We have all heard the old "nature vs. nurture" debate used to discuss the root of a variety of behaviors and personality traits. I'm sure somewhere along the line, most people have drawn their own conclusions. The majority of people I know attribute a combination of DNA and environmental factors as the explanation for our behavior.
If you are familiar with cases such as the taming of the Siberian Silver Fox, you may or may not have questioned the significance of environmental factors playing a role in personality development.
For me, cases such as the taming of the silver fox highlight the potency of anatomical chemistry and lead me to believe that our DNA has a much larger influence over who we are and how we choose to express ourselves than we may like to accept. After all, if we are all just bags of DNA walking around playing out our personal programmed lines of genetic code, that realization could open the door to an unpleasant sci-fi like future where our DNA strands are valued above all.
Even the most superficial examination of historical records will show how nasty human beings can be and how we can target just about anything to torment and destroy one another.
Random Thought: If diversity is so important for the continuation of a species over the ages, why does our DNA seem to program us to fear and possibly eliminate anything unlike ourselves?