Kids who are exposed to nature are more relaxed and attentive, this improves learning and performance in school.
Taylor, A. F., Kuo, F. E. (2009). Children with attention deficits concentrate better after a walk in the park. Journal of Attention Disorders. 12(5): 402-409.
Matsuoka, Rodney H. 2010."Student Performance and High School Landscapes: Examining the Links. 2010." Landscape and Urban Planning 97 (2010): 273-282. Elsevier. Web. 16 February 2016.
Tennessen, Carolyn M. and Bernadine Cimprich. 1995. "Views to Nature: Effects on Attention." Journal of Environmental Psychology 15 (1995): 77-85. ScienceDirect. Web. 16 February 2016.