This dissertation aims to address the gap in family research concerning the role of siblings in children’s social development. Firstborns’ interactions with their younger sibling and parenting... Show moreThis dissertation aims to address the gap in family research concerning the role of siblings in children’s social development. Firstborns’ interactions with their younger sibling and parenting towards all children in the family are investigated in a four-year longitudinal study following families with two children from the first birthday of the youngest child. In Chapter 2 the prediction of individual differences in sharing with a younger sibling by family and situational factors was investigated. In Chapter 3 the association between parental sensitivity towards both children and compliance and sharing behavior of the firstborn child was investigated. Chapter 4 focuses on sibling discipline and sibling support during parental limit-setting, and associations with inhibitory control, empathy, and gender. Finally, the effect of birth order on toddlers’ social development was examined with a longitudinal within-family design in Chapter 5. Show less
The development of self-regulation is one of the major challenges of a child’s healthy development. In the current thesis, the contribution and interplay of parental and biological factors in... Show moreThe development of self-regulation is one of the major challenges of a child’s healthy development. In the current thesis, the contribution and interplay of parental and biological factors in the development of self-regulation in preschoolers are studied in a large population-based cohort, the Generation R Study. We found that attachment insecurity in infancy was related to higher levels of toddler active resistance during Clean-Up. Maternal negative discipline was related to lower levels of committed compliance in toddlers, and the association between maternal positive discipline and child committed compliance was moderated by the child’s COMT rs4680 genotype, indicating that the association was stronger in children with the Met/Met variant than for children with other COMT genotypes. Maternal family-related stress during pregnancy predicted lower levels of toddler committed compliance through lower levels of maternal positive discipline. Maternal sensitivity was associated with lower levels of executive function problems and lower levels of internalizing problems in preschool age. In children with a relatively short corpus callosum in infancy, higher levels of maternal positive discipline predicted lower levels of inhibition problems. Our studies demonstrate the role of various aspects of positive parenting and mother-child relationship quality in preschool children’s regulation of emotions and behavior. Show less
