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New research shows that small acts of generous behavior cause the brain of the person giving to light up with a “warm glow” marked by increased levels of . The brain imaging data also showed that Scrooge-ish people—who acted solely out of self-interest—were less happy and did not emit a warm glow in the fMRI. The findings of this University of Zurich (UZH) study, “A Neural Link Between Generosity and Happiness,” were published online ahead of print July 11 in the journal Nature Communications.

Civil society benefits when all of us are cooperative and generous in some way. From an evolutionary perspective, a 2016 Canadian study, "Altruism Predicts Success in Humans," found that we are hardwired to be attracted to and turned off by selfishness and greed. Generous behavior appears to be a magnet that attracts potential mates to one another like moths to a flame.

Additionally, previous research has shown that participants who spent money on others reported higher levels of happiness compared to those who only spent money on themselves. However, because generous behavior can be costly to one’s own resources, standard economic theories and "bean counters" have traditionally failed to explain what motivates generous behavior.

Therefore, neuroeconomists from UZH recently collaborated with an international team of researchers to design a -based experiment that could illuminate how small acts of generosity light up the brain using functional magnetic resonance imaging (fMRI). Until this study, human neuroimaging studies haven’t investigated brain areas associated with generous behavior and happiness simultaneously.

The UZH research team led by Philippe Tobler and Ernst Fehr from the Department of Economics were specifically interested in identifying what degree of generosity was necessary to light up someone's brain inside the fMRI with what behavioral economists call "warm glow."

Before the experiment began, some participants were asked to verbally commit to be generous with others. As part of the game, this group was also asked to accept slightly higher costs in order to do something nice for someone else. The control group was given instructions to self-deal and behave generously only towards themselves and to be stingy with everybody else. Then, all study participants were given a “slush fund” of money that they could spend on someone else or spend on themselves.

Throughout various aspects of this experiment, a series of decisions were made concerning generous or selfish behaviors as participants were observed in the fMRI.

The researchers were able to pinpoint specific brain areas that lit up during times of generosity. Altruism and overcoming egocentricity have previously been correlated with functional activity and structural properties of the temporoparietal junction (TPJ). As would be expected, the TPJ lit up when people displayed prosocial behaviors and generosity by giving to others during the game. Reward-related brain areas such as the ventral striatum and the orbitofrontal cortex (OFC) are correlated with feeling good and also lit up when someone was being generous.

Across the board, those who displayed generosity towards others showed activity in brain areas associated with happiness and feeling rewarded. On the flip side, those who kept all of the money for themselves showed significantly less neural activity in these brain areas and did not emit a warm glow.

Very Small Amounts of Generosity Can Give Your Brain a "Warm Glow"

One of the most surprising aspects of this study is that the amount of generosity did not correlate directly with the degree of someone's happiness or contentment. Very small amounts of generous behavior could elicit the warm glow of feeling happy. "You don't need to become a self-sacrificing martyr to feel happier. Just being a little more generous will suffice," Philippe Tobler said in a statement.

Interestingly, the researchers also found that simply making a verbal commitment to behave more generously in the future activated altruistic areas of the brain and intensified the warm glow within brain areas associated with positive emotions. Tobler commented on this aspect of the study: "It is remarkable that intent alone generates a neural change before the action is actually implemented. Promising to behave generously could be used as a strategy to reinforce the desired behavior, on the one hand, and to feel happier, on the other."

Undoubtedly, most of us know from first-hand experience that doing something kind-hearted or generous for someone else gives you a "warm fuzzy" feeling that the researchers observed using high-tech fMRI brain imaging. Nevertheless, it’s nice to have empirical evidence that reminds us all that even minuscule amounts of day-to-day generosity can trigger neurobiological changes in your brain that are clinically proven to increase happiness and contentment.

Remember: Small acts of generosity create the ultimate win-win by making someone else's day a little bit brighter and giving your brain a warm glow, too.