They did not have agriculture or animal husbandry or writing. Food and shelter were scarce. To survive they had a kind of rough and ready direct democracy. There were tribal elders or chiefs but everyone knew everyone else and everyone was roughly equal. Equally poor in what they could command of energy and material resources.
Humans are a social species.
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.