Modeling complex systems Book

This is the book that inspired me to give up fighting what I saw as mainstream unenlightened biological determinism in psychology, and enrol as a mature age student in psychology while a single parent of four. The language is difficult and challenging and the concepts complex, it took me many attempts to get it, but worth the effort. A classic, an all time favorite. I read it twenty years ago, after having the privelege of attending a workshop with the author, a delightful shamen of a man. His ultimate message is that human beings are biologically programmed for love, and that love and relationship in language is what makes us human.