Emotion expression and the sibling dynamic in twin pairs: The role of early life temperament.

• In Event: 2-015 - Peer influences on child and adolescent social competencies: Evaluating genetic and environmental influences

Integrative Statement

Increasingly, research seeks to explore interactions among individual and relational factors influencing socioemotional development. Although many relationships contribute to socioemotional development, the understudied sibling relationship warrants further attention, as it fosters the skills necessary to navigate broader social contexts (Kramer, 2014). Given that children are active agents in the formation of relationships, an examination of how individual factors contribute to emotion expression and the sibling dynamic stands to enhance our understanding of the many factors influencing socioemotional development. Aim1 of the current study adopted a microanalytic focus, using actor-partner models to examine the degree to which negative emotions expressed over the course of a competitive game between twin siblings at 8 years were stable across observations for a single twin (actor effects) as well as reciprocally influenced by their cotwin’s negative emotions (partner effects). Early-life negative emotionality was examined as a moderator of sibling emotion dynamics. We hypothesized significant actor and partner effects on expressed negative emotion, with partner effects becoming more pronounced at higher levels of negative emotionality. Aim2 was to examine independent and shared genetic and environmental influences on early-life negative emotionality and sibling conflict at 8 years.

Participants were drawn from an ongoing longitudinal twin study based in the southwestern U.S. (Aim1 N=100 same-sex twins (52% female; 55% European-American, 20% Latino, 25% Other); Aim2 N=262 twins (54.6% female; 64.5% European-American, 16.4% Latino, 19.1% Other)). Negative emotionality was assessed at 12 and 30 months via mother-report on the Infant and Children’s Behavior Questionnaires (Garstein & Rothbart, 2003; Putnam & Rothbart, 2006) and mean composited. Mother-report of conflict via the Sibling Relationship Questionnaire (Furman & Buhrmester, 1985) and the observed Marble Game sibling competition were completed at 8 years. The competition was videotaped and facial expressions were coded for emotion across 50 trials using Emotient FACET (iMotions, 2016).

Results indicated a significant actor effect on expressed negative emotion (β = 0.17, p < .001) representing stability in expressed negative emotion across the sibling competition. Additionally, there was a trend towards moderation of the partner effect by early-life temperamental negative emotionality (β = 0.12, p = 0.10). Using the twin method, the best-fitting bivariate Cholesky decomposition (Figure 1) revealed high, independent genetic influence on negative emotionality in early life, while the shared covariance with sibling conflict at 8 years was entirely accounted for by the common environment. There was no evidence for the heritability of sibling conflict.

Results point to the stability of expressed negative emotion within a microanalytic framework, producing only tentative evidence for the influence of temperament on children’s emotional reactivity to their siblings. Additionally, shared environmental influences, rather than genetic factors, were found to explain associations between early-life temperament and sibling conflict at 8 years. This stands in contrast to prior research revealing genetic influences accounting for the association between concurrent temperament and sibling conflict in early childhood (Lemery & Goldsmith, 2001). Our findings suggest environmentally-based interventions designed to promote adaptive trajectories of social functioning may be promising for children exhibiting early-presenting dispositions to negative emotional reactivity.

Authors

• Veronica Oro, Arizona State University
  Presenting Author

• Leah D. Doane, Arizona State University
  Non-Presenting Author

• Kathryn Lemery-Chalfant, Arizona State University
  Non-Presenting Author