The first gene linked to altruistic behavior has been identified by Israeli psychologists who believe it boosts receptors for the neurotransmitter dopamine, which gives the brain a good feeling.
The discovery of the gene variant on chromosome No. 11 is reported in the advance on-line edition of the journal Molecular Psychiatry (nature.com/mp) by Prof. Richard Ebstein, a psychologist, and colleagues at the Hebrew University and Herzog Memorial Hospital in Jerusalem. The “scientific correspondence” will appear in the printed journal in a month or so.
Ebstein, who headed a team that in the 1990s discovered a “risk-taking gene,” told The Jerusalem Post on Wednesday that the source of altruism—in which someone sacrifices his own interests to benefit others—has been an important question in evolutionary theory for many years.
Even Charles Darwin dealt with it, he said. One would not expect altruism to have an evolutionary benefit because the altruistic person promotes other people’s survival by taking risks that could endanger his own. Ebstein discussed the matter with his students in an evolutionary psychology course and then launched the genetic study.
Higher animals can show altruistic behavior, said Ebstein, but it is almost always for members of their family, whom they identify by odors and other signals. But altruistic behavior is very prominent in human behavior.
Ebstein and colleagues took blood samples from 354 families with multiple siblings and asked them questions to rate them on the Selflessness Scale, a measure of altruistic behavior. Their answers were completely anonymous, thus they did not benefit from describing themselves. “Depending on self-reporting could present some problems, but we are working to confirm our findings by conducting economic games with reward and punishment to see if people display altruistic behavior and then to test them for the gene variant.”
He is also considering the possibility of looking for the gene in groups of people who clearly exhibit altruistic behavior, such as Yad Sarah, Magen David Adom or Zaka (Disaster Victims Identification) volunteers.
Ebstein said about two-thirds of the random sample carry the altruism gene. Interestingly, the risk-taking gene, which is linked to a tendency for taking drugs, smoking and other dangerous behavior, is a different—or opposite—variant of the altruism gene. Instead of promoting dopamine expression, the risk-taking gene variant reduces it.
“This may mean that people who don’t get enough dopamine in their brains seek out drugs or other such means to get a ‘high,’” Ebstein suggested. “Dopamine probably plays a key role in pro-social behavior. People with the altruism gene may do good works because they get more of a thrill out of their good works.”
Ebstein is certain that this is only the first altruism gene, and that several others exist. “I think genes have only half of the influence on altruistic behavior, with the rest involving environmental factors, such as education.”
In this study, said Ebstein, “we did not fine this altruism gene more common in women than in men,” despite their roles as caregivers and their prominence in caregiving professions.
Anorexic women score high on the Selflessness Scale. “They may take altruism to an extreme, eating minimally to ‘sacrifice’ food for other people.”
Religiously observant people tend to score higher on the scale, he continued, apparently due to the value put on altruism and doing good deeds in religious education and religion itself.