If you want to learn more about this topic, look at the work of Jaak Panksepp. "Archeology of the Mind" is one of the most interesting books I have ever read.

If you want to learn more about this topic, look at the work of Jaak Panksepp. "Archeology of the Mind" is one of the most interesting books I have ever read. His TEDTalk is a quick overview: https://www.youtube.com/watch?v=65e2qScV_K8 https://www.youtube.com/watch?v=65e2qScV_K8