People with a genetic predisposition for anxiety might be less likely to help others, a new study suggests.
Researchers found that lower engagement in prosocial behavior -- such as volunteering -- and higher social avoidance are associated with a variation in the serotonin transporter gene regulatory region.
"Previous research has shown that the brain's serotonin neurotransmitter system plays an important role in regulating emotions," study researcher Scott Stoltenberg, an associate professor at the University of Nebraska-Lincoln, said in a statement. "Our findings suggest that individual differences in social anxiety levels are influenced by this serotonin system gene and that these differences help to partially explain why some people are more likely than others to behave prosocially. Studies like this one show that biological factors are critical influences on how people interact with one another."
Of course, researchers noted that it's not just genes that influence whether someone is likely to help others; environment likely also plays some role. "The nature-versus-nurture debate is always interesting," study researcher Gustavo Carlo, a professor in the College of Human Environmental Sciences at the University of Missouri, said in the statement. "However, I think that in our contemporary models of human behavior, we are beginning to understand the interplay between biology and the environment."
The new findings are published in the journal Social Neuroscience and are based on gene analysis and self-reports of certain tendencies -- such as social avoidance and prosocial behavior -- of 398 undergraduate college students.
Recently, a study in the journal Neuron showed that brain gray matter may also be linked with how generous a person is. That study, conducted by researchers at the University of Zurich, showed that altruistic people may have more gray matter in the temporoparietal junction brain region.