Preprint (accepted version) - Vrolijk et al. (2021) - Parent-Child Personality Similarity and Differential Autonomy Support Towards Siblings

Since parental differential treatment is related to more adjustment difficulties over and above main effects of parental treatment, it is important to understand under what conditions differential parenting is likely to occur. Using a within-family design, this study focused on between-sibling differences in parent-child personality similarity as a potential predictor of differential autonomy support from fathers and mothers. Longitudinal data (6 annual waves) of 497 target adolescents (56.9% boys, Mage at T1 = 13.03), one of their siblings (N = 416, Mage at T1 = 14.92), their fathers (N = 446, Mage at T1 = 46.74), and their mothers (N = 495, Mage at T1 = 44.41) were used. Parent-child personality similarity was determined based on distinctive profile correlations using the Big Five personality inventory. Structural Equation Modeling showed that the association between sibling differences in mother-child similarity and maternal autonomy support was positive and significant at the between-family level, and not at the within-family level. This means that, in families where one sibling was relatively more similar to the mother, the sibling with closer resemblance to the mother received relatively more autonomy support. No significant effects were found for fathers’ differential autonomy support. The present study highlights the importance of considering parent-child similarity in personality for understanding differences between siblings in maternal autonomy support.