yikes. Well we went through a period of issues with the boys from about 18 months to about 2.5 (yes a year) and our kids were not adopted (I was but that is another story!). Things that helped:
- talking a LOT to DS1 about his feelings and that they are ok (maybe you had sibling issues etc when you were little?)
- helping him verbalize his feelings (you feel mad that DS2 knocked down your castle) by modeling
- we did a sticker system for a while -- 5 stickers gets you something (a small lego set for us) this worked really well -- stickers were given for respecting others (eg not hitting DS2)
- also we needed to "punish" DS2 -- DS1 felt it was REALLY unfair that when DS2 did something wrong there was no consequence, so we put him on the step (for 2 seconds) when he threw or hit etc. this helped DS1 not feel like he had to be the "police man"
- separate them when possible to get a break
I hope it is ok that I responded even though I didn't adopt -- but I can relate to the sib issues.
GOOD LUCK!
/hillary
DS #1 Summer 05
DS #2 Summer 07