Hello Anonymous,
 
Thank you for writing your important question to JustAsk.  I commend you for being very much in tune with the needs of your son.  Since you use ASL fluently with your son I would think that language communication on a basic level is not an issue in the home, however, I am unclear if he is attending a school for the deaf, program for the hearing impaired in a public school or is mainstreamed.  If he is the only signing student within a hearing environment this may be part of the reason for his pushing, hitting, etc. behaviors.  If language barriers are the case then a class sign language series of lessons may be in order to help ameliorate the situation.  Sign language can be incorporated in a fairly easy way throughout his day, if this is the case.
 
However, given his other profile of Reactive Detachment Disorder, you may wish to have the special education team at school in conjunction with you develop a cooperative behavior plan.  This plan would be both at home and at school in order to send a clear signal to your son that you are very much in tandem with positive reinforcement and consequences for negative behaviors.  First, I would recommend that several behavioral observations be conducted by the school psychologist or another qualified person within the school in order to see what precedes his negative behaviors.  For example, perhaps he is the one being teased and is reacting to his situation.  However, others may be more "stealth" and he is who receives all the blame.  ( I am in no way condoning his behavior, however, he may be reacting vs. instigating.)
 
Also, he may need practice with social situations through group counseling where role playing is used to help children who have difficulties with comprehending social situations or misreading social cues.  When a child does not understand socially what is around him he may react in a negative fashion by misbehaving , having tantrums, crying or being very withdrawn.  Having an opportunity in a safe environment to encounter social situations and problem solve them in a small and accepting group would be helpful, perhaps.  You may wish to ask the school if such a group is possible for your son to join.
 
 
I wish you the best of luck and please let us know about his progress, if you wish.
 
Louise Masin Sattler, NCSP
Nationally Certified School Psychologist
Owner of Signing Families
http://www.SigningFamilies.com