My 10 year old son, who is an only child, plays with kids younger than he is (6 & 7 year olds), when at home. He has one friend who is his age, but would rather play with the younger children than the kid his age. At school, he will play with other kids in his class. My son still likes to play with toy cars, legos, etc., where most of the boys his age are 'too old' to play with these kinds of toys. Developmentally, he is below grade level in reading (on 4th grade, but should be at 6th grade), but other than that there are no other delays. Should I be concerned about who he is choosing for his friends, based on their ages? The boys his age in the neighborhood are not ones to get in trouble, same as with the kids younger than he.