No one intends to be an asshole, but everyone has their turn. This behavior is caused by fear. Either fear that the person will be found lacking or someone will take something from them.
When confronted with a partners asshole behavior, don’t match it. Watch it and wonder what they are afraid of happening. To diffuse the situation ask, “are you ok? This isn’t like you,” even if it is. If this behavior is the norm, then suggest counseling! If they are hitting – call 911!