My toddler hits himself in the head when he’s upset

We recently moved and are staying with relatives while we are waiting for our new home to be ready. My 1 1/2 year old son started getting mad at his 2 year old cousin. She takes his toys away, he takes her toys away, they get mad at each other. Normal toddler stuff.I do my best to remind them not to take other peoples toys, and to head off any fights I can see brewing. His cousin has caught on and waits until I’m not looking before snatching something out of his hands. Then he gets mad, screams, and he hits her. I can usually catch him before he hits her because he does this dramatic wind up before the hit, so I have time to intervene. I tell him to use his gentle hands, and I redirect to a different toy. When it gets bad enough that he can’t be redirected I take him downstairs so he can get a break from his cousin. She has never hit him back, but she has pulled him away from things.Anyway, I guess I have foiled his hitting enough times that he’s realized it’s not working out, because now he’s started hitting himself in the head as hard as he can when she takes his toys or waves one of her toys in his face. I remind him to use his gentle hands and I do the redirecting, and I’m trying to reduce the time they spend together because I can see he’s not handling it well. He’s also started hitting himself sometimes when we put him in his car seat, and when he breaks something and feels frustrated.I’m really concerned about this behavior. Will he grow out of it or do I need to be handling this differently? via /r/Parenting https://ift.tt/2FiBX8f