Are stepchildren over-represented as victims of lethal parental violence in Sweden?

Evolutionary psychological perspectives on filicide are applicable in modern-day Norway

Current evolutionary psychological (EP) perspectives on filicide perpetration propose that it is an extreme behavioral manifestation of psychological mechanisms that evolved due to their function toward enabling ancestrally adaptive discriminative parental investment. Predictions concerning the characteristics traits of filicide derived from this hypothesis have been empirically supported cross-culturally. Still, it remains a theoretical and empirical question whether EP perspectives on filicide are applicable in societies where the general population is alleviated from ancestrally salient cues to reproductive conflict between individuals and children in their care and the opportunities for lethal caretaker behaviors are highly constricted. Compiling a national sample of filicide cases in modern-day Norway, the present study catered for testing whether EP perspectives on filicide apply in such a society. As predicted, the majority of incidents (79.5%) were associated with perpetrator psychopathology (psychotic episode or filicide-suicide). This further catered for testing the EP hypothesis that filicides associated with perpetrator psychopathology will be characterized by traits that contradict an ancestrally adaptive logic for discriminant parental investment. A full series of predictions derived from this hypothesis was supported as filicides with this association included no step-parental perpetrators and, when compared against filicides that were not associated with perpetrator psychopathology, had older victims and perpetrators and more often multiple victims. The findings confirm the potential applicability of EP perspectives on filicide in progressive and highly developed welfare states, thus lending support to their universal validity.

Physical Abuse of Children by Stepfathers in Colombia

Evolutionary psychologists claim that stepparents perpetrate substantially more child physical abuse than genetic parents, and that they do so because they are less invested in genetically unrelated children. The objective of this study was to examine these claims by investigating whether, and why, fathers in a Colombian sample physically abused their stepchildren more than their genetic children. Fathers (N = 86) and their partners living in Bogotá were interviewed by Klevens et al. Half of the fathers had been reported to authorities for child physical abuse, the other half were matched controls. Secondary analysis was conducted of Klevens et al.'s data. Hypotheses from the evolutionary and ecological accounts of child maltreatment were tested using logistic and ordinal regression. Both the prevalence and the frequency of physical abuse by stepfathers were considerably greater than those of genetic fathers. Several indicators of adversity-including parental youth and experience of abuse, fathers' chronic stress, and mothers' poor communication with the child-were associated with both abuse and stepparenthood. Models including these variables indicated that they accounted for much of the stepfathers' higher rates of abuse. Consistent with the ecological account, much of the stepfathers' greater prevalence and frequency of abuse in this sample is likely to have resulted from confounding variables, rather than from the step relationship per se.