E.,
Your educational background and mine sound very similar. Additionally, I too am the mother of three - 5, 22 months, and 4 weeks. I, also like you, do not believe in spanking, which has worked for me so far. However, the 22 month old is extremely strong-willed and has a temper. Time-outs are very time-consuming and require a lot of energy on our part. You probably know all of the techniques that I do given your education. Since he has the ability to behave in school, these are behaviors he can control.
I have 3 thoughts:
1. When did these behaviors begin? How has he adjusted to having a younger sibling? Do you think any of this is linked to a resentment towards you for having a baby and/or jealousy of the baby?
2. I don't know what your temperament is like but you probably know that you can have all of the techniques but if you don't have the attitude with them then they are no good. My sister's 3 year old son is a very demanding, difficult child. Much of what you describe sounds like him. He is great for me, however, and does well in preschool. He saves these behaviors only for his mother. I taught her several things to do with him, but nothing worked until I brought it to her attention that she is too passive. Her methods worked for her other two children but he was too strong-willed and smart. When she stopped showing and expressing that he was wearing her down and began interacting with him in a more assertive, confident manner, he did improve.
3. Have you ever tried the contract system? It worked really well for my 5 yr old when she was going through a difficult phase. I use it for my child clients and help the foster parents of my clients set one up at home. I have seen it work well for children who have many behavioral difficulties. In case you are not familiar:
Have a blank at the top of the page for the child to write his/her name (or you write it). Read to the child what you wrote/typed on the top of the page - something like: "I am a great child. I want to behave for my parents. I agree that I will do the things on this page if I do not behave." It should read how he will understand - just make it appropriate for his age and maturity.
I use excel to make a chart but you can write it however you want. The point is to identify specific behaviors that are problematic then have a consequential chore for each behavior. Given his age, I would do two or three at most. For example, if you are having a problem with him throwing things when he is angry. Talk to him and show him what he can do when he is angry to appropriately express himself (I know, you are probably laughing at the thought of him appropriately doing anything!) Write/type "Thowing things when I'm angry" under the title, "Behaviors to Improve". Next to it, under the titlem "Consequences", will be a chore that is age-appropriate. Try to pick something that he would not like doing. For example, my 5 yr old loves to muck our horse stalls so I can't use that as a consequence like I do for my clients. If you think about it, you can probably think of some type of work that he does not like doing.
The point of this system is that it is a contract that they sign and agree to. You are not the bad person if they must carry out their consequence. Yes, it takes some time, but it works and I have seen it work with 2 yr olds. It is great for teaching self-discipline, self-control, consequences for actions, responsibility, and confidence. Another example, we had a teenage relative of ours live with us for 3 months last year. He came from a home where there were no demands on him so he could do whatever he wanted, but at the same time, he was abused. He was very difficult when I told him to brush his teeth or bathe every night. In an effort to give him some kind of independence but enforce what was expected of him, I created his own contract that hung on the fridge. If he did not brush his teeth on his own, without me reminding him to do it, he had to scrub the tiolets upstairs. The first two days I asked him if he had brushed his teeth and reminded him of the chart before he cleaned the tiolets. AFter that, I never said a word. I would hear him curse under his breath when he realized he had not brushed them then I saw him clean the tiolets. This was him agreement - I never said or did anything at this point. This took one week then he never forgot to brush his teeth again.
IF the child refuses to abide by what has already been discussed and agreed upon, the child does nothing, loses all privaledges until he/she complies with the contract. It takes patience at first but it will work.
I hope this helps! Good luck. I hope you find an answer soon so you can be the mom you enjoy being.