It's more likely for traits to get imprinted in roles, for example priesthoods (shamans), excluded "dirty" social groups (Dalit, burakumin, European Gypsies), a

It's more likely for traits to get imprinted in roles, for example priesthoods (shamans), excluded "dirty" social groups (Dalit, burakumin, European Gypsies), and nobles. But these are all big societies. Perhaps early society, or small enough social groups, can have non-explicit assigned roles and can remember/recognise each other's traits. So who are brave, who are smart/knowledgeable, who are ambitious, who are hardworking, who cheats/lie/snitch to other groups etc.. I think I just described schoolchildren and prison inmates.