The role of siblings' temperaments in predicting parental rejection toward firstborns during transition to siblinghood in Chinese families

This longitudinal study examined how interactions between both children's negative emotionality predicted parental rejection toward firstborns (Mage = 49.9 months; 55% boys) in 120 Chinese two-child families from 2016 to 2018 in Shanghai (mostly Han ethnicity). Parents reported firstborns' temperament prenatally, secondborns' temperament at 6 months postpartum, and parental rejection prenatally and at 1, 6, and 12 months postpartum. Regression analyses predicting parental rejection toward firstborns at 6 and 12 months postpartum from both children's temperaments controlled for two prior parental rejection. Higher negative emotionality in secondborns predicted greater maternal rejection toward firstborns at 6 months. At 12 months, this association emerged only when firstborns also showed high negative emotionality. No significant effects were observed for paternal rejection.