hair pulling

My child has Angelman syndrome and he thinks loud outbursts, noises, etc. are funny.  So, discipline is hard because if we raise our voice, he laughs.  If we talk gently and tell him why his behavior is bad, he doesn't really get it.  He is almost 5 but cognitively about 15 mos.  He is very strong and the worst behavior now is hair pulling, especially our two year old's hair.  It hurts us, so I know it hurts her.  I think he does it partly for the reaction and partly to get us close to hug, sensory issues.  Any suggestions to make him stop?  Also, what do I tell my two year old?  He is obviously not sorry because he is laughing.  Thank you.

[Kevin Kennedy, Ph.D.]

A strictly behavior modification approach is necessary, due to the cognitive impairment involved with AS. Right away you can implement a rigid time out system, placing him immediately in time out whenever any aggressive behavior occurs. In addition, retain or enlist the services of an Applied Behavior Analysis (ABA) specialist to come to your home and observe your son's interactions and design a behavioral plan.