We had an IQ test as part of the performance review process in a company I worked in. It did not have any effect on the review, it was just there. The dudes with IQ above 120 were insufferable to work with. The dudes with IQ below 85 were insufferable to work with. Both managed to do about the same amount of work. The dudes who scored between 100-110 were a pleasure to work with, and practically carried the other two groups.