[MathGeek]

Originally Posted by MissSmallAimsSmall

"The present hypothesis suggests that these losses are in the areas of quantitative reasoning, analytic ability and the whole constellation of other cognitive-perceptual abilities associated with the field-dependent cognitive style. Marijuana might, thus selectively interfere, for example, with study of such subject matter areas as mathematics and engineering." - Marijuana and Perceptual Style: A Theoretical Note

This theory was experimentally confirmed in later studies:

An examination of the relationship between academic achievement and drug use in a wide range of students, Jeynes (2002) concluded that marijuana use, when examined alone, was statistically significantly related to lower standardized test scores in math, science, reading, and social studies. Average scores on the math comprehension test for marijuana users were further below the mean than on any other test... - An Updated Review of the Research on the Risks and Harms Associated to the Use of Marijuana