This study examined the “greenness-academic achievement” (G-AA) relationship in Chicago public schools, a predominantly urban, low-income, minority school district. A previous study focusing on this same district found no G-AA link, but that study did not distinguish between different types of vegetation, employed coarse measures of “greenness,” and did not consider potential interactions between green cover and student disadvantage. This study addressed each of these concerns and was framed around four primary aims: “to examine the relationship between greenness and academic achievement in the context of disadvantage; to determine the extent to which this relationship is driven by greenness immediately around schools versus in surrounding neighborhoods; to examine the contributions of different kinds of green cover to academic achievement; and to examine the relationship between school greenness and disadvantage.”
Greenness was assessed for each school for two types of green cover: tree canopy cover and grass/shrub cover. Greenness was also assessed for each school for three geographic zones: school catchment area, school zone (school grounds plus 25 m buffer around the school grounds), and school neighborhood (the area inside a school catchment but outside the school zone). Assessing greenness in these different zones allowed the researchers to examine the relative importance of school greenness and neighborhood greenness. School-level academic achievement was defined as the percentage of third graders performing at or above grade-level expectations as indicated by standardized reading and math scores. Additional data included in this study focused on school characteristics found to predict academic achievement. This data included socioeconomic status and race/ethnicity, percent of bilingual students, school size, percent of female students, and pupil/teacher ratio.
Analysis of the data showed that the more disadvantaged schools had less green in and immediately around their schoolyards than schools facing less disadvantage. Additionally, schools serving more white, well-off students had more tree cover than other schools. Extremely disadvantaged schools had only about half the amount of tree cover as the less disadvantaged schools. Findings also showed that measurements of green cover predicted statistically significantly better school performance on standardized tests of math and marginally statistically significant results for reading. These predictions held even after controlling for disadvantage and other school characteristics associated with academic performance.
Tree cover was a stronger predictor of academic achievement than other types of greenness. Additionally, school trees were more strongly linked to both reading and math scores than either neighborhood trees or trees in the catchment area as a whole. Results showed that other types of greenness (grass and shrub cover) were not related to academic achievement. Findings also showed that the association between greenness and academic performance vary by levels of disadvantage at the school.
These findings suggest that “greening has the potential to mitigate academic underachievement in high-poverty urban schools.” These findings also offer some guidance on where and what types of greening may be most beneficial for promoting academic achievement. This research calls attention to the fact that because “school trees might boost academic achievement, the paucity of tree cover in low-income areas is not merely an aesthetic issue but an important environmental justice issue”, as well.
Research Partner