A study by the Institute for Research and Innovation in Health (i3S) at the University of Porto suggests the existence of a link between psychopathic traits and bacteria in the gut and mouth. “We cannot say that bacteria cause psychopathic traits, but we observed a relationship between certain oral and gut bacterial profiles and specific behavioural characteristics”, notes Benedita Sampaio-Maia, coordinator of the study and a researcher at i3S. Among main findings, the team “identified associations between psychopathic traits and some specific gut bacteria”. The institute states that “psychopathy involves a set of characteristics such as impulsivity, manipulation, lack of empathy and antisocial behaviour”. In this study, researchers recruited 200 Portuguese people and assessed “psychopathic traits, empathy and anxiety using psychological assessment scales”.