We are about to test my DS6 (by school decision). DD was also tested at 6, though she was an older 6 (midway through 1st, rather than summer of K like DS). I felt DD, who has decent self-control in situations like this, was a little young, and I am now really feeling like DS is still too young, after trying him out on some practice questions (obviously, I am not a psychologist). I can't imagine testing a 4yo.
I feel like DD would have attended beautifully to an IQ test at age 8 and would have given the test her full attention; she had the maturity by then. Of course, as has been pointed out, that's a lot of lost time in school. I don't know the answer. It is/was obvious that both of my children needed more, starting in K.
