Objective It is to explore the intergenerational transmission effect of Phubbing and the causal relationship between the transmission and adolescents' home physical activity by cross-lagged study design.

Methods The phubbing scale and the international physical activity questionnaire-short form were used to conduct a three-month, two-stage follow-up investigation on 616 group of junior high school students family Adolescents: 48.21% boys, aged (13.17 ± 2.634) years old. Parents: aged (39.77 ± 4.692) years old.

Results For adolescents, the gender differences in adolescents' phubbing and their home physical activity were significant (P<0.01). Parental phubbing, adolescents' phubbing and their home physical activity had the transtemporal and stable significant correlations (P < 0.001). The cross-lagged analysis revealed that, parental phubbing could significantly predict adolescents' phubbing (β = 0.29, P < 0.001) and their home physical activity (β = −0.18, P< 0.001) in 3 months, and adolescents' phubbing could significantly predict their home physical activity (β = −0.30, P < 0.001) in 3 months. Besides, parental phubbing could not only directly affect their offspring' home physical activity, but indirectly restrict their offspring' home physical activities by influencing the offspring' phubbing.

Conclusion  Compared to male adolescents, female adolescents have more frequent phubbing and the lower level of home physical activity. There is an intergenerational transmission effect of phubbing among parents and their offspring. Moreover, this intergenerational transmission effect will have a negative impact on adolescents' home physical activity.