Kinship is a basic organizing principle of all societies. ~ American biologists David Pfennig & Paul Sherman
Sociality begins with family. All kinds of plants and animals know their kin.
Plants typically grow faster in the presence of relations than among strangers. Chemical cues released by roots let relatives recognize one another.
Almost all animals know their relations. Sea squirts lack an identifiable brain but know when they encounter kin.
Western toad tadpoles school with siblings. They also know the smell of their natal home.