Recent social-demographic trends predict a growing importance of grandparents’ role in family wellbeing. Over the past years, the three-generational household arrangement has become more prevalent in western countries. However, the implications of three-generational household arrangements for children’s development are less known, particularly over children’s different ages. Using five waves of data from the British Millennium Cohort Study (MCS), we examine whether a three-generational arrangement influences children’s cognitive and behavioral outcomes and how these effects vary from early childhood to adolescence. Fixed effects regressions results reveal that three-generational household arrangement has a negative effect on children’s cognitive and behavioral outcomes in early childhood (ages 3 and 5), and such arrangement matters less for children during middle childhood and adolescence (ages 7, 11 and 14). This study illustrates heterogeneous influences of multigenerational household arrangement on children’s wellbeing across different developmental stages and calls for more thorough research on various multigenerational interactions and mechanisms that may underly such changing patterns.

最近的社会人口趋势预测祖父母在家庭幸福中的作用越来越重要。近年来，三代家庭的安排在西方国家越来越普遍。然而，三代家庭安排对儿童发展的影响鲜为人知，特别是对不同年龄的儿童。使用来自英国千禧年队列研究 (MCS) 的五波数据，我们研究了三代人的安排是否会影响儿童的认知和行为结果，以及这些影响如何从幼儿期到青春期发生变化。固定效应回归结果显示，三代家庭安排对儿童早期（3岁和5岁）的认知和行为结果有负面影响，而这种安排对儿童中期和青春期（7、11 和 14 岁）的影响较小。这项研究说明了多代家庭安排对不同发展阶段儿童福祉的异质影响，并呼吁对可能导致这种变化模式的各种多代互动和机制进行更深入的研究。