Predictors of First-born Behaviour Toward Newborn Siblings

• In Event: Becoming an Older Sibling: The Role of Parents Across Cultures

Abstract

Introduction: One of the most influential relationships one can experience is with a sibling. Siblings influence each other’s development by being role models, as well as frequent social partners who engage in emotionally uninhibited interactions (McHale et al., 2006). However, most family research has focused on marital and/or parent-child relationships. There is a need for further research on sibling relationships (Whiteman et al., 2011), considering early sibling relationship quality predicts long-term outcomes (Brody, 2004; Buist et al., 2013; Dunn et al., 1994). Even before birth, parents question how their first-born child will react to a sibling, and how they can make this transition smoother. To better understand these factors, we investigated the early predictors of first-born behaviours towards newborn siblings. Specifically, we hypothesized that older siblings’ temperament and gender, as well as marital quality and mother-child relationship quality, would predict firstborn behaviours towards newborn siblings.
Method: The data are from a study of 45 mothers (Mage= 34.78 years; SDage = 3.86 years) and their typically developing children (Mchild age=32.26 months; SDage = 6.27 months; 26 boys and 19 girls) conducted in Sussex, UK from 2018-2021, with two time points. At Time 1, mothers were in their third trimester of pregnancy (M= 33.43 weeks; SD = 4.45 weeks), and Time 2 was scheduled 4 months after the due date. The Time 1 data was composed of home visits. The visits were conducted by two extensively trained researchers and lasted 90-120 minutes. During the home visit, mothers and their children were invited to complete play sessions, which were videotaped and coded after the visits. Mothers were also interviewed and completed several questionnaires. When the visit was completed, the two researchers agreed on ratings of the child’s temperament. The procedure of the Time 2 data collection was similar to Time 1 with an additional questionnaire about the new sibling relationship. However, we had to stop home visits due to COVID-19. Therefore, we sent mothers the questionnaires online; all Time 2 data was maternal self-reports.
Results: Using multiple regression analysis, sibling behaviour (Time 2) was predicted from child gender, child temperament, marital quality, and observed mother-child relationship quality, all measured at the first time point. Our hypothesis was partially supported. Girls and children with easier temperaments tended to show more positivity towards their newborn sibling 4 months after birth. In addition, better marital quality predicted less rivalrous first-born behaviours toward siblings.
Discussion and conclusion: The findings highlight the importance of studying early first-born behaviours toward siblings to understand the origins of sibling relationship quality during the stressful period of transition, with increasing family complexity. The study extends the literature on early predictors of first-born children’s behaviours toward their newborn siblings and may inform future intervention programs such that targeting marital quality and parenting during pregnancy may decrease sibling rivalry.

Authors

• Sumeyra Yalcintas, University of Sussex
  Presenting Author

• Alison Pike, University of Sussex