Mathematically modelling how humans make decisions has become one of the most interesting challenges that the academic world has tackled in the last fifty years. A focal point of these models is that humans are not purely rational as initially postulated, but are influenced by a wide range of factors, both endogenous (e.g. personality traits, current mood) and exogenous (e.g. society, cultural environment). Using evolutionary game theory and numerical simulations, we investigate how psychopathic personality traits affect both group dynamics and community evolution. Our goal is to provide insight into the circumstances under which the existence of high values of psychopathic traits in some members of the community is advantageous for the population as a whole.
In our work, we investigate how specific aspects of psychopathic traits influence decisions both at the individual and at the group level. Psychopathy is usually described as a constellation of personality traits which include lack of guilt and fear, impulsivity, emotional detachment, impairment in building strong relationships, dishonesty and callousness. As such, psychopathic traits are usually associated with behaviours of negative valence, but this is not always in lines with those personality traits persisting in society. Through numerical simulations, we reproduced the evolution of a community composed of both high and low psychopathic individuals in different environmental conditions. Simulating both benevolent and harsh environments, we observed that high psychopathic community members can help society to overcome the period of crisis, thanks to their fearless attitudes. In this sense, the presence of high psychopathic individuals in a community can be determinant for its survival.
Our research provides a mathematical framework linking psychopathic traits to the dynamics of community resources and survival, broadening the literature that focuses mainly on the impact of psychopathy on individuals. Based on our results, we claim that particular aspects of psychopathy present, to different degrees, in the general population (such as fearless behaviours, callousness and boldness) can be beneficial in harmful situations, providing an advantage for survival.