I have two kids who are gifted acedimcally, but due to a heads up on boys, slow maturation and social issues, I held them both out a year. They had late birthdays (late August was one, November was another--back then the deadline for kindergarten was Dec. 1st). It worked out well to hold them back and neither was a behavior problem due to giftedness. I think, in my opinion, it's unecessary pressure to put on a child who is already struggling. In my decision to hold the boys back (both with IQ's over 130), I read a lot of literature and was surprised to find that the older the child is, regarding his classmates,the better he did in school. As for the gifted program, both of my kids were in it, and it was a lot more homework!