"gifted child" programs can lead to by implicitly labeling some students as "ungifted" and isolating them from an enriched educational environment. factor analysis stereotype threat the flynn effect self-fulfilling prophecies reliability

I believe the answer is: self-fulfilling prophecies.

By separating the children into 'gifted' and 'non gifted' groups, we will teach the children in 'non gifted' group that they are inherently would never as good as the children in 'gifted' group.
This would make them more likely to make less effort and ending up self fulfilling their own failure.