Reaction time is perhaps the most physiological, culture fair measure of intelligence. If your reaction time is slow, it means your brain is probably slow, and you’re deficient in a major component of intelligence. Of course reaction time is only moderately g loaded, so don’t be too depressed if you take this test and find out your reaction time is way slower than you thought. The great thing about this test is that it averages your 5 scores for you. Maybe practice for about five minutes to make sure you’re used to the test and know how it works, and then once you feel comfortable, do an official five trials and consider the average the computer calculates, your official average reaction time.