I've been interested in Evolutionary Psychology (EP) for quite some time now. EP focuses on shared human nature; that is, behavioral patterns common to the whole human species. Lately however, I've been also interested in behaviors unique each individual/group of individuals; that is, different personality types, and ways to categorize them. The most famous/reliable way I found was the Myers-Briggs Typology Indicator (MBTI) which divides personalities into 16 different types.