Green space makes for better students

We’ve been hearing for a while now how simply being around green space more can be beneficial. Early this year, for example, a study found that moving to areas with more trees and vegetation led to an immediate and prolonged improvement in mental health. Just looking at a tree every now and then seems to give us all a boost.

It’s not so far-fetched, then, that green space might yield improvements in our actual output into the world, along with those internal benefits. A new study, the first to examine green space in relation to school performance, found just that.

Researchers from Taiwan collaborated with others at Harvard, Brown, and elsewhere in the US and used remote sensing techniques to make the assessment. Satellite imagery can yield what is known as the Normalized Difference Vegetation Index, or NDVI; it is essentially a measure of light reflecting off of plants, used to determine how thick the vegetation is. The researchers used NDVI results at varying distances around 905 public elementary schools in Massachusetts, and compared them with standardized test results from third graders. The results are striking.

In short, more trees means higher scores. For example, the correlation coefficient between a 2000-foot NDVI “buffer” around a school and student scores was 0.42 for English and 0.32 for math, both of which are highly statistically significant. Those correlations diminish slightly as you move closer to the school; in other words, more vegetation in a school’s immediate vicinity is slightly less important than more vegetation stretched out farther from the school walls. The connection was greatest in March and July, and seemed to diminish or disappear in October.

The obvious “but wait!” question centers around the other variables that might connect to a greener school space. Schools in higher poverty/lower income areas are less likely to be surrounded by trees, so the researchers adjusted their analysis to account for median incomes (they performed a similar adjustment for gender of students). As you can see in the chart below, richer and poorer areas saw similar increases in scores with increasing NDVI. The results, the authors wrote, suggest “that surrounding greenness has approximately equal effects on student academic performance regardless of financial status or gender.”

This is limited both by lack of access to other variables such as parental education (which has been correlated with student achievement in the past), and by a lack of data on individual students’ scores. But overall, the authors call this a “robust finding,” and suggest more work be done to show just how far reaching the effect is.

It shouldn’t be surprising anymore that green spaces make us happier, healthier, and just generally better, but every time a hard finding on the topic pops up it seems incredible once again. Just being near nature is enough to bump up kids’ grades—though we’ll need more data to back this up, it probably can’t hurt to head out and look at some trees any chance you and your kids can get. – Dave Levitan | October 14 2014

Green spaces meant better scores for both richer and poorer areasSource: Wu CD, McNeely E, Cedeno-Laurent JG, et al (2014). Linking student performance in Massachusetts elementary schools with the “greenness” of school surroundings using remote sensing, PLoS One, 9 (9) e108548. DOI: 10.1371/journal.pone.0108548

Image:, Africa studio