mine, mine, MINE!

[jackson'smama]

i am sick and tired of my 5.5 yo ds's attitude toward his younger brother (almost 3). he believes EVERYTHING belongs to him and will aggressively defend that belief multiple times a day. anything the younger has, the older wants to rip it out of his hand. if i intervene or, anticipating it, say something about it, he'll say something like "i'm just gonna hit him". and he means it.
the aggression is driving me insane and i don't know how to stop it.
it's also become an issue of 'who has more', 'who sits in THAT seat', 'who gets THAT blanket', 'who goes FIRST', etc.... i don't know where this has come from because i don't see how we have EVER displayed favoritism or promoted this kind of rivalry in any way (other than having a second child?!?!).
when in public, they don't generally act this way (like at our coop preschool or at the park or something). and there are times when he can be so loving and generous (i made you a lego car brother). other times, he WANTS to make the younger one something or set up a train track for him, whatever, and younger wants to do it himself which sets off another argument because he thinks he's doing something great that's not being well-received.
one-on-one time with me and daddy is a regular staple. that doesn't help.
any ideas? i'm about to lose my mind.

[AllisonR]

I've got a 5.5 yo DS and a 3 yo DD, and I think a HUGE amount of it is 5.5 yo development. My kids get along 95% of the time - no kidding. However, in the last 4 months, DS has totally developed an attitude: "I have to go FIRST", "I have to have the blue one first", "I am the gold medal winner..." What works for him is consequences. This morning at breakfast DD wanted the yellow bowl, so of course DS wanted it. Well, so I took it away and everyone got brown bowls.

Actual taking of items is not allowed. If DD has something and he takes it, then it goes right back to DD and he can whine and complain all he wants. That's the consequence for taking. If DS always wants to go first, then I insist on taking turns. I get involved for the 1st set of turns, then they are pretty goof about taking care of it themselves.

I encourage negotiating, and this often works, though if it gets too lopsided I intervene (for example, if DS wants to trade a broken piece of trash for the newest item, then I explain a fair trade. This has worked really well and both now trade quite well.)

Luckily this has been a short phase. I can see DS moving on now, accepting that he will not always win, be first....