My anthropology theory

This one is fun.
The stone age culture grew and became stable when the humanoid stood up and threw the rock. And the stone age culture remains today, the foundation  of human society. First, dominant handedness and hand eye coordination became the foundation  of tool use.  It is drilled into us from  infancy, stand up and use the dominant hand. Second, the stone age is industrial, piles of rock of different kind carried around for different purpose. Third, there are unlimited ways to combine hide, bone, wood and stone into tool.

Brain theory will back me up and say the brain  can continue growth with hand eye exercise. I sneaked a look. And there was one key change in the cerebellum, the machine that generate muscle neuron  sequences, which occurred in  evolution.

Rock throwers done it.

How did I get my theory? Playing tennis in my living room and reading tennis literature.. The best throw is a throw from an arc in  motion, and that requires a fulcrum, and that requires a sub-dominant counter rotation moment. So we get division of labor in the left/right hands. This is cultural, but biology is the ability to stand.  The mechanics of compound pendulums say this counter pose allows much great throw velocity, especially when combined with running.  The advantages of handedness is so great that it must be the cultural foundation today.