Final answer:
The basic unit of primate social groups is female kinship and solidarity, centered around related females and their offspring.
Step-by-step explanation:
The basic unit of all primate social groups is the female kinship and solidarity. While primate societies are complex and both sexes play essential roles, the core consists of closely bonded mothers and their young. Related females make up the heart of these groups, with males often being temporary members who move between groups. Female primates build this unit through reproduction and nurturing, and they are central to the social life within these communities, often forming strong bonds that hold the group together.