Summary: A new study reveals a neurobiological reason behind why we feel happy when we are being generous. Researchers discovered the connectivity between the temporal parietal junction and ventral striatum, an area of the brain associated with happiness, was enhanced in people who committed to generosity.

Source: Northwestern Medicine.

A new study finds that people who pledged to practice generosity showed greater increases in self-reported happiness — a connection that correlated on a neural level with changes in key brain activity.

The paper, published in Nature Communications and led by investigators at the University of Zurich in Switzerland, was co-authored by Thorsten Kahnt, PhD, assistant professor of Neurology in the Division of Comprehensive Neurology.

"There have been reports that people who spend money on others are happier, but it was always unclear why that is the case," Kahnt said. "This paper reveals the neural mechanism for why these two concepts are related."

In the experiment, the investigators told 50 participants that they would each receive 25 Swiss francs (about $25 American dollars) every week, for four weeks. The participants were then randomly assigned to one of two groups: a control group, where they committed to spending the money on themselves, or an experimental group where the participants committed to spending the money on other people.

Next, all the participants completed a separate task where they were asked to make decisions that either benefited themselves or others. While doing so, their brain activity was measured using functional magnetic resonance imaging (fMRI).

The investigators found that participants who had been previously assigned to be more generous with their money also ended up making more generous choices on the unrelated decision-making task, compared to the control group. Further, those in the generosity group also reported greater levels of happiness after the experiment was over.

Importantly, this connection between generosity and happiness corresponded with fMRI findings.

The scientists discovered that the experimental group showed significantly increased activity in an area of the brain called the temporo-parietal junction (TPJ) when making generous decisions, as compared to the control. The TPJ is generally associated with empathy and social cognition.

First, we informed the participants that we would send them money for the next 4 weeks (25 Swiss francs per week). We asked half of the participants to commit to spending this money on other people (experimental group) and half of the participants to commit to spending the money on themselves (control group). In addition, we assessed the participants’ subjective happiness upon their arrival at the laboratory (T1), that is, before they had made the commitment, and after scanning, that is, at the end of the experiment (T2). NeuroscienceNews.com image is credited to Kahnt et al./Nature Communications.

Further, connectivity between the TPJ and a part of the brain related to reward and happiness — the ventral striatum — was enhanced in participants who had committed to generosity.

"The connectivity between these two parts of the brain was modulated by the generosity that subjects showed in the experimental task," Kahnt said. "And what’s interesting is that the signal of the striatum itself was directly related to increases in happiness."

By providing neural evidence for a link between generosity and happiness, the study not only advances the field of neuroscience, the authors note, but also has important implications in areas like economics, health and politics.

Kahnt, who contributed to the research while a post-doctoral fellow at the University of Zurich before joining Feinberg, currently investigates the neural and computational principles of reward-guided behavior — in particular, choices related to food.

Funding: The research was supported by grant 0036/AB16 from the Templeton World Charity Foundation, grants PP00P1_128574, PP00P1_150739, 00014_165884 and CRSII3_141965 from the Swiss National Science Foundation and grants PA-2682/1-1 and INST 392/125-1 (Project C07 from SFB/TRR 134) from the German Research Foundation.

Source: Anna Williams – Northwestern Medicine

Image Source: NeuroscienceNews.com image is credited to Kahnt et al./Nature Communications.

Original Research: Full open access research for "A neural link between generosity and happiness" by Soyoung Q. Park, Thorsten Kahnt, Azade Dogan, Sabrina Strang, Ernst Fehr & Philippe N. Tobler in Nature Communications. Published online July 11 2017 doi:10.1038/ncomms15964

Abstract

A neural link between generosity and happiness

Generous behaviour is known to increase happiness, which could thereby motivate generosity. In this study, we use functional magnetic resonance imaging and a public pledge for future generosity to investigate the brain mechanisms that link generous behaviour with increases in happiness. Participants promised to spend money over the next 4 weeks either on others (experimental group) or on themselves (control group). Here, we report that, compared to controls, participants in the experimental group make more generous choices in an independent decision-making task and show stronger increases in self-reported happiness. Generous decisions engage the temporo-parietal junction (TPJ) in the experimental more than in the control group and differentially modulate the connectivity between TPJ and ventral striatum. Importantly, striatal activity during generous decisions is directly related to changes in happiness. These results demonstrate that top–down control of striatal activity plays a fundamental role in linking commitment-induced generosity with happiness.

"A neural link between generosity and happiness" by Soyoung Q. Park, Thorsten Kahnt, Azade Dogan, Sabrina Strang, Ernst Fehr & Philippe N. Tobler in Nature Communications. Published online July 11 2017 doi:10.1038/ncomms15964