Be generous, it will make you happy! This could be the conclusion of a study carried out by an international team of neurobiologists from the universities of Lübeck (Germany), Chicago (United States), and Zurich (Switzerland). Using magnetic resonance imaging (MRI), the researchers discovered a neural link between generosity and happiness. How were they able to isolate this relationship in the brain?

Among the studies seeking to uncover the motives for generous behavior, it’s undoubtedly those in psychology that, since the year 2000, have put forward the most interesting hypothesis: what if altruism and generosity made us happy? While the positive emotion induced by generous behavior is an obvious motivation, no neuronal mechanism linking generosity and happiness had ever been identified and studied. Soyoung Q. Park’s team has now done just this by developing an experimental protocol designed to induce generous behavior.

To begin, the team welcomed volunteers in their laboratory after they had completed a subjective questionnaire to assess happiness. They were then randomly assigned to the experimental or control group. The 50 participants (11 men, average age = 25.6 years) were all told they would receive 25 Swiss francs (about 26 dollars) each week for one month. Those in the experimental group had to spend the money on other people of their choice (for example by offering them gifts or inviting them to dinner); those in the control group had to spend their money on themselves. In both cases, the participants were asked to write how they planned to spend the money.

Then, while brain activity was being measured by fMRI, each participant was subjected to a decision-making task in which they could behave more or less generously. Each participant selected a person to whom they wanted to give a gift (for the experimental group, this person could not be one of the future beneficiaries of the 26 dollars). Several questions with multiple options were presented to the subject, such as: in order to give a gift worth 18 Swiss francs, do you agree to pay the price of 25 Swiss francs?

The scientists hypothesized that the subjects in the experimental group would behave more generously and report greater happiness than the control group; they also expected to see functional interactions between brain areas related to generous behavior (the tempo-parietal junction, TPJ) and happiness (the ventral striatum).

The results confirm these hypotheses: even before the gifts were given, the group that promised to use their money to benefit others reported a higher level of happiness and was also more generous during the decision-making test. During the test, generous decisions activated the TPJ more in the experimental group than in the control group and differentially modulated connectivity between the TPJ and the ventral striatum. The study thus highlights the connection between generosity and happiness in the brain.

And what if the happiness generated by generosity motivated more generosity?