Alongside classical theories on “human nature”, such as those by Rousseau and Hume, which view society as the corruptor of our intrinsic natural goodness, on the one hand, and see the human being as characterised by an irreducible tendency towards selfishness and oppression (“homo homini lupus”), on the other, recent decades have seen a gradual consolidation of a different view of human nature that sees us, above all, as a social species capable of great drives of cooperation. We are social mammals, as are chimpanzees, the closest species to us in the evolutionary scale. With chimpanzees we share positive aspects of sociality, such as cooperation and altruism, and aspects we can consider negative, such as group aggression. It is our peculiar sociality that has enabled our greater rate of survival and reproduction. It is thus to sociality that we must turn with great attention when embarking on prevention programmes. Although it has long been known that one of the factors which can lead a teenager to deviant behaviour is mixing with peers having the same problems of deviance, paradoxically, many strategies of recovery are instead based on interventions which tend to group together young people with behavioural problems. One reason for the unexpected negative effects of programmes based on group actions may be linked to the fact that, thanks to our great sociality, we easily assimilate the characteristics of the group we belong to and we use the group’s methods. It is this being in a group, to achieve greater status and greater consideration among one’s peers of reference, that enables us to be more successful in reproduction. Moreover, we are hierarchical animals and belonging to a group is not so much a matter of choice but a need linked to actual survival. Considering our capacity for subjection may shed new light on the dynamics of belonging – especially within a certain age-group – to teenage gangs or even sects. At the same time, from an evolutionary standpoint, it is small wonder that criminological data point to the fact that a different way of experiencing sociality and improving fitness, for example, through marriage, work or child-rearing, leads to the gradual abandonment of delinquent behaviour.