In a scientific landscape where “Survival of the fittest” is as accepted as biological fact, a certain group of humans behaving benevolently–altruists–has puzzled scientists for years. An altruist will go so far as to endanger their own self to help another, even a complete stranger.
A new study called Neural and cognitive characteristics of extraordinary altruists published in the US journal Proceedings of the National Academy of Sciences has shown that the seat of human altruism, and its opposite–psychopathy–appears to reside in the amygdala.
The researchers from Georgetown University in Washington knew they had to find participants who qualified as “extreme altruists”; they chose people who had donated kidneys to perfect strangers as the right fit for their study. Using fMRI, they scanned 19 healthy kidney donors, as well as 20 non-donors as a control group. The participants were shown images of faces expressing neutral, angry and fearful appearances, hypothesizing based on past studies that the altruistic group’s amygdalas would respond more sensitively to the fearful expressions. What they weren’t expecting was that the right side of the altruists’ amygdalas were 8 per cent larger than those of the non-donors.
Interestingly, a previous study has shown that the amygdala function appears inactive in the brains of people with psychopathic tendencies. Thus, this new research points to the amygdala as the seat of human compassion–or lack thereof.