Why is it that some people are selfish (and just teenagers, for whom it’s a prerequisite) and others are selfless? I would have guessed that these traits are learned, a product of one’s family, school, and community, but a new study in the Proceedings of the National Academy of Sciences suggests that “extraordinary altruists,” which is defined as people who do extreme good deeds for others, such as donate a kidney to a stranger in need, actually have different neural and cognitive characteristics than the rest of us.
For the study, researchers from Georgetown University and the University of Washington, but who had not demonstrated such extraordinary altruism, also participated in the study as a control group. Then, the researchers showed the participants images of people with specific facial expressions demonstrating fear, anger, or nothing at all (neutral). Then they used an MRI to map their brain activity.
The scientists paid particular attention to the responses to the images that expressed fear, which in previous studies have evoked empathy and compassion in people identified as altruistic. The recent study confirmed these findings, as a group of kidney donators displayed increased activity in their amygdalas, which is the part of the brain involved in emotion. But the more interesting—and, I think, suspect—part of the finding is that the amygdala’s right side was 8 percent bigger in the donors than in the control group. Given that the groups were so small—19 and 20, respectively—I’m not sure it’s possible to tell whether this result is a product of causation or correlation. There could very well be other explanations for the amygdala size among the altruists.
The same group did a study a year ago that examined a nearly polar opposite group of people: psychopaths. That study involved measuring the brain activity of 14 teenagers who displayed characteristics of psychopathology as they looked at images of people getting injured. As one might guess, they were less affected by these images, and brain scans revealed that the right side of their amygdalas was smaller than that of the control group.
Thus, the researchers conclude that the amygdala may shape one’s tendency toward selflessness, and that the region might serve as a moral regulator. I’m not quite convinced it’s that simple—I think there must be other explanations for the development of altruism, including altruism in animals—or that the relationship is causal, but the researchers plan on conducting additional studies focusing on subjects’ response to other indications of pain, sadness, and compassion-eliciting states. At the same time, mad scientists trying to create a utopia on Earth are thinking of ways to artificially inflate the right side of the population’s amygdalas.