British Journal of Educational Psychology | Volume 77, Issue 4 (24th December 2010)
In a study of 148 students from eight primary schools across Scotland, researchers at the University of Dundee found significant gains in cognitive ability for those exposed 16 months of weekly of philosophy sessions – compared to a control group . Two years later a follow-up study found that these benefits continued into secondary schools.
(Topping & Trickey, 2010)
Read more here: Topping, K. J., & Trickey, S. (2007). Collaborative philosophical inquiry for schoolchildren: Cognitive gains at 2‐year follow‐up. British Journal of Educational Psychology, 77(4), 787-796.