Is this a new student to your district? Aren't there any notes in his student file about this? I understand that this is his first year in your school, but doesn't he come from the school that feeds into yours? You should be able to contact them and get some sort of history that would help you out.
This could be many things. It wouldn't be fair of us to try to diagnose here. It sounds like the very least that could be done would be some non-judgmental conversation with mom and/or dad.
