Altruistic or Secretly Selfish? Your Brain Could Reveal Your True Motivation

Interactions between brain regions reveal motives behind actions, University of Zurich study finds


Could science show who is truly generous or just out for themselves? Images of the human brain could reveal the answer.

Scientists at the University of Zurich in Switzerland have discovered that interactions between the brain's regions can show private motivations behind people's actions, including whether someone is acting kindly from a place of true empathy or a place of expecting something in return.

“The whole notion of a motive is that it’s a mental concept you cannot observe directly," lead author, Ernst Fehr, a neuroscientist at the University of Zurich's Department of Economics, said in an interview with Scientific American. "And we were able to show that we could make this visible.”

Researchers divided 34 female subjects into two groups. The empathy-induction group was given a partner who received pain shocks, while the participants also received shocks themselves. The second reciprocity-induction group had partners who gave up money to help the subjects receive less shocks. Both groups also had a second, neutral partner.

In the second part of the study, the subjects had to divide money between themselves and their partners while their brains were scanned using a functional magnetic resonance imaging (fMRI) scanner. The participants split money with the partners receiving shocks before doing the same with the neutral partner. This way, the study subjects' natural giving tendencies could also be determined.Those who consistently kept money for themselves were labeled "selfish," while others were "prosocial," or altruistic.

The scans found that empathy-based and reciprocity-based generosity produced different interactions between regions of the brain that activate during altruistic behavior.

"The impact of the motives on the interplay between different brain regions was so fundamentally different that it could be used to classify the motive of a person with high accuracy," Grit Hein, psychologist from the Department of Economics, said in a press release.

After scanning the brains, the researchers used a computer algorithm to guess whether an action was based on empathy or reciprocity and got a result of 80 percent accuracy.

The researchers also found that the brains of selfish people and prosocial people reacted differently during the divvying up of money. Selfish people also seemed to give more money after feeling empathy, whereas altruistic people gave more when feeling they needed to reciprocate.

Cendri Hutcherson, a psychologist at the University of Toronto who was not involved in the study, told Scientific American in an interview that this study could bring researchers one step closer to finding out if generosity can be a learned behavior.

“One huge question, given the range of benefits associated with prosocial behavior, is how people who are already generous or selfish in that baseline condition get to that point,” Hutcherson said. “Is this about genetic differences? Is this about training or education?”

This study was published March 3 in the journal Science.

Funding sources and disclosures were unavailable at time of publication.