Cinderella effect

In evolutionary psychology, the Cinderella effect describes the phenomenon of a higher incidence of child abuse and mistreatment by stepparents than biological parents. It takes its name from the fairy tale character Cinderella, a girl who is mistreated by her stepmother and stepsisters. Evolutionary psychologists describe this effect as being a byproduct of a bias towards biological family and a conflict between reproductive partners investing in young children that are unrelated to one partner.^[1]