Liu Chang, Zheng Yao, Ganiban Jody M, Saudino Kimberly J
Department of Psychological and Brain Sciences, George Washington University, Washington, DC, USA.
Department of Psychology, University of Alberta, Edmonton, AB, Canada.
J Child Psychol Psychiatry. 2023 Jan;64(1):59-70. doi: 10.1111/jcpp.13667. Epub 2022 Jul 13.
Preschoolers' temperament characteristics are associated with children's long-term development. Such links underscore the importance of understanding factors that shape temperament during preschool. This is the first study to examine genetic and environmental sources of developmental growth in three temperament dimensions: surgency, negative affectivity, and effortful control, during the preschool period.
Biometric latent growth curve modeling was used to examine genetic, shared, and nonshared environmental contributions to the invariant level of and developmental growth in temperament, using a sample of 310 same-sex twin pairs (MZ = 123, DZ = 187) assessed at 3, 4, and 5 years of age. Temperament was assessed using primary caregiver's report on the Child Behavior Questionnaire-Short Form.
All three temperament dimensions demonstrated linear increases from ages 3 to 5 years. The invariant levels of all three temperament dimensions were explained by genetic and nonshared environmental factors. Growth in surgency was fully explained by nonshared environmental factors, while growth in negative affectivity was mainly explained by genetic factors. Growth in effortful control was explained by genetic and nonshared environmental factors, although neither were significant due to large bootstrap standard errors. For negative affectivity and effortful control, the genetic factors that contributed to developmental growth were independent from those associated with their invariant levels.
Collectively, these findings indicate that both genetic and nonshared environmental factors play important roles in the invariant levels of temperament. Findings also accord a critical role of children's nonshared environment in the development of surgency and to a lesser extent negative affectivity and effortful control. It is also notable that novel genetic effects contribute to developmental growth in negative affectivity and effortful control as children age, emphasizing the importance of integrating developmental models in genetic research.
学龄前儿童的气质特征与儿童的长期发展相关。这些联系凸显了了解在学龄前塑造气质的因素的重要性。这是第一项研究学龄前阶段三个气质维度（外向性、消极情绪性和努力控制）发展增长的遗传和环境来源的研究。
采用生物特征潜在增长曲线模型，以310对同性双胞胎（同卵双胞胎=123对，异卵双胞胎=187对）为样本，这些双胞胎在3岁、4岁和5岁时接受评估，研究遗传、共同和非共同环境对气质的不变水平和发展增长的贡献。气质通过主要照顾者对儿童行为问卷简表的报告进行评估。
所有三个气质维度在3至5岁之间均呈线性增长。所有三个气质维度的不变水平由遗传和非共同环境因素解释。外向性的增长完全由非共同环境因素解释，而消极情绪性的增长主要由遗传因素解释。努力控制的增长由遗传和非共同环境因素解释，尽管由于较大的自助标准误差，两者均不显著。对于消极情绪性和努力控制，导致发展增长的遗传因素与其不变水平相关的遗传因素无关。
总体而言，这些发现表明遗传和非共同环境因素在气质的不变水平中都起着重要作用。研究结果还表明儿童的非共同环境在外向性发展中起着关键作用，在较小程度上对消极情绪性和努力控制也有作用。同样值得注意的是，随着儿童年龄的增长，新的遗传效应有助于消极情绪性和努力控制的发展增长，强调了在遗传研究中整合发展模型的重要性。
