An individual who did not meet society's expectations could be excluded from the group. This meant that the individual lost the group's protection against other groups, lost the group ability to hunt cooperatively, lost the group ability to make secure shelter, and perhaps most of all, lost the group history and tradition. The latter may well have been most important, inasmuch as in a pre-literate society, the cultural heritage was controlled by only a few individuals who were charged with remembering where the animals were during different seasons, where water could be found, and where danger lurked. Even today in the Australian outback, an occasional aborigine may ignore this lore and travel when a waterhole is dry. They are so far apart and difficult to find that there is no saving recourse.
Death awaits the impetuous now as it did in the remote past.
As tribes became larger, societal pressures were not enough to keep the imprudent or impulsive individuals in check. Organized religion was the next most likely evolving cultural force used to effect this. Religion of sorts had been around, in that the shamans frequently cloaked their knowledge under a guise of supernatural power. For them, given the lack of scientific insight available, it may have seemed as such. But the message of both the tribe, and of organized religion was pure cause and effect.