An MIT PhD engineer dad was recounting an old saw about how MIT students can't write and Harvard students can't count and it made me chuckle because I am a Harvard grad who counts on her fingers.
Like the old MIT-Harvard rivalry, there's often a cortical battle for resources between spatial and verbal / visual "picture" thinking. In studies of spatial experts, high levels of spatial expertise were correlated with lower levels of verbal fluency, auditory verbal memory, and visual memory (for more, read here. But these studies, if you look at mathematicians and physicists talking about their thought processes (see Hadamard's Psychology of invention. From the mathematician Hadamard: "I insist that words are totally absent from mind when I really think...even after reading or hearing a question, every word disappears at the very moment I am beginning to think it over; words do not reappear in my consciousness before I have accomplished or given up the research...I fully agree with Schopenhauer when he writes, "Thoughts die the moment they are embodied into words." Well no wonder MIT students can't write. In fact, they may take solace in the words of polymath Francis Galton: "It is a serious drawback to me in writing...that I do not so easily think in words as otherwise. It often happens that after being hard at work, and having arrived at results that are perfectly clear and satisfactory to myself, when I try to express them in language I feel that I must begin by putting myself upon quite another intellectual plane. I have to translate my thoughts into a language that does not run very evenly with them. I therefore waste a vast deal of time in seeking for appropriate words and phrases, and am conscious, when required to speak on a sudden, of being often very obscure..." If you look at the SAT subtest scores of MIT and Harvard students (25th percentile listed here - because 75th percentile was clustered at 800), MIT students are indeed weakest at reading and writing (not surprising you find many dyslexic engineers, mathematicians, physicists at MIT).
If you're an MIT student, Harvard students really may seem bad at math. The more uniform differences between reading, math, and science suggest more verbal (fewer spatial) left hemispheric types at Harvard.
There aren't any studies yet comparing the math abilities of highly verbal thinkers but if you superimpose test subjects doing verbal reasoning tasks (green) with estimations of nummber (red) - the areas really are distinct. And there are certainly plenty of famous highly verbal thinkers (for instance the polyglot Max Muller) who have gone on record saying that they didn't think that thinking could exist separate from words - definitely from the descriptions of spatial mathematicians and scientists above. We don't know how Muller did with Math, but certainly the multi-talented author, linguist, and etymologist C.S. Lewis was notoriously bad at math and simple calculations. He failed the mathematics part of college entrance exams twice, and was only allowed into college without passing math because he had served in WWI.
Spatial Expertise Gray Matter pdf
Causal / Verbal Reasoning pdf
fMRI of Dyscalculia pdf
C.S. Lewis and Math