Yes. This happened with our son when he was tested as a 3 year old. Whether a kid gets the 'yips' or does it on purpose it can happen. Fortunately our tester (from the Hoagies page) was able to recognize something was up when our guy was dead average on one verbal subtest and hit the ceiling on another. He did ok on the other stuff and we had enough to place him in the "gifted" bucket.
It maybe a self defense mechanism - nails that stick up are often not treated kindly.
If you can find a gifted program or camp or something it would be interested in to put him in with other kids who are more likely to be peers.
