Children’s Exposure to Green Spaces May Improve Brain Development


Researchers in Spain have found that for 2nd-, 3rd- and 4th- graders, connecting with nature helps the growth of mental abilities. Tom Jacobs of Pacific Standard reports parents may want to be sure their children are receiving adequate access to the natural world.

A similar study took place last year and was published in the online journal PLoS One. It found that Massachusetts third-graders with greater “exposure to greenness show better academic performance in both English and math” and on standardized testing, according to Chih-Da Wu of National Chiayi University in Taiwan, even when factors such as race and parental income were controlled.

The researchers cite, among other things, “increased physical activity, increased social contracts, reduced psycho-physical stress and depression, decreased noise,” and lower levels of air pollution.

The Spanish researchers explained that contact with nature is believed to play an important and unique role in brain development. In the report, published in the Proceedings of the National Association of Sciences journal, they added that being in nature provides children the opportunity to engage, take risks, discover, create, obtain mastery and control, strengthen a sense of self, inspire a sense of wonder, and enhance psychological restoration.

“Our study showed a beneficial association between exposure to green space and cognitive development among schoolchildren,” writes a research team led by Payam Dadvand of Barcelona’s Centre for Research in Environmental Epidemiology. This is partly, but not entirely, explained by the fact that kids who get to play in nature are exposed to less air pollution than those who hang out on city streets.

Even being in the proximity of green spaces has been shown to increase physical activity, which, in turn, is associated with better cognitive function. Some past research suggests “microbial input” from being in a natural environment may have impact on brain development.

The greenery to which children were exposed even included the green spaces around their schools and neighborhood, as measured by satellite imagery. Those with lots of green and natural scenery showed better attention and a higher amount of “superior working memory.”

The researchers who were part of the study were not only from Spain, but also Norway and the US. They studied 2,593 seven to 10-year old children from 36 schools in Barcelona over the course of a year. Each student took four cognitive tests at three-month intervals.

Along with this, the authors used images taken by satellite to assess green space around each child’s home, neighborhood, and school, says Chris Mooney of The Washington Post.

The researchers also measured levels of “traffic-related air pollution” which tends to be lower in areas with more grass, trees, and plants. This factor made up 20% to 65% of the connection between greenery and cognitive development.

With these types of tests, children generally improve over time, but those with the most exposure to nature improved more, on average, in working memory, superior working memory, and attentiveness. The greenness of the area around the children’s homes was not as influential as the greenness along children’s commute to school and, and in particular, the greenness around the school. Other possible factors that cause green spaces to influence children’s cognitive function include less distracting noise and a better chance of outdoor exercise. Research shows that physical activity can boost learning and educational performance.

Harvard evolutionary biologist E.O. Wilson theorizes that since humans evolved in certain kinds of green landscapes, it is possible that we have a psychological need for them. One writer summarized the theory.

“If there is an evolutionary basis for biophilia, as asserted by E.O. Wilson… then contact with nature is a basic human need.”

The scientists also used teacher surveys, class observation, and testing to establish student performance, writes UPI’s Brooks Hays.

The authors say they will need to do more work in order to confirm their findings. Critics of the research have suggested that some extenuating factors, such as the mental health of the subjects or their parents, could explain differences in performance. Mental health was not taken into consideration as part of the study.

06 18, 2015