Hung I-Tzu, Stringaris Argyris, Liu Chang, Ganiban Jody M, Saudino Kimberly J
Department of Psychological and Brain Sciences, Boston University.
Department of Clinical, Educational and Health Psychology, Division of Psychology and Language Sciences, University College London.
J Clin Child Adolesc Psychol. 2025 Apr 22:1-12. doi: 10.1080/15374416.2025.2484799.
Irritability is genetically influenced and is associated with internalizing and externalizing psychopathology. However, little is known about the etiology of the development of irritability in the preschool period. The present study examined this from rank-order stability and developmental trajectories perspectives.
The irritability of 310 same-sex twin pairs (monozygotic = 123; dizygotic = 187; 51% female) was longitudinally assessed at ages 3, 4 and 5 years via parent-reports on the Child Behavior Checklist. Biometric Cholesky models and latent growth curve models were used to examine genetic and environmental influences on both the rank-order stability and instability, and within individual changes in levels of irritability across age (i.e. developmental trajectories), respectively.
The heritability of irritability ranged from 53% to 60%, with the remaining variances explained by nonshared environmental influences. Age-to-age stability was largely due to genetic influences. Novel genetic and nonshared environmental effects emerged at ages 4 and 5, indicating genetic and environmental contributions to instability. Approximately 42% and 22% of genetic influences at ages 4 and 5, respectively, were independent of prior ages, and over 85% of nonshared environmental influences were age-specific. Individual differences in developmental trajectories of irritability were entirely due to nonshared environmental influences.
The rank-order stability of irritability and within-individual change in levels of irritability across age are governed by different etiological processes, emphasizing the importance of examining development from multiple perspectives. Both perspectives highlight the role of nonshared environmental factors in early irritability development. Interventions could benefit from leveraging these factors to redirect early irritability development.
易怒受遗传影响，且与内化和外化心理病理学相关。然而，对于学龄前儿童易怒情绪发展的病因知之甚少。本研究从等级顺序稳定性和发展轨迹的角度对此进行了探讨。
通过家长对儿童行为量表的报告，对310对同性双胞胎（单卵双胞胎 = 123对；双卵双胞胎 = 187对；51%为女性）在3岁、4岁和5岁时的易怒情绪进行纵向评估。生物统计学Cholesky模型和潜在生长曲线模型分别用于检验遗传和环境对等级顺序稳定性和不稳定性以及个体易怒情绪水平随年龄变化（即发展轨迹）的影响。
易怒情绪的遗传度在53%至60%之间，其余变异由非共享环境影响解释。年龄间的稳定性很大程度上归因于遗传影响。新的遗传和非共享环境效应在4岁和5岁时出现，表明遗传和环境对不稳定性有贡献。4岁和5岁时分别约42%和22%的遗传影响独立于先前年龄，超过85%的非共享环境影响是特定年龄的。易怒情绪发展轨迹的个体差异完全归因于非共享环境影响。
易怒情绪的等级顺序稳定性和个体易怒情绪水平随年龄的变化受不同的病因过程支配，强调了从多个角度研究发展的重要性。这两个角度都突出了非共享环境因素在早期易怒情绪发展中的作用。干预措施可受益于利用这些因素来引导早期易怒情绪的发展。
