中文摘要
本研究利用社会计量数据表明,课堂中的社会联系会塑造由受虐待和被忽视同伴所引发的对认知成就的负外部性的扩散。我们发现,与社会距离同受虐待和被忽视同伴最近的学生所受到的负面效应最强。负外部性的消退率表现为:与受虐待和被忽视的同伴相距三个同伴,等同于没有此类同伴。尽管效应—距离之间的反向关系同时适用于言语能力与数字能力,但其传导机制不同。受虐待和被忽视同伴较低的言语能力会损害其朋友的言语能力,而损害同学数字能力的则是破坏性行为本身。
Abstract
This study uses sociometric data to show that social connections in the classroom shape the diffusion of the negative externalities on cognitive achievement generated by abused and neglected peers. We find the strongest negative effects for students who are socially closest to the abused and neglected peer. The fade‐out rate of the negative externality is such that being three peers away from an abused and neglected peer is equivalent to having no such peers. Although the inverse effect‐distance relation applies to both verbal and numeric ability, it is conferred through different mechanisms. The abused and neglected peer's lower verbal ability harms her friends' verbal ability, whereas it is the disruptiveness itself that harms classmates' numeric ability.