Evolutionary psychology offers several explanations for human violence in various contexts, such as sexual jealousy in humans, child abuse, and homicide. Goetz (2010) argues that humans are similar to most mammal species and use violence in specific situations. He writes that "Buss and Shackelford (1997a) proposed seven adaptive problems our ancestors recurrently faced that might have been solved by aggression: co-opting the resources of others, defending against attack, inflicting costs on same-sex rivals, negotiating status and hierarchies, deterring rivals from future aggression, deterring mate from infidelity, and reducing resources expended on genetically unrelated children."