The answer to the question in the headline is "no". The line of argument used is extraordinarily tenuous: first it argues that reaction time is a good proxy for

The answer to the question in the headline is "no". The line of argument used is extraordinarily tenuous: first it argues that reaction time is a good proxy for intelligence, then it collects different reaction-time studies, weights them by sample size, and computes a correlation. Unfortunately, if you look at the main graph of the paper, it looks like a trend-line drawn through noise. But! Because of the sample-size weighting, the data is dominated by a single study in 1889, which had 3410 participants (the largest out of 16) and an unusually fast reaction time (the fastest). They then use frequentist statistics to sneak in the assumption that reaction time varies only with different subjects and populations, and not with different test-apparatus and methodology, arriving at a "significant at p=.003" result which I have no confidence in.