Mario Vargas Llosa makes a very good point about the conquering of the great Inca and Aztec empires in his essay on their destruction.
He believed that the reason why these empires, which could have possibly been of higher development than Europe itself, were taken down in such hast with only 200 men battling their tribe of 20 million is because once their leader was taken down the people had no one to receive orders from. Without someone guiding their every way these people were invalids. Historian Tom Woods makes a good point when he refers to these tribes as similar to ant colonies- the people (ants) had only one purpose, to serve their master. They weren’t taught to think for themselves or for their well being.
Even up to today we see some thoughtless, almost brainless, people waiting for their orders. Perhaps these people are descendants of the famous Central and South American tribes.