There are pros and cons for holding back. Just do your research before you do it. An informed decision is the best decision. Studies show the younger kids in a grade will have a higher IQ as an adult. The kids held back for the wrong reasons studies show will have a Lower IQ. I don't believe that IQ is a good measure of intelligence but it does make one wonder. There are too many studies that show many negatives for holding back for the wrong reasons like for sports. There are also psychological studies on the impact of a holdback who dominates in high school but can't dominate as a adult. Don't rely on a lacrosse coach to help make your decision. Talk to doctors, school officials and even a psychiatrist before you make such a life changing decision.