Brother, Can You Spare Some Change?

(Editor’s note: This article is from a past issue of Brain World magazine. If you enjoy this article, please consider a print or digital subscription!)

The winter holidays are upon us once again, a time for parties, family and togetherness — and a time for peace and giving; which is no wonder why charities need and request more contributions during the holidays. Will you be one to donate?

The answer may lie in your genes.

Researchers at the University of Bonn can likely predict whether you’re the altruistic type. The study, “Investigating the Genetic Basis of Altruism: The Role of the COMT Val158Met Polymorphism,” published in Social Cognitive and Affective Neuroscience, revealed a minute change in a particular gene that is associated with significantly higher altruistic behavior. People with this change were shown to donate twice as much to charity, on average, than those without. In the study, Dr. Martin Reuter and his fellow researchers administered a computer retention test to approximately 100 participants, who were asked to memorize a series of numbers and then repeat them as correctly as possible afterward. As a reward for participating, they received a sum of five euros. When the study was over, the participants had the option to keep their money or donate any portion of it to a charitable cause. They were told that the donation would be made freely and anonymously, though researchers behind the scenes were able to keep track of donations.

Participants were also asked, before the study commenced, to undergo a cheek swab. Researchers were able to extract DNA for genetic analyses from the cells sampled. The focus was on one gene — the COMT (catechol-O-methlytransferase) which controls the catechol-O-methyltransferase enzyme in its functioning. This enzyme is used to metabolize catecholamines, which inactivate certain messengers in the brain. It is also heavily linked to dopaminergic and adrenergic/nonadrenergic neurotransmission, or endporphins. COMT functions by metabolizing dopamine and freeing receptors in the brain for the binding of endorphins to the u-opioid receptors, which ultimately, is also known to lead to pain relief. The more potent the COMT enzyme that is functioning in the body, the more dopamine will be metabolized, and more endorphins are able to bind.

Furthermore, there are two variants of the COMT gene: COMT-Val and COMT-Met. The difference varies by just a single amino acid, and both versions are present in equal amounts in the population. But here’s the thing: The enzyme associated with the COMT-Val variants works up to four times more effectively at inactivating dopamine in the brain.

Researchers found through the study that by virtue of having the COMT-Val gene variation, a person would donate twice as much money on average as would someone with the COMT-Met difference. Data has also confirmed that dopamine is involved in controlling social behavior in animals and humans. Thus, the messenger, together with the substances such as the neuropeptide vasopressin, influence bonding and positive emotionality. While researchers were aware that altruistic behavior is hereditary, this is the first time that there has been a clear distinction in determining a specific gene.

Alongside these findings linking heredity and altruism, scientists have also questioned where exactly altruism originates in the brain. In a study from Duke University, neuroscientist Scott Huettel and his colleagues at the Brain Imaging and Analysis Center found a connection between altruism and the posterior superior temporal cortex (pSTC) of the brain. The pSTC is concerned with anticipating the intentions and activities of other people. According to Huettel, this portion of the brain has to do with perceiving stimuli in an environment that could impact others — a crouching tiger about to jump on a fellow hunter, for example.

In the study, researchers used functional magnetic resonance imaging (fMRI) to scan the brains of 45 volunteers while they either played a computer game or watched the computer play the game on its own. In both situations, successful playing of the game earned money for a charity that the participant had chosen. To help measure their altruism in real-world situations, the volunteers also underwent a questionnaire about how often they engaged in helping behaviors for others.

The fMRI scans revealed that the pSTC was more activated while participants watched the computer play the game, rather than when they were playing it themselves, because they were perceiving an action and trying to interpret social relationships. Researchers then characterized the participants as more or less altruistic, based on their responses to questionnaires, and compared the participants’ brain scans. These data indicated that increased activity in the pSTC strongly predicted a person’s likelihood for altruistic behavior, and suggests that this behavior may originate from how people view the world, rather than how they act in it.

“Our findings are consistent with a theory that some aspects of altruism arose out of a system for perceiving the intentions and goals of other,” said Huettel. “To be altruistic, you need to see that the people you’re helping have goals, and that your actions will have consequences for them.”

Huettel also agrees that there are multiple mechanisms that contribute to altruism, which can be seen in another study linking selfless behavior to the cerebral cortex — the outer layer of the brain that serves highly evolved cognitive functions, such as thought, judgment, and selfawareness.

Jordan Grafman, Ph.D., and his team of researchers published a study in the Proceedings of the National Academy of Sciences that used fMRI on a group of volunteers who had the option to anonymously donate to or oppose real charitable organizations related to major societal causes. A computer presented each charity to the subjects in series and gave them the option to donate, to oppose a donation, or to receive a payoff and potentially walk away with a pot of $128 — which was their initial gross pay. Sometimes, the decision to donate or oppose was costly, calling for subjects to take money out of the pot.

Researchers found that a similar pattern of brain activity was seen when subjects chose either to donate or take a payoff. Both of these decisions were associated with heightened activity in parts of the midbrain, a region deep in the brain that plays a key role in primal desires (hunger, sex, etc.), and the satisfaction of these desires.

Grafman continued by focusing his findings on the subjects that donated, or opposed donation, at a cost to themselves. In these individuals, the anterior prefrontal cortex lit up, an area of the brain toward the forehead and responsible for decision making and higher judgment. Furthermore, when Graman and his team asked subjects to rate their charitable involvement in everyday life, he found that those with the highest ratings of involvement also had the highest level of activity in the prefrontal cortex.

Taken together, these lines of evidence reinforce the notion that something about the act of putting others before yourself is linked to general mammalian neural systems of reward, social attachment, and even our genetics.

(Editor’s note: This article is from a past issue of Brain World magazine. If you enjoy this article, please consider a print or digital subscription!)

Be the first to comment

Leave a Reply

Your email address will not be published.