Did you do a good turn today? If you feel compelled sometimes to do something particularly altruistic, you may have a particularly well-developed amygdala.
(Painting, “A Good Deed Is Never Forgotten,” by Pierre Nicolas Legrand (1758-1829), in the Dallas Museum of Art. Image by Rodney, on Flickr under Creative Commons.)
Researchers at Georgetown University have been delving into the brains of people who are particularly altruistic — even studying people who have donated kidneys to complete strangers — as noted in The Biology Of Altruism: Good Deeds May Be Rooted In The Brain. Using functional MRI scans, principal investigator Abigail Marsh examined the structures of their brains and their brain activity while they took tests and looked at specific images. For example, they showed subjects “pictures of different facial expressions, including happiness, fear, anger, sadness and surprise.”
Most of the tests didn’t find any differences between the brains of the altruistic donors and the people who had not been donors. Except, Marsh says, for a significant difference in a part of the brain called the amygdala, an almond-shaped cluster of nerves that is important in processing emotion.
… The amygdala was significantly larger in the altruists …. Additionally, the amygdala in the altruists was extremely sensitive to the pictures of people displaying fear or distress.
The more we learn about the brain, the more remarkable it is! This finding makes sense to me, since altruism depends, at least in part, on the ability to imagine oneself in another person’s dire circumstances, and then to act to change those circumstances.
I found this part particularly interesting:
These findings are the polar opposite to research Marsh conducted on a group of psychopaths. Using the same tests as with the altruists, Marsh found that psychopaths have significantly smaller, less active amygdalas. More evidence that the amygdala may be the brain’s emotional compass, super-sensitive in altruists and blunted in psychopaths, who seem unresponsive to someone else’s distress or fear.
So if altruism is your default state, it may be because you have a very active amygdala — a highly tuned “emotional compass.” And for those of us who are not very altruistic, it may be that we have some traits in common with … psychopaths. That’s not the most comforting thought, but perhaps this will help: Aristotle taught that we become virtuous by developing and practicing the habit of being virtuous, and we have the Golden Rule (e.g., Matthew 7:12) as one guideline we can use as we do so.
So, do a good turn today!
by 
So, my brother is completely strange. Does that count? 😛
Of course it does!
G