Forces of Evolution play a huge part in deciding who we are, how we behave, what our values are, how our cultures evolve, etc. To understand yourself, or your society, you will have to understand how Evolution works and the effects it has on all of us.
Here are some post, arranged in order, that will help you get that clarity.
This post gives you are primer on how Evolution works. Some of the concepts of evolution are counter-intuitive. It is best to take a quick look into this article.
This post identifies three different of selection forces (“Me” Selection, Sexual Selection and Group Selection) that make us who we are. Interplay of these selection forces produces most of our characteristics, the same way three primary colors in the color wheel mix together to form all the hues that the eyes can see.