J.B.
YES YES YES! We too have had anger and behavioral issues with our 4 year old son who will be 5 in March. I meant to read it long before and I really wish I had. We took our son to a child psychologist; we've tried all sorts of different diet modifications and disciplinary strategies, but Love and Logic is the FIRST one that we have seen consistent improvement with! I do think a lot has to do with him maturing a little bit. He didn't really go through the "terrible twos" but he DID have the terrible threes and fours. For the past several months though, it has brought so much peace to our home. YES, we still have issues sometime, and sometimes we still lose it (as you can tell from the book -you have to also train yourselves!), but I am in love with the fact that not only is it working behaviorally, but it works to instill personal responsibility and confidence in decision making BEFORE the kid is in high school and college -when it's really too late for the most part without some really hard lessons.
We also have a 2 year old who it's working very well with. We implemented with our 4 year old pretty much by the book. Everything wasn't perfect from the start, but it started making a difference quickly. I have been very specific to spell out expectations for him -i.e. "In the mornings after you're dressed and your teeth are brushed, make sure your socks and shoes are on, the lights are out upstairs and if there's anything you want on the way to school -cereal, waffle, juice, Clif bar -then you need to get it and have it ready to go. Make sure your backpack and jacket are on and ready." This took a few times, but one of our biggest fight inducing, tantrum throwing nightmares has been getting out of the house in the morning -with both kids, work stuff, their school stuff, the fits as we pull out of the driveway because *I* didn't get him a snack, etc. Yes, he refused his jacket a few times and yes he was cold. I put mine on and told him I was glad I had it because it was really cold out there; he said he wouldn't get cold, but after the 2nd time he started meeting me at the bottom of the stairs with not only his jacket but his hat and gloves on! You'll get some looks too -like, "Why doesn't your kid have on a jacket?" -or whatever it is. I just calmly said -twice -when actually asked that he was almost 5, he knows when he's cold, and it was his choice to not wear one today. My favorite is telling either of the boys that they are welcome to continue their fits, screaming, ugly talking or whatnot up in their rooms alone, or they can be nice and continue to stay downstairs and do what they're doing. I'm shocked at how well it works! Good luck!