Evolution of Desire

As a child i was very interested in how why people behave the way they do maybe that little autistic spectrum like i would do people work really i don't get it and so i took that into research just like well i'm going to figure out from an animal focused research perspective and go from there. Even though i probably am less confounded by social situations as I was as a child i'm a lot more socially socialized as i am at all but still have that general interest of what causes people to behave whether they do where are these beliefs and feelings and compulsions that we have where do they come from? If you give me a little bit i'll eventually come back and have a book