Decisions in social contexts might lead to choices favoring self-or others-interest, depending on the relationships between individuals. Prosocial and helping behaviors are evolutionary conserved across mammals. However, the neurobiological bases of choices that bene t others at a personal cost are not understood. Here, we revealed the role of the basolateral amygdala (BLA) in altruistic and sel sh choices.We developed a two-choice social decision-making task in which mice could decide to share or not a positive reinforcement with their conspeci cs. Preference for altruistic choices was more evident in males and if the conspeci c was familiar. In particular, altruistic choices were associated with social dominance and affective state matching between individuals. Chemogenetic BLA neuronal silencing induced lower ranking hierarchy and less preference for altruistic choices. This provides a neurobiological comparative model of altruistic and sel sh choices versus dominance hierarchy and emotional contagion, with relevance to pathologies associated with dysfunctions in social decision-making.

Genetic 16p11.2 and 22q11.2 deletions and duplications in humans may alter behavioral developmental trajectories increasing the risk of autism and schizophrenia spectrum disorders, and of attention‐deficit/hyperactivity disorder. In this review, we will concentrate on 16p11.2 and 22q11.2 deletions' effects on social functioning, beyond diagnostic categorization. We highlight diagnostic and social sub‐constructs discrepancies. Notably, we contrast evidence from human studies with social profiling performed in several mouse models mimicking 16p11.2 and 22q11.2 deletion syndromes. Given the complexity of social behavior, there is a need to assess distinct social processes. This will be important to better understand the biology underlying such genetic‐dependent dysfunctions, as well as to give perspective on how therapeutic strategies can be improved. Bridges and divergent points between human and mouse studies are highlighted. Overall, we give challenges and future perspectives to sort the genetics of social heterogeneity.