Easily clip, save and share what you find with family and friends. Easily download and save what you find. For the analytical report of the cognitive development of children of preschool age with the same name in semiconductors, see floating body effect. In evolutionary psychology, the Cinderella effect is the phenomenon of higher incidence of different forms of child-abuse and mistreatment by stepparents than by biological parents.
It takes its name from the fairy tale character Cinderella. In the early 1970s, a theory arose on the connection between stepparents and child maltreatment. For over 30 years, data has been collected regarding the validity of the Cinderella effect, with a wealth of evidence indicating a direct relationship between step-relationships and abuse. This evidence of child abuse and homicide comes from a variety of sources including official reports of child abuse, clinical data, victim reports, and official homicide data. Powerful evidence in support of the Cinderella effect comes from the finding that when abusive parents have both step and genetic children, they generally spare their genetic children. In such families, stepchildren were exclusively targeted 9 out of 10 times in one study and in 19 of 22 in another. Daly and Wilson point out that infanticide is an extreme form of biasing parental investment that is widely practiced in the animal world.
For example, when an immigrant male lion enters a pride, it is not uncommon for him to kill the cubs fathered by other males. Unlike the lion, however, humans in a stepparenting situation face a more complicated tradeoff since they cannot completely disown their partner’s offspring from a previous relationship, as they would risk losing sexual access to their partner and any chance of producing potential offspring. Thus, according to Daly and Wilson, stepparental investment can be viewed as mating effort to ensure the possibility of future reproduction with the parent of their stepchild. Daly and Wilson report that this parental love can explain why genetic offspring are more immune to lashing out by parents. They assert that, “Child-specific parental love is the emotional mechanism that permits people to tolerate—even to rejoice in—those long years of expensive, unreciprocated parental investment”. Daly and Wilson’s reports on the overrepresentation of stepparents in child homicide and abuse statistics support the evolutionary principle of maximizing one’s inclusive fitness, formalized under Hamilton’s Rule, which helps to explain why humans will preferentially invest in close kin. This was accomplished by administering a randomized telephone survey.
Records of child abuse from children’s aid organizations as well as police reports on runaways and juvenile offenders were then used to determine whether children from stepparental living situations were overrepresented as abuse victims when compared to the demographic data gathered from the telephone survey data. The results indicate that the only living situation that has a significant correlation to increased child abuse is one natural parent and one stepparent in the same household. Evolutionary psychologists have also suggested that one of the causes of stepchild abuse may be the lack of a parental attachment bond that the mother would normally form with her own child. An attachment bond will, in general, be more secure if formed before the age of two, and adoption can often disrupt the development of this bond. It is sometimes argued that this evolutionary psychological account does not explain why the majority of stepparents do not abuse their partners’ children, or why a significant minority of genetic parents do abuse their own offspring. Strong support for the Cinderella effect as described by Daly and Wilson comes from a study of unintentional childhood fatal injuries in Australia. Daly and Wilson to extend the Cinderella effect from cases of abuse to incidences of unintentional fatalities.
Based on data gathered from the Australia National Coroners’ Information System, stepchildren under five years of age are two to fifteen times more likely to experience an unintentional fatal injury, especially drowning, than genetic children. Furthermore, a study of parental investment behaviors among American men living in Albuquerque, New Mexico, reveals a trend of increasing financial expenditures on genetic offspring in comparison to step-offspring, which also suggests that parents are less inclined to preserve the well-being of stepchildren. Though the general trend of the data from this study supports the Cinderella effect, Anderson and colleagues note that the observed differences between investment in children and stepchildren might be slightly reduced by a few confounding factors. Additionally, a study of Hadza foragers in Tanzania by Marlowe also finds evidence of decreased care provided by men to stepchildren when compared with genetic children.
In further support of the Cinderella effect as elaborated by Daly and Wilson, a study conducted in a rural village in Trinidad demonstrates that in households containing both genetic children and stepchildren, fathers devote approximately twice as much time to interaction with genetic offspring in comparison to stepchildren. Buller also argues that Daly and Wilson’s findings are inherently biased since they use data from official documents, and the officials collecting that data are trained to take special notice of stepparents versus biological parents. The findings of Daly and Wilson have been called into question by one study of child homicides in Sweden between 1975 and 1995, which found that children living in households with a non-genetic parent were not at an increased risk of homicide when compared to children living with both genetic parents. Daly and Wilson attribute the contrasting findings of the Swedish study to an analytical oversight. Temrin and colleagues neglect to consider the fact that the proportion of children in living situations with a stepparent is not constant for all child age groups, but rather increases with age. After correcting for age differences, the Swedish data set produces results in accordance with the previous findings of Daly and Wilson.
It has been noted by multiple researchers that child abuse is an intricate issue and is affected by other factors. Burgess and Drais propose that child maltreatment is too complex to be explained fully by genetic relatedness alone and cite other reasons for child maltreatment, such as social factors, ecological factors and child traits such as disability and age. However, they also note that these traits are simply indicative, and do not inevitably lead to child maltreatment. In 1984, Giles-Sims and David Finkelhor categorized and evaluated five possible hypotheses that could explain the Cinderella effect: “social-evolutionary theory”, “normative theory”, “stress theory”, “selection factors”, and “resource theory”. Discussing the implications of this line of research, Australian psychologist Greg Tooley, author of a 2006 study confirming the existence of the effect, confessed that “it is certainly difficult to talk about because it is such a hot issue”.