News: IPMC Publication/Nature Neuroscience/B. Silva Team
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Why are some people more altruistic than others? New research suggests that part of the answer may lie directly in the brain, in the mechanisms that govern social learning. The study, coordinated by prof. Diego Scheggia from the Department of Pharmacological and Biomolecular Sciences «Rodolfo Paoletti» at the University of Milan, in collaboration with Carlo Castoldi and Bianca Silva at IPMC, has been published in Nature Neuroscience (https://www.nature.com/articles/s41593-026-02292-2#Sec33).
The research shows that sharing and cooperative behaviors can also be learned by observing others. In the experimental models analyzed, individuals quickly learn the relationship between actions and their consequences without needing direct experience — not only in contexts of danger, but also in the case of positive experiences. They therefore demonstrate a flexible and adaptive capacity for social learning. Notably, the observing animals do not merely imitate: they are able to understand the consequences of actions and adapt their behavior even when the context changes. This indicates that observation generates a more complex form of learning than simple copying, one based on associations between an action and its benefit for others.
A central element of the research concerns the role of the hippocampus, and in particular its dorsal region (dCA1), which proves crucial for this type of social learning. When activity in this area is disrupted during the observation phase, the ability to learn social behaviors is reduced, while basic memory and motor skills remain intact.
Even more significant is the finding that not all individuals respond in the same way: starting from the same experience, meaningful differences emerge, with some individuals more oriented towards prosocial choices and others towards more selfish ones. These differences take shape during the observation phase itself, through distinct patterns of neural activation in the hippocampus.
The results also indicate that this process is plastic: by intervening in dCA1 activity, it is possible to modify future choices, making individuals more inclined towards sharing or, conversely, more oriented towards selfish behavior.
