Evolutionary personality psychology
Evolution has not only shaped our bodies but also our minds; affecting how we behave and think. Most of our actions are just mechanisms that reflect psychological adaptations that have historically helped with reproduction and survival. The cost-benefit analysis suggests that we intrinsically help those we expect will help us later. This concept was clear to me when I chose to help my best friend with the little cash I had saved. A girl I was with back then had asked me for money but I hesitated to give her. However, my best friend and I have come a long way and he has helped me out more than I count. I was easy to give where I was sure to receive and not elsewhere.
Evolutionary personality psychology focuses on why people behave the way they do, unlike evolutionary psychology that simply observes how people behave. From the evolutionary perspective, personality is an evolved psychological mechanism that comes about as a response to social adaptation. This psychology attributes irrational and compulsive behavior such as murder-suicide to the social environment which the perpetrator interacted with. Sexual selection and parental investment play a very important role in the shaping of the psychopath or sociopath or any other psychology that may be moved to commit homicide and suicide.
I affirm with the evolutionary personality psychology attribution of jealousy and how men and women experience it in different ways. My personal experience with the relationships I have had suggests that as a man I would rather my girlfriend was soliciting another man for money rather than sex. I also think that my girlfriend would be more jealous if she found that I had spent a huge chunk of the money I had saved for her on another woman than if she found me sleeping with another woman. Evolutionary psychology is key to the conceptualization of human personality.