Kids are the root cause

Evolutionary mechanics never cease to amaze me. Darwinian theories of survival of the fittest have for long being embedded as long time explanations of why species gradually change and how some go extinct. Natural selection also explains how what is 'heritable' is carried along and the unnecessary appendages pruned along the way.

Everyone know about how some African apes got off trees and attempted to look over the grass. They were not strong, fast or gifted with any other behavioral trait, apart from perhaps the oldest of them.... survival of the fittest. To ensure that they could spot likely predators, these apes started standing tall to look over the tall grass. As they spent more and more time doing this, they began to notice that this act left their fore limbs to do tasks. So they began using tools and truly utilizing the opposable thumb.

These puny apes, thus began a evolutionary mechanism that gathered pace at an exponential pace. Malcolm Gladwel, talks about the 10,000 hour rule. Our ancestors were no different. As they began spending more and more time standing, their spines began getting shaped to facilitate this process. Their usage of tools and other techniques instigated their brains to think faster... think more and think in different factions along varied lines. As a result, their brains literally began to grow. Their brains grew in size as the evolution came along. However large brains created a hindrance as it would be fatal for both the mother and the child during childbirth.

Evolution's response to this was ensuring that 'human'(though I don't know what lead us to be called that) infants were born early on in their development. Most of the brain growth happens outside the mothers body. However this lead to the additional complication of the infants being completely helpless in their years. Apart from a few reflexes they could barely manage any other limb coordination.

This demanded that humans organize themselves into a society to ensure that their young ones are nurtured. Thus the primary purpose of a societal set up is to ensure that the young ones are cared for.