This thesis presents the first study of the characteristics traits of caretaker perpetrated child homicide (filicide) in current day Norway, covering the years 1990–2009. Evolutionary psychological (EP) perspectives on filicide are the only theoretical approach that in a comprehensive manner detail the underpinning psychological mechanisms of distinct filicide categories, and predict what traits will be characteristic of perpetrators; victims; and contexts in association with the respective mechanisms. It was therefore of interest, both from a theoretical and a preventive perspective, to test EP predictions concerning the characteristic traits of filicide in the present study.
A complete national sample was compiled of incidents identified through the homicide index held by the National Crime Investigation Service (NCIS) and indictment records of the National Police Computer and Material Services (NPCMS). Court verdicts were used as the data source in incidents where the perpetrator had been convicted. Data was collected from the NCIS’ index for incidents of filicide-suicide.
EP perspectives hold that the parental psychology of the human species has evolved the ability for discriminant investment in children, which may at times result in filicide perpetration. Psychological mechanisms underpinning lethal discriminative parental investment are however seldom triggered in a modern, well-developed welfare state, such as current day Norway (paper I). As expected from EP perspectives, the majority of filicide incidents (79.5%) were instead associated with perpetrator psychopathology (here understood as psychotic episodes or suicidal ideation) (Paper II). Consistent with EP predictions, these filicides had older perpetrators and victims and had more often multiple victims than filicides that were not associated with perpetrator psychopathology. Also in accordance with EP predictions, there were no stepparents among perpetrators suffering psychopathology. The present study thus adds current day Norway to the growing list of societies in which EP predictions concerning the characteristic traits of filicide have been empirically confirmed, which lends support to EP perspectives on the underpinning psychological mechanisms of filicide.
Current EP perspectives, however, have a shortcoming in that they do not explicitly account for the apparent variability individuals have in their risk for filicide perpetration. Drawing on evolutionary developmental psychological (EDP) perspectives on individual differences, I hypothesised a possible developmental origin to such variability in childhood experiences with parental investment, and predicted that filicide perpetrators will often have had experiences with extremely low levels of investment. The empirical literature supported the hypothesis, as it reports that the majority of filicide perpetrators (63% to 84%) have traumatic childhood experiences of physical, sexual and emotional abuse; neglect; and abandonment by their own parents (Paper III).