Americans are a “self-selected” group. By that I mean that the people that came here (Irish, English, Scots-Irish, German….) were a little bit different then their countrymen. To l eave home and cross an ocean to a continent unexplored and full of dangers requires a certain mindset (or level of mental illness).

Let me give a specific example. It has been proven that a higher percentage of the American population suffers from hyperactivity then other countries. Psychologists believe that originally the genetic pre-disposition for hyperactivity was fairly evenly spread throughout the human race. But think about it – you have two bothers living somewhere in Europe. One is hyperactive and one is not - which is more likely to immigrate to the New World. The hyperactive one would more likely move to America. Here he is more likely to meet a woman who is hyperactive and to pass down that trait to his children.

Who would be more likely to leave England, Ireland or Germany a mild mellow guy he gets a long with people, or the kind of guy who could get into a fight a church? The wild and wooly frontier would appeal more to him then to the more socialized fellow. Over time both “nature” and “nurture” brought out the more aggressive nature in people.

This is not to say anything bad. Aggression is a survival positive characteristic in many situations (if not carried to extreme). Also, I realize that many people who came here to America did not do so willingly (Africans brought as slaves, the Irish whose only other choice was starve).