The aim of this study was to test the relationship of theory of mind (ToM) and maternal emotional expressiveness with children's aggressive behaviours (i.e., relational aggression, physical aggression). ToM is vital to relational aggression, which involves harming others through purposeful manipulation and damaging peer relationships. However, little is known about how ToM and family emotional environment are interactively associated with aggressive behaviours. Fifty‐one Japanese children, aged 4 and 5 years, completed measures of ToM and receptive vocabulary. Mothers reported their emotional expressiveness towards their children and classroom teachers rated each child's aggressive behaviours. The results revealed that when boys have mature ToM and their mothers show high negative emotional expressiveness, they exhibit higher relational aggression in their peer relationships. Such interaction effect was not found for girls. The findings suggest that boys with mature ToM are likely to learn to use ToM for antisocial purposes via negative family emotional environments.

中文翻译：

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心理理论和母性情感表达与攻击性行为在日本幼儿中的关系：性别差异的影响

这项研究的目的是检验心理理论（ToM）和母亲情绪表达能力与儿童的攻击行为（即关系攻击，身体攻击）之间的关系。ToM对于关系攻击至关重要，它涉及通过有目的的操纵和破坏同伴关系来伤害他人。但是，关于ToM和家庭情感环境如何与攻击性行为交互关联的了解甚少。51名4岁和5岁的日本儿童完成了TOM和接受词汇量的测量。母亲们报告了他们对孩子的情感表现力，教室老师对每个孩子的攻击行为进行了评分。结果显示，当男孩有成熟的ToM并且母亲表现出很高的负面情绪表达能力时，他们在同伴关系中表现出较高的关系攻击性。对于女孩没有发现这种交互作用。研究结果表明，具有成熟ToM的男孩可能会通过负面的家庭情感环境学习将ToM用于反社会目的。