He is doing well academically, and I am afraid if they retain him, he will be bored and develop behavior problems. I volunteer in his classroom frequently and his behavior seems no different from his peers. My husband observes him at Cub Scouts, and says he acts just like the other little boys. Can a child be retained for developmental immaturity, and does that really help?
Research tells us that any retention increases the likelihood that a child will drop out of school when he or she reaches the legal age to do that. If a child is to be retained, however, kindergarten and first grade are the best years for that to happen.
Grade placement in most school districts is the decision of the principal, but most will not retain a child if the parents are opposed. Meet with the school staff and listen to what they have to say. Ask if there is any developmental testing available (the Gesell School Readiness Test is one example) that could be given to determine your son's readiness for second grade.
It's great that you and your husband have observed your son both in school and outside it. You may also want to observe the second grade classes at his school. Even though the children currently in second grade are a year older than your son, you will be able to get a good idea of the structure of the class and the teacher's expectations.