Children who spend 60 minutes daily in nature have a 50% lower risk of mental health issues, with the greatest benefits for children from lower-income householdsSocioeconomically disadvantaged youth face a greater risk of mental health challenges than their more advantaged peers. Existing evidence suggests that exposure to natural environments is a potentially important contributor to mental health. Research has also identified an “equigenic effect,” whereby exposure to nature may reduce health inequalities by disproportionately benefiting disadvantaged groups. However, most research has relied on indirect measures of nature exposure, such as the availability of green space within residential neighborhoods. Such measures do not capture children’s actual time spent in natural environments or the types of activities they engage in. To address these limitations, this study used GPS and accelerometry data from a nationally representative sample of Scottish children to objectively quantify their use of natural environments and examine its relationship with mental well-being. Specifically, the study aimed to determine: (1) whether use of natural environments is associated with better mental well-being among children; (2) whether this relationship differs according to passive versus active use; and (3) whether the relationship between natural environment use and mental well-being varies by sex and socioeconomic position (SEP).
The study used data from Studying Physical Activity in Children’s Environments across Scotland (SPACES), a nationally representative cohort study. This study examined data collected on 640 children (age 10–11 years) between May 2015 and May 2016. The children wore an accelerometer and GPS device during waking hours for eight consecutive days to assess nature exposure and physical activity. Researchers combined GPS, land cover, and accelerometer data to determine whether children were in natural, man-made, or private garden environments and whether they were using those environments passively (sedentary and light activity) or actively (moderate and vigorous activity). Daily duration of total use, passive use, and active use were estimated and averaged for the eight days to determine each participant’s daily time in natural environments (“total use”) and daily time in natural environments at low PA states (“passive use”) and high PA states (“active use”). Child mental well-being was assessed with the Strengths and Difficulties Questionnaire (SDQ), completed by parents, which included subscales for emotional problems, peer problems, conduct problems, hyperactivity, and prosocial behavior. The SDQ was used to evaluate internalizing emotional difficulties, such as anxiety and depression, and externalizing behavioral difficulties, such as aggression and disruption. Statistical analysis was conducted to examine the relationships between exposure measures and mental well-being indicators, and to determine whether these relationships varied by SEP and sex. The analysis also controlled for factors that may influence mental well-being and nature exposure, including total PA, maternal age, residential urbanicity, time in private gardens, season, and residential nature exposure.
On average, children spent 79 minutes per day in natural environments and engaged in passive (sedentary to low-moderate intensity) activities 77% of the time. Results of the main analysis revealed that total use of natural environments was linked to a reduced likelihood of abnormal internalizing and externalizing outcomes. Notably, a 10-minute increase in total use was associated with a 10.5% lower risk of internalizing difficulties, and a 13.2% lower risk of externalizing behavioral difficulties. These findings indicate that approximately 63 minutes per day of natural environment use was associated with a 50% lower probability of abnormal internalizing outcomes, while approximately 49 minutes per day was associated with a 50% lower probability of abnormal externalizing outcomes. These relationships were consistent for both passive and active uses. The findings also did not vary based on sex; however, SEP-based differences were identified. While SEP did not change the relationship between nature use and internalizing problems, SEP was found to influence the relationships with externalizing and prosocial outcomes. Specifically, passive use of natural environments was linked to fewer externalizing problems among lower, but not higher, SEP children. Active use was linked to better prosocial outcomes among only low-SEP children, although this finding was less certain. Statistical models indicated that among children with low SEP, 50 minutes of passive time in natural environments was linked to a lower likelihood of abnormal externalizing behavior, bringing their predicted risk to a level similar to that of high-SEP children with no nature exposure. Similarly, about 40 minutes of active time in natural environments was linked to a higher likelihood of normal prosocial behavior among low SEP children, reaching a level similar to that predicted for high SEP children with no nature exposure.
The study provides robust evidence, based on direct measures of children’s engagement with nature, of an association between natural environment use and children’s mental well-being, as well as how this relationship varies by socioeconomic status. Notably, the findings suggest that spending approximately 60 minutes per day in natural environments is associated with a 50% lower risk of abnormal mental health outcomes. Further, both active and passive use of natural environments appear to offer greater benefits for children from lower socioeconomic backgrounds. These findings reveal an equigenic effect, suggesting that natural environments may help reduce disparities in mental health outcomes between socioeconomically advantaged and disadvantaged children. The findings also highlight the potential importance of passive engagement with nature. As the researchers note, “providing opportunities for quiet reflection and relaxation in nature may be as important as encouraging more vigorous activities.” This suggests that interventions designed to increase children’s engagement with nature should incorporate a range of experiences, including both calm, restorative activities and more physically active forms of engagement. Such approaches may be particularly valuable in disadvantaged communities, where access to nature may offer an opportunity to help reduce socioeconomic inequalities in child mental health.
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