Namesaking can be viewed as a mechanism to increase perceived parent-child similarity and, consequently, parental investment. Male and, to a lesser extent, firstborn children are more frequently namesakes than female and later-born children, respectively. However, a direct link between namesaking and parental investment has not been examined. In the present study, 632 participants from Central Europe indicated their first name, sex, birth order, number of siblings, sexual orientation, socioeconomic status, paternal and maternal first names, as well as relationship quality with, (...) and time and financial investment they received from, both parents during childhood. Mixed-effects models revealed associations between namesaking and parental investment. However, the effect of namesaking often appeared significant only in interaction with specific predictors, such as sex and primogeniture. It suggests instead that namesaking has an additive effect—it enhances the effect of biological factors on parental investment. In general, we found evidence for the bias in parental investment linked to name similarity among both parents, and support for the hypothesis that namesaking serves as a mechanism to increase paternity confidence and, thus, paternal investment. The effect of namesaking influences only certain types of parental investment—namely, those at the level of relationship quality. In addition, nonheterosexual orientation was the strongest negative predictor of paternal investment. Our study extends the research on parental investment by showing that cultural mechanisms, such as namesaking, can also exert some influence on parental rearing behavior. (shrink)

Whereas women are sure of their biological maternity, men can never be fully certain of paternity and instead need to rely on indirect cues to assess whether they are likely to be father of their putative children. According to the psychological literature, men commonly use the information on the resemblance of offspring to self as an indicator of genetic relatedness. It seems, however, that in the absence of such a resemblance, similarity between a mother and a child might be important, (...) because a man has additional reason to doubt his own biological paternity when the child is dissimilar to his partner. This assumption has been verified in two empirical studies. (shrink)