homicidal raids against neighbouring groups are – in human beings and in most other primates – conducted always by males. So encounters between strange females are not necessarily going to turn violent. Moreover, in all apes females are the sex that leaves the group into which they were born when they mate; in monkeys, curiously, it is males that leave. Assuming human beings follow the ape pattern – as they do to this day in most human societies – then women would have had close relations in other groups in the shape of their mothers, fathers and brothers with whom to build relationships.
