OP is playing with fire. It's quite dangerous to study human intelligence because there's a lot of results that you might accidentally stumble on, which can be

OP is playing with fire. It's quite dangerous to study human intelligence because there's a lot of results that you might accidentally stumble on, which can be mistaken for racism, or worse, be exploited by racists. Even if you stumble on such facts accidentally, it can very well damage your academic prospects (and sometimes non-academic prospects as well ... in places like Silicon Valley). Many years ago I had a friend who was studying an unrelated topic at University (he was trying to figure out how to test for future programming aptitude via a purely paper test). He was administering the paper tests to students with no programming experience before their first programming class, and then studying the correlation between various paper tests and final grades in programming projects in courses (including grad courses) over time. He found some quite good paper tests that correlated quite nicely with future grades on programming projects ... but a faculty advisor pointed out that the results of the paper test were also strongly correlated with some politically sensitive student categories. My friend abandoned the project because when it was pointed out like that, it was quite clear he was producing results that could be exploited to create a selection criteria he was not comfortable with endorsing.