Tia Ghose, LiveScience on a vision test which can predict IQ:
The test asked users to spot the direction of motion on a series of black-and-white stripes on a screen. Sometimes, the lines formed inside a small central circle, and other times, they were large stripes that took up the entire screen. Participants also completed a short IQ test.
The team noticed that people with higher IQs were good at spotting motion in the small circles, but terrible at detecting motion in the larger black-and-white stripes.
How smart are zebras?