That doesn't jive with my experience. When I was growing up in Ontario, there was a program at my high school that put students going through the gifted program (from elementary) together with students who tested as excelling at math & science in grade 8 into the same program. I never felt like the "gifted" students as a cohort excelled in any significant way (overall grades, aptitude for any specific topic, etc). Now the data sample here is obviously small & anectodal, but to my knowledge this is supported by scientific studies on the topic of gifted programs.