Abstract
1- Introduction
2- Methods
3- Results
4- Discussion
References
Abstract
Children who grow up in neighborhoods with more green vegetation show enhanced cognitive development in specific domains over short timespans. However, it is unknown if neighborhood greenery per se is uniquely predictive of children's overall cognitive development measured across many years. The E-Risk Longitudinal Study, a nationally representative 1994-5 birth-cohort of children in Britain (n = 1658 urban and suburban-dwelling participants), was used to test whether residential neighborhood greenery uniquely predicts children's cognitive development across childhood and adolescence. Greenery exposure was assessed from ages 5 to 18 using the satellite imagery-based normalized difference vegetation index (NDVI) in 1-mile buffers around the home. Fluid and crystalized intellectual performance was assessed in the home at ages 5, 12, and 18 using the Wechsler Intelligence Scale, and executive function, working memory, and attention ability were assessed in the home at age 18 using the Cambridge Neuropsychological Test Automated Battery. Children living in residences surrounded by more neighborhood greenery scored significantly higher, on average, on IQ measures at all ages. However, the association between greenery and cognitive measures did not hold after accounting for family or neighborhood socioeconomic status. After adjustment for study covariates, child greenery exposure was not a significant predictor of longitudinal increases in IQ across childhood and adolescence or of executive function, working memory, or attention ability at age 18. Children raised in greener neighborhoods exhibit better overall cognitive ability, but the association is likely accounted for by family and neighborhood socioeconomic factors.
Introduction
Children who grow up in more versus less affluent neighborhoods exhibit better physical, psychological, and cognitive outcomes (Leventhal et al., 2015). Neighborhood socioeconomic status is one of the most frequently measured and consistent predictors of children's outcomes, even after family-level influences are taken in to account (Brooks-Gunn et al., 1993). For the most part, the specific dimensions of neighborhoods that support healthy child development remain poorly characterized (Minh et al., 2017). Prior research has focused primarily on the influence of negative features of children's built and social neighborhood environments, including physical decay, neighborhood disorder and crime, and a lack of social cohesion (Galster, 2012; Ross et al., 2001; Sampson and Groves, 1989). However, intriguing new findings are emerging regarding the potential role of positive features of children's built environments on cognition and health. A number of recent studies have reported positive associations between neighborhood greenery, or the amount of leafy-green vegetation growing within a neighborhood, and children's scores on cognitive and academic tests in urban and suburban settings (Dadvand et al., 2015, 2017; 2018; Flouri et al., 2018; Hodson and Sander, 2017; Kuo et al., 2018; Kweon et al., 2017; Matsuoka, 2010; Sivarajah et al., 2018; Wu et al., 2014). These findings raise the exciting possibility that children may experience cognitive benefits from spending time in or near “greenery” (Collado and Staats, 2016; Keijzer et al., 2016), and that “greening” vegetation-deprived urban neighborhoods may result in improved cognitive outcomes for children.