The Cinderella effect is a phenomenon in which stepparents abuse and kill their spouse's biological children at higher rates than they do of their own children (Daly & Wilson, 2007; Sariola & Uutela, 1992; Weekes-Shackelford & Shackelford, 2004).1 Empirical studies have captured evidence of the Cinderella effect across different places (Alexandre, Nadanovsky, Moraes, & Reichenheim, 2010; Sariola & Uutela, 1992) and over time (Daly & Wilson, 1985; Nobes, Panagiotaki, & Russell Jonsson, 2019;...