The impact of schoolyard greening on children's physical activity and socioemotional health: A systematic review of experimental studies
Greening of schoolyards can generate positive physical activity and socioemotional health outcomes for students
Numerous studies report a positive association between green schoolyards and students’ physical and mental health. The research methods used for most of these studies, however, are insufficient for establishing causality. This review, therefore, included only experimental studies that examined the impact of schoolyard greening on physical activity and socioemotional health in children.
Only six studies met the search criteria for this review. In addition to using an experimental design, studies included in this review (1) focused on children under the age of 18, (2) involved schools with green schoolyards, and (3) used pre-post assessments of physical activity (PA) and/or socioemotional health (SEH).
Two of the studies were conducted in North America; the other four in Europe. Two studies looked exclusively at SEH outcomes; the other four measured both SEH and PA outcomes. Four of the six studies used schoolyard greening interventions, which involved changing the outdoor school environment from a more traditional schoolyard to a more natural environment featuring a combination of natural elements (trees, bushes, sand, water, etc.). The other two studies used modified versions of the interventions – one adding AstroTurf in a playground reconstruction; the other using Social and Therapeutic Horticulture (STH) -- a recognized green space intervention-- with children experiencing behavioral, emotional, and social difficulties. Children involved with the STH program actively participated in the development of selected green spaces at their school. The age of participating children ranged from 2 to 15. Sample size varied from 36 to 437 children.
While most of the outcome measures for both PA and SEH showed beneficial changes due to greening, there were some exceptions. One study, for example, found that that greening of the schoolyard had positive impact on many SEH outcome measures, but not on emotional well-being or on children’s perceived restorative quality of the greened schoolyards. The study did indicate, however, that greening seems to promote restoration by replenishing depleted cognitive resources post-recess. This same study reported a negative effect on older children’s prosocial behaviors. Another study found that greening has positive effects on measures of SEH except in the area of executive functioning and two areas of perceived restorativeness (being away and coherence). There were some age and gender differences in PA outcomes, with younger children showing more PA benefits that older children. There was also evidence of a positive effect of greening on girls’ PA, while there was no such impact on boys.
Overall findings of this review indicate that schoolyard greening can generate positive physical activity and socioemotional health outcomes for students. These findings suggest that, due to children spending a considerable amount of time at school every day, greening schoolyards can help to reduce the health equity gaps and improve children’s health regardless of their backgrounds or neighborhood socioeconomic status.