I think they can be brats regardless LOL. I'm dealing with a very willful 2 year old at the moment.. but to be honest, I think having a little sister is teaching him that the world doesn't revolve around him, so while his behaviour may be in response to that, I think it's a good thing for him to learn Who knows what he would have been like if it was just him and he had everything to himself. possibly worse? hehe.