Is there a cat psychologist in the house?

Our cat Cincy hasd kittens and we kept one, a male, Earl, who is now a year old and has suddenly started attacking his mother every times her sees her. I can't even let them in the house together. They don't just get into skirmishes over food, he will actually go room to room seraching for her until he finds her and then attack. I was sleeping peacefully at 6am when Ed let Earl in. Cincy was sleeping above my pillow. Carolyn and I hid under the covers and finally Ed came in from the kitchen. Earl chased Cincy under the dresser and Ed was on the floor reaching under there and wacking them with his mocassin, trying to break it up.

So I called the Vet today to ask for advice. They said getting Earl fixed might help, but they couldn't promise. Plus it takes like a month for all of the hormones to leave his system. I'm doughtful as well- don't males usually act this way towards other males. Cincy is half his size and doesn't put up any resistance. Also, he tolerated the little barn kitten we were nursing back to health. So why does he hate his mother?