A no brainer. Pressure chokes all, but its worse if you have high IQ. "People perceived as the most likely to succeed might also be the most likely to crumble under pressure. This study finds that individuals with high working-memory capacity, which normally allows them to excel, crack under pressure and do worse on simple exams than when allowed to work with no constraints. Those with less capacity score low, too, but they tend not to be affected by pressure."   read more »