Cinderella effect in psychology

The Cinderella effect in psychology refers to the phenomenon in which stepparents are more likely to engage in abuse towards their stepchildren than biological parents. 

This concept was coined by Martin Daly and Margo Wilson in 1994, drawing inspiration from the fairy tale of Cinderella, in which a stepmother mistreats her stepdaughter. According to the theory, stepparents are more likely to mistreat their stepchildren because they are not biologically related to them and do not have the same emotional connection to them as biological parents. This lack of connection can lead to less investment in the child's well-being and increased feelings of jealousy towards the child's biological parent.

Critics of the Cinderella effect theory argue that the evidence is not strong enough to support such a broad conclusion, pointing out that there are many factors that can contribute to child abuse, including poverty, stress, and mental illness. Additionally, critics argue that the theory ignores the fact that many stepparents have positive relationships with their stepchildren and that many biological parents are also capable of abuse. See a critique by David Buller (2005).

Daly and Wilson (2008) offer a careful explanation of the research supporting the Cinderella Effect and a detailed response to Buller and other critics. Following is a quote from their 2008 chapter (p. 383).

Skepticism is useful faculty for any scientist, and one that the social sciences afford their practitioners abundant opportunities to exercise. However, the work of evolutionary psychologists has elicited more than its share of skepticism, for reasons that seem to have little to do with the quality of either the theorizing that motivated the researchers' hypotheses or their evidence. An example is provided by critical reactions to our own research on the "Cinderella effect." The phenomenon at issue is parental discrimination against stepchildren, relative to how parents treat their birth children. It is manifest both in reduced levels of investment in stepchildren and in elevated rates of mistreatment, up to the extreme of lethal abuse. Given the ubiquity of abused stepchildren in folklore and the pervasive negative stereotyping of stepparents (e.g., Fine, 1986), any child-abuse researcher might have wondered whether steprelationship is genuine risk factor, but in fact, those whose imaginations were uninformed by Darwinism never thought to ask. We conducted the first comparison of abuse rates in stepfamilies versus intact birth families, and the difference turned out to be large (Wilson, Daly, Weghorst, 1980).

The evidence of high rates of abuse of nonbiological children compared to abuse of biological children is alarming and worth considering proximal and distal causes for the data. Certainly, one should not ignore contributing factors and what may be done to insure safer environments for children. Although it is reasonable to be sceptical of the evidence, it should not be ignored. Instead, more data should be collected in accordance with rigorous guidelines.

Readers should also be careful to separate criticism of the data from criticism of the theories attempting to explain the data. Theory building is an ongoing process informed by data. Cognitive biases can interfere with a fair analysis of any theory.

References

Buller, D. J. (2005). Adapting minds: Evolutionary psychology and the persistent quest for human nature. MIT Press.

Daly, M., & Wilson, M. (1994). Evolutionary social psychology and family homicide. Science, 267(5197), 249-252.

Daly, M., & Wilson, M. (2008). Is the "Cinderella effect" controversial?: A case study of evolution-minded research and critiques thereof. In C. Crawford & D. Krebs (Eds.), Foundations of evolutionary psychology (pp. 383–400). Taylor & Francis Group/Lawrence Erlbaum Associates.

Wilson, M., & Daly, M. (2001). Risk of maltreatment of children living with stepparents. In D. P. Farrington & J. W. Coid (Eds.), Early prevention of adult antisocial behaviour (pp. 178-197). Cambridge University Press.