while they either played a computer game or watched the
computer play the game on its own. In both cases, successful
playing of the game earned money for a charity of the study
The researchers scanned the participants' brains using a
technique called functional magnetic resonance imaging (fMRI),
which uses harmless magnetic pulses to measure changes in
oxygen levels that indicate nerve cell activity.
The scans revealed that a region of the brain called the
posterior superior temporal sulcus was activated to a greater
degree when people perceived an action -- that is, when they
watched the computer play the game -- than when they acted
themselves, Tankersley said. This region, which lies in the top
and back portion of the brain, is generally activated when the
mind is trying to figure out social relationships.
The researchers then characterized the participants as more
or less altruistic, based on their responses to questions about
how often they engaged in different helping behaviors, and
compared the participants' brain scans with their estimated
level of altruistic behavior. The fMRI scans showed that
increased activity in the posterior superior temporal sulcus
strongly predicted a person's likelihood for altruistic
According to the researchers, the results suggest that
altruistic behavior may originate from how people view the
world rather than how they act in it.
"We believe that the ability to perceive other people's
actions as meaningful is critical for altruism," Tankersley
The scientists suggest that studying the brain systems that
allow people to see the world as a series of meaningful
interactions may ultimately help further understanding of
disorders, such as autism or antisocial behavior, that are
characterized by deficits in interpersonal interactions.
The researchers are now exploring ways to study the
development of this brain region early in life, Tankersley
said, adding that such information may help determine how the
tendencies toward altruism are established.
C. Jill Stowe, a decision scientist in Duke's Fuqua School
of Business, also participated in the research.