I have observed this phenomena. In addition to fear of failure as mentioned in the article smart people often also tend to be over sensitive which occupies enough brain processing cycles and memory, leaving them vulnerable to failure. The second factor kicks in particularly when the stakes are high. Sometimes it is better to be less gifted.
No I do not have this backed by randomized double-blind trial just evidence based.

Smart People Choke Under Pressure

People perceived as the most likely to succeed might also be the most likely to crumble under pressure.

A new 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.