If you need an IQ score for your son to get into a particular program now, then go for the testing. If it is for you to find what his strengths and weaknesses are, then it is better to wait until the child is 8 years old - the reason being lack of maturity at ages below this. I had my child tested at 4 and am waiting until he is 7-8 to get retested because I felt that he lacked maturity and was prone to chatting a lot etc during the testing - which ofcourse affects a the parts of the IQ test that measure speed.
