My 5 year old son keeps on throwing things at his classmates that result to hurting other kids. He is very competitive in school. He always wants to be the first in everything...first in arriving in school, first in finishing projects, first in brushing teeth after snack time, first in line,etc....The teacher says he does this because he is an only child and doesnt have any playmates at home, therefore he doesn't know how to interact with other kids and becomes competitive. Another thing is, he always throws up everytime he eats. Is this a sign that he has a behavioral disorder? Should I have him checked by a doctor? Im really worried...Hope someone can help!Thanks!