Its a chichen or egg phenomenon, which came first lower testosterone or elevated humanity? Once early man developed the skill and weaponry needed to become the greatest predator, then it no longer was necessary for males to be as large, strong and fierce to use brute force to hunt( as chimpanzees have been witnessed to do) , and overtime with an abundance of food provided for by an advance in tools, survival no longer depended upon the males with high testosterone chasing down and bashing animals with primitive rock axes. Instead it became much more important for all the males and females to live more efficiently and cooperatively, so levels dropped to facilitate a more domestic way of life.
We now live in a completely domesticated age, testosterone levels have dropped even lower, and it is no longer necessary for survival for men to be much stronger and hormonally driven.
