When Brains Collide

Why are humans so selfish, even at the expense of their young and future wellbeing? Why are humans so technically advanced, yet so primitively violent? While doing research this week I came across the quote below. According to the following theory, it appears that our poor brains have become cross-wired between our ancient ancestors and our REALLY ancient ancestors.

I have long felt that the better we understand our evolutionary roots the better we can deal with our behavior in the modern world. Now that we have the ability to destroy our species at the touch of a button,
it remains to be seen whether our intellectual side can override our
violent side.

Here's what one researcher has to say:

"..... The Phylogenetic Regression-Progression Theory, which is based on 50 years of research by Paul D. MacLean, goes a long way to explain why humans can be devils as well as angels: Our brains are the result of an evolution that incorporates both the instinctive behavior of 200 million years ago with the emotional mammalian addition approximately 100 million years ago and the cognitive capacity that first developed in the neocortex of the great apes approximately 5 million years ago. Depending on our genetic and epigenetic (environmental) makeup, we tend to regress towards our ancient brain or progress to our modern brain. In most cases the direction is under our control."

Source: "Human Paleopsychology: Application to Aggression and Pathological Processes," (Lawrence Erlbaum, 1987) by Professor Emeritus Kent G. Bailey at the Dept. of Psychology, Virginia Commonwealth University, Richmond, Va.