Underachievement rates among those gifted children

[pippin_999]

Last time I posted on this thread I proved I didn't know what I was 
talking about--and I appreciate Shaun pointing it out so gently. 

So I have been lurking since then, but I am curious about the 
50% statistic. If 50% of the gifted underachieve, how is that 
different from saying, for example, that 50% of drivers are worse 
than average, which is just what you would expect?

Pippin
probably asking a stupid question :-)