In a cluster randomized controlled trial, we examined the effect of limiting parents’ and children’s screen media use during leisure time on the amount of behavioral synchrony in physical behaviors and family cohesion. Compared with the control group, the intervention significantly increased instances where parent-child dyads exhibited behavioral synchrony in objectively assessed physical behaviors during their shared awake leisure time, as evidenced by both direct matching analysis and the TWED and OM sequence analyses. These analyses collectively demonstrated an increased similarity in physical behaviors within the screen reduction group, whereas the control group exhibited no significant change. The direct matching effect size corresponds to a notable 30% mean increase in time where children and parents displayed concurrent active behaviors. Parent-reported perceptions of changes in the family's activities and time spent together among participants in the screen reduction group further substantiate the idea of increased family time following a reduction in screen media use. Activities such as collaborating on everyday tasks and conversations within the family were reported to have risen in most participating families. To the best of our knowledge this is the first randomized trial to investigate whether limiting screen media use in families with children affect both the behavioral synchrony in objectively measured activities among children and their parents, and the cohesion within the family.
In a previous study examining joint physical activity and sedentary behavior among 291 pairs of parent and children aged 8–14 years who both wore an accelerometer and global positioning systems (GPS) device over the same 7-day period, the results showed that parents and children spent a mean of 92.9 min/day in sedentary behavior and 2.4 min/day of moderate-to-vigorous physical activity together during non-school waking hours [11]. When aggregating seconds over waking leisure hours, during which parents and children are engaged in the same activity, each dyad in our study spent an average of 108 min/day on sedentary activities and 7.7 min/day on running or walking at baseline, closely aligning with findings from previous research. This may indicate that our approach for estimating the amount of time spent on activity types where parents and children engage together in shared leisure time is satisfactory. However, despite the presence of objective data indicating synchrony in the physical activity behavior of parents and children, we cannot conclusively determine if it accurately reflects their social engagement. Nevertheless, it is reasonable to presume that the analysis in the current study captures certain patterns in the engagement between parent-child dyads.
Overall, the results suggest that limiting screen media use results in a greater behavioral synchrony in physical activity between parents and their children. This increased synchrony could serve as an important mechanism for reinforcing social bonds within the family. To further investigate the effect of the intervention on family relationship parents completed questionnaires concerning this issue. The analyses showed that limiting screen media use in families with children enhanced family cohesion by increasing time spent together as a family. A study in 2023 found that the time parents spend with children is crucial for children’s growth and wellbeing [12]. This could be attributed to the fact that children require emotional support from their parents, and parents play a crucial role in shaping the emotional and psychological wellbeing of their children [12]. Nevertheless, the wellbeing of children is not solely determined by the amount of time parents spend with them, but also by the quality of the interaction. As mentioned previously, two recently conducted systematic reviews showed that an individual’s use of screen media devices is related to less meaningful face-to-face interactions and more conflicts in the family [1, 8], which is in accordance with the results from the current study. Meaningful face-to-face interactions and social connections in families are crucial as positive family relationships are associated with better mental health later in life [2, 3]. Furthermore, previous studies have shown that adolescents perceiving that parents are using or being distracted by their phone when interacting with their child, have a higher level of e.g. depressive symptoms and anxiety [13, 14]. This is supported by our recent cross-sectional analysis in a population-based sample of Danish 7-year-old children, which revealed a dose-dependent relationship between higher maternal smartphone addiction scores and increased behavioral problems in children, including externalizing and internalizing difficulties [15], underscoring the broader implications of digital screen use on child development and family dynamics.
A strength of the current study is the experimental design used to investigate if changing screen media use habits in families with children will impact the amount of behavioral synchrony within parent-child dyads and family cohesion. In this experimental design, known and unknown confounding factors are expected to be equally distributed between the intervention and control group. Furthermore, a strength of the current study is the use of objectively measured physical activity behaviors and successful compliance with the screen reduction intervention, as evidenced by objectively measured screen use. Finally, the included participants and those who were non-eligible had similar background characteristics [16], which suggests that our findings may be broadly applicable across diverse family contexts and demographics within the types of families sampled for the population-based survey described in the methods.
Despite the strengths, the current study has some limitations. One limitation is that blinding of participants to the intervention was not possible in the current study. As previously reported it was found that compliance to the intervention group was high, however those in the control group slightly reduced their screen media use during the two week period even though they were instructed to continue with their usual screen media behaviors [16]. A limitation of the direct matching analysis, where seconds are matched 1:1 between parent and child, may be the potential underestimation of behavioral synchrony in active behaviors due to the time-lag to synchrony, i.e. the lag of seconds between change in one person’s behavior and parallel change in another person’s behaviors [6]. Also, the initial offset and drift in the real time clock between the accelerometers attached to the parent and child may also result in underestimation of behavioral synchrony [17]. However, the sequence analysis using TWED, which allows incorporating variations in behavior timing between the child and parent yielded similar results. In addition, while the accelerometry data indicate whether parents and children exhibited similar classified behaviors at a specific times of the day, they do not confirm whether they were physically together during those times. Future studies may benefit from collecting this information e.g., by using self-reported diaries, GPS, or video. Moreover, the present study has limitations in terms of measuring family cohesion through self-reports and solely within the intervention group. The parents were aware of their randomization into the intervention group, which may potentially influence their reports of family cohesion. The absence of family cohesion reports in the control group, prevents us from comparing the two groups. As a result, we cannot determine whether the observed changes in family cohesion are a direct result of the intervention.
In conclusion, the results from this cluster randomized controlled trial showed that limiting screen media use in families with children led to a significant increase in the behavioral synchrony in physical activity behaviors between parents and children during waking leisure time where they have the possibility to spend time together. Furthermore, parents in the screen reduction group reported perceived improvements in family cohesion, primarily attributed to spending more time together as a family. While direct comparisons with the control group were not feasible due to the nature of the questions, self-reported observations in the intervention group highlight the potential positive impact of reducing screen time on family relationships. Our study underscores the importance of balancing screen use within the family setting, pointing to its significant role in enhancing parent-child interactions and fostering a cohesive family environment, which are key factors affecting children’s development and long-term well-being.