Some of that sociality was instinctive, inherited with the primate genes they still share with chimpanzees and apes. Unlike chimpanzees and apes, however, humans had spoken language and a more developed intelligence. To live successfully together they had to develop rules of conduct. And they did. Isolated communities evolved customs, rituals, taboos and magical practices that made life together possible.
Genes are the physical molecular carriers of heredity.
The non-physical language codes are sometimes called memes. These mental and spiritual bonds, encoded now in language, enriched the individual and community lives of all tribal members. These mental memes gave them a sense of identity and when threatened, protected them from other groups of humans. Unfortunately these same memes also led to frequent conflicts with other groups, sometimes violent, always restricting. Then came the next giant step forward on Planet Earth.