Children's affect: Automated coding, context effects, relations with maternal affect, and heritability

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.