Hunting and gathering societies were, and to some extent still are, very small, isolated, and, therefore, intimate. They are more like big families than small countries. but they were the largest social unit that mattered in the day to day life of the typical person and therefore were, by definition, societies. The people in these societies ranged over sizeable gathering and hunting territories, so they tended to have no permanent settlements and few material possessions. Subsistence occupied a relatively small portion of each day and there was little other work that needed doing so these societies are sometimes referred to as "the first leisure societies."
These features facilitated other characteristics which have been noted and which I believe were once typical: social equality, deep caring for one another, love of children, gentle and peaceful attitudes and behaviors, good intergender relations, and a culture that generated intensely and widely cultivated spiritual experiences. Human beings preserved this way of life for over two hundred thousand years, and surrendering it may have been our greatest mistake.
Was there a down side? From a modern point of view, gathering and hunting based life seems narrow, deprived, unhealthy, and uncreative. Perhaps life was shorter and less healthy. But it must be remembered that modern societies had an impact on these simple societies long before they gathered statistics about them. It could be argued that the worst features of these societies were the result of the intended and unintended consequences of advanced horticultural, pastoral, agrarian, or industrial societies. These intrusions have forced gatherers and hunters to fight, die, change, or flee-- all about equally unsuccessful as solutions.
I have spent a lot of time wondering why and how some gatherers and hunters became horticulturalists and then "advanced" horticulturalists. People who were not egocentric had to become egocentric; people who never felt superior to others had to come to believe they were superior to others. People who cared nothing for property had to become willing to fight and die for it and to care more about it than they did their fellow human beings. I do not believe a god cast people out of eden, so why did they leave?
Perhaps what we know about the related psychologies of power and social distance can be helpful. We know that people do not have to be corrupt to attain power, but power corrupts those who attain it. We know that people on the bottom side of the power equation are more sensitive to its corruption and injustice. We know that if we think people threaten us or don't appreciate what we are doing for them or accuse us of corruption or injustice, we tend to dislike them and try to separate ourselves from them physically or symbolically. We know that people in leadership roles acquire a sort of paranoia about the alleged ungratefulness of those being led. On the other hand, leadership is probably a natural and necessary function in any group. If a person is successful in fulfilling this function she or he is likely to asked to lead again and again until she or he becomes a "leader" and begins to acquire the power and corruption that goes with permanent leadership. "Primitive" societies have all kinds of devices to prevent this from happening. But is easy to imagine extreme circumstances in which those devices fail.
Among the hundreds of thousands of hunting and gathering societies that must have existed in 11,000 b.c.e., there must have been some that were more threatened than others by climate change, loss of game, or other dangers. Forty people, half of them children, cannot afford many mistakes, many fruitless food excursions, etc. Leadership may come to seem so crucial that people are willing to suffer a little bit of pride, egocentrism, or even ill humor in a person who can make a difference in chances for survival. If so , they may have taken the first step out of the garden (pardon me, I meant to say forest), the first step that became a journey of ten million miles.