Weekes, Viviana A.

Stepparents commit filicide at higher rates than do genetic parents. According to M. Daly and M. I. Wilson (1994), motivational differences generate differences in the methods by which stepparents and genetic parents kill a child. Using Canadian and British databases, Daly and Wilson (1994) found that stepfathers were more likely than genetic fathers to commit filicide by methods revealing feelings of bitterness and resentment not present to the same degree in genetic fathers. Genetic fathers, in contrast, were more likely than stepfathers to commit filicide by methods that often produce a quick and less painful death. Results replicate and extend previous research conducted by Daly and Wilson (1994). Discussion addresses stepparental psychology, limitations of the current study, and future directions for research and clinical application of this topic.

This dissertation focuses on using one tangible component of filicide, the method or weapon used by a parent to kill a child, as a means by which to understand parental psychology. An evolutionary psychological perspective (e.g., Buss, 2004; Bjorklund & Pellegrini, 2002; Daly & Wilson, 1988; Tooby & Cosmides, 1992) can provide insight into our understanding of filicide. Questions that have not been asked by previous researchers may come to the fore by using an evolutionary perspective as a guide for investigating filicide and its surrounding circumstances and contexts. I present the results of three empirical studies using archival data on filicides recorded in Chicago, Illinois. In Study 1, I present the results of an investigation of parental psychological differences evidenced by the methods of filicide, for filicides recorded between 1965 and 1994. The key results of Study 1 are: (a) while overall (i.e., non-genetic and genetic parents combined), beating was the method of filicide used most often, the percentage of filicides committed by non-genetic parents by beating significantly exceeded the percentage of filicides committed by genetic parents; (b) in contrast, the percentage of filicides committed by non-genetic parents by asphyxiation was significantly less than the percentage of filicides committed by genetic parents. In Studies 2A and 2B, I present the results of an investigation using the 1965-1994 dataset as well as a dataset of filicides-suicides recorded between 1870 and 1930. The key results of these two studies indicate that filicide-suicide may be more likely to occur in certain contexts (e.g., multiple-victim killings) and in certain circumstances (e.g., following paternal filicide). In the final chapter, I discuss the key findings, identify limitations of the current research, and present several future directions for research.