wife lacks patience

No, my wife is so good and nice.

I know this sounds crazy but maybe you could get the book "Family First" by Dr. Phil he has some of the best parenting advice in there. I got my husband to read it and it changed our parenting completly he just has a way of explaining things that make you realize that you are not parenting the best you can. Granted there were a few things that we just said that wont work for us. My other suggestion would be distraction when she starts to get frustrated grab the boy up and say I think he needs to have a Daddy talk then take him to a seperate room until she calms down. My guess would that this is a culture difference in raising children, but I am sure it can be worked out.

Tell her that the next time she hurts the child you will report her to family services, and then do so. You must get that poor baby away from this abusive woman. leave her, take the baby, and file for custody. Or, tell her that the next time she hurts the baby, for no reason, you will do the same to her. let her see how much it hurts to be pinched! She doesn't deserve children!

I think the best way to do it is you talk to her when she's at her best mood. that way you guys won't end up fighting. tell her what you want to tell her in a way that she won't feel that she's not being a good mother to your child. I hope this helps. this is all I can offer since I still don't have my own family.