Abstract
This study examined genetic and environmental influences on twins’ and parents’ positive and negative affect during a parent–child conflict discussion and a positive discussion, captured by automated facial coding. Associations with internalizing, externalizing, and ADHD symptoms were examined. Twins (N = 560 50.94%; female; Mage = 9.72, SD = .94; data collected 2017–2020) and parents (N = 302; 583 videos) were from socioeconomically diverse families, and primarily White (57.07%) or Hispanic (26.78%). Child and parent positive affect were influenced by the shared and nonshared environment and child negative affect was heritable, with similar etiology across tasks. Only child positive affect during the conflict discussion consistently related to lower internalizing, externalizing, and ADHD symptoms (R2: 1.3%–3.6% of variance). Findings support positive affect under stress as an environmentally influenced resilience factor.
Lay Summary
This study examined genetic and environmental influences on 9-year-old twin children’s positive affect (smiling, happiness) and negative affect (anger, sadness, fearfulness) during a challenging parent–child conflict discussion and a positive parent–child discussion. We used an AI method of automatically coding facial expressions. We also asked parents to report on their twins’ symptoms of internalizing (like depression), externalizing (like aggression), and ADHD using questionnaires. For twins, negative affect was partially genetically influenced. Twins’ positive affect was explained by environmental factors, and positive affect during the conflict discussion was related to lower symptoms. Parent affect was not strongly influenced by children’s genetically influenced characteristics. Our findings suggest that children’s ability to stay positive during a stressful parent–child interaction is both environmentally influenced and important for resilience.
