The “Cinderella Effect”: Violence and Abuse Towards Stepchildren

This entry was written by Martha Gledhill-Tuite as part of a project done in BIAN 2133 ‘Human Reproductive Strategies’ at The Australian National University in 2019 Semester 2.


Cinderella was a fairy tale character who was severely mistreated by her stepmother, while her stepsisters were spoiled. In the modern day, studies exhibit that stepchildren receive less investment than genetic children, including money, time and emotion. This has been labelled the “Cinderella Effect” (CE; Daly & Wilson, 2007, 2014; Gelles & Harrop, 1991; Tooley et al., 2006; Wilson, Daly & Weghorst, 1980). In the rarest and most extreme cases, the CE manifests as violence towards the stepparent’s stepchild. Abuse and homicide have been widely studied in support and disputation of the CE. This entry will outline the literature surrounding stepparental abuse and homicide, and unintentional fatalities.

Main Text

Evolutionary Explanation of the CE

The CE can be explained by evolutionary theory. Parenting is energetically and resourcefully expensive, but it is beneficial in order to aid the continuation of the parents’ genetic material. To facilitate this, human parents have evolved to experience a parental feeling towards their own genetic children. Because parenting is so expensive, stepparenting only occurs as a type of mating effort. Becoming a stepparent allows access to mates with offspring, but the parental feeling is unlikely to be stimulated in stepparents, as the stepchild’s survival is not evolutionarily beneficial to them. For this reason, stepparents are likely to invest less in stepchildren than in biological children. Supporting this concept, research demonstrates that only 25% of stepmothers and 53% of stepfathers report experiencing parental feelings towards their stepchildren. (Daly & Wilson, 2007, 2014; Gelles & Harrop, 1991; Tooley et al., 2006; Wilson, Daly & Weghorst, 1980)

Household Composition and Child Abuse

An early study on the CE compared household composition of child abuse cases. They discovered that abuse is more common in households containing a stepparent than those containing both genetic parents. The major limitation of this study is that it does not identify the perpetrator, as it could be any individual in the household. Since then, however, further research and analyses have provided more detailed information. (Wilson, Daly & Weghorst, 1980)

Fatal Batterings of Stepchildren

The statistics amassed by Daly and Wilson (2007, 2014) illuminate the risk of violence towards stepchildren. In Canada, fatal batterings of children are 120 times more likely to be committed by stepparents than by biological parents. Similarly, in England and Wales, young children are over 100 times more likely to experience fatal battering by a stepparent than genetic parent. Children with stepparents in Australia are at 300 times the risk of children with both biological parents, although the sample size for this analysis was small. These trends are similar across numerous Western countries. Despite the fact that most of these comparisons focus on stepfathers, stepmothers are also more likely to be abusive to stepchildren than their biological counterparts. There are simply less statistics surrounding stepmothers because fewer small children live with stepmothers than with stepfathers.

Alternative Explanations for the CE

It has been proposed that other, non-evolutionary factors could cause of this pattern of stepparental violence. Poverty is a known correlate of child abuse, so this could be the reason behind stepparental abuse, if families with stepparents have lower incomes. This does not explain differences between biological parents and stepparents, however, as their incomes are very similar. Furthermore, there is no correlation between income and the presence of stepparents in the United States. Alternatively, there might be some element of personality that is common in people who become stepparents, predisposing them to violence. This theory is contradicted by the tendency for stepparents to abuse only their stepchildren, and not harm their biological children. These explanations are unable to fully account for the features of stepparental abuse towards stepchildren. (Daly & Wilson, 2007, 2014)

Contradictory Results

One study by Gelles and Harrop (1991) suggested that families with stepparents are no more likely to contain violence than biological families. They conducted a study in which they interviewed American households at random and asked whether the interviewee had had any violent confrontations with children or stepchildren within the last year. After controlling for the factors of income, age and gender of children, the results were contradictory to those of other studies. They indicated that stepparents are less likely to behave violently or abusively towards stepchildren than biological parents. The authors suggest that these results disprove the existence of the CE, but Daly and Wilson (2007, 2014) argue that the study was flawed. People are unlikely to admit to familial violence in an interview, especially stepparents who are cognisant of the negative image associated with their role. Regardless of the shortcomings of the study design, the results of one study cannot disprove an entire theory. The claims from Gelles and Harrop (1991) that their study invalidates the CE are unfounded.

Unintentional Fatalities

Also relevant is a study undertaken by Tooley et al. (2006) on Australian coroner reports, comparing child death rates from unintentional fatalities. They theorised that children from stepfamilies would be more highly represented, because stepparents are less likely to invest in supervision of their stepchildren. As not each case included information about household composition, they completed two analyses: one that disregarded those with unknown familial structure, and one that included them as intact biological families, in order to eliminate potential reporting bias. They discovered that, in both analyses, stepchildren were overrepresented in unintentional fatalities, especially drowning. They proposed that the reason behind this was decreased supervision of stepchildren by stepparents. This represents decreased investment.


Studies on abuse and homicide of children show a clear trend: stepparents are more likely to victimise stepchildren than biological parents are (Daly & Wilson, 2007, 2014). Unintentional fatalities are also more common in households with a stepparent, compared to those with two biological parents (Tooley et al., 2006). One study seems to contradict all other results in providing no evidence for the CE (Gelles & Harrop, 1991), however this study is heavily flawed. These results exemplify the extreme embodiment of the CE, and provide support for the theory that parents invest less in stepchildren than in biological children.

Literature Cited

Daly, M., & Wilson, M. (2008). Is the ‘Cinderella Effect’ controversial? In C. Crawford & D. Krebs (Eds.), Foundations of evolutionary psychology (pp. 383-400). New York, NY: Taylor & Francis Group/Lawrence Erlbaum Associates.
Daly, M., & Wilson, M. (2014). The “Cinderella effect”: Elevated mistreatment of stepchildren in comparison to those living with genetic parents. Department of Psychology, Neuroscience & Behavior, McMaster University, hamilton, Ontario, Canada.
Gelles, R. J., & Harrop, J. W. (1991). The risk of abusive violence among children with nongenetic caretakers. Family Relations, 40, 78-83.
Tooley, G. A., Karakis, M., Stokes, M., & Ozanne-Smith, J. (2006). Generalising the cinderella effect to unintentional childhood fatalities. Evolution and Human Behavior, 27(3), 224-230.
Wilson, M. I., Daly, M., & Weghorst, S. J. (1980). Household composition and the risk of child abuse and neglect. Journal of Biosocial Science, 12(3), 333-340.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License