Connected in bad times and in good times: Empathy induces stable social closeness

Humans need social closeness to prosper. There is evidence that empathy can induce social closeness. However, it remains unclear how empathy-related social closeness is formed and how stable it is as time passes. We applied an acquisition-extinction paradigm combined with computational modelling and fMRI, to investigate the formation and stability of empathy-related social closeness. Female participants observed painful stimulation of another person with high probability (acquisition) and low probability (extinction), and rated their closeness to that person. The results of two independent studies showed increased social closeness in the acquisition block that resisted extinction in the extinction block. Providing insights into underlying mechanisms, reinforcement learning modelling revealed that the formation of social closeness is based on a learning signal (prediction error) generated from observing another's pain, whereas maintaining social closeness is based on a learning signal generated from observing another's pain relief. The results of a reciprocity control study indicate that this feedback recalibration is specific to learning of empathy-related social closeness. On the neural level, the recalibration of the feedback signal was associated with neural responses in anterior insula and adjacent inferior frontal gyrus and the bilateral superior temporal sulcus/temporo-parietal junction. Together, these findings show that empathy-related social closeness generated in bad times, i.e., empathy with the misfortune of another person, transfers to good times, and thus may form one important basis for stable social relationships. Significance Statement Humans feel close to others if they empathize with them. Here we test whether this feeling of social closeness remains if empathy is no longer elicited. Combining mathematical learning models and functional magnetic-resonance imaging, we find that empathy with others’ pain establishes stable social closeness that is maintained even if the other person is feeling well again. Explaining the mechanism, we show that the stability of empathy-induced social closeness is based on the recalibration of an empathy-related learning signal in the anterior insula/inferior frontal gyrus and the temporo-parietal junction. These findings reveal how empathy maintains social closeness and thus contributes to the formation of stable social relationships.