Q&A: Older child consumed with fighting with younger child

Angie writes:

"My 10 and 8 year old girls keep having the same argument. The 10 year old believes with her whole heart that the 8 year old should do everything she says. The 8 year old goes out of her way to defy the 10 year old. It often comes to blows, and it's driving me nuts. The 10 year old's behavior is bordering on bullying: threats, blackmail, etc. and the fights often end with aggression on her part. Please help before they spend their entire summer grounded to their rooms."

I asked why the older daughter thought her younger sister should do what she said, and that that false belief was the source of the trouble. Angie replied:

"Because she's older and bigger. Logic, which usually works on her, does not seem to get through to her. She is very competitive but more than anything can not stand to lose to her little sister. And that seems to have translated to: little sister not listening equals losing. She has anxiety which has flared severely this spring and I am actually seeing some OCD behavior now too. I think this is wrapped up in all of that, that if her little sister "wins" it makes her feel anxious, like shes not good enough. (We have a counseling appt scheduled.).

I'm reaching out for advice because when tempers flare I think I'm making things worse. I just can't seem to find the right tactic."

I'm not sure there is a right tactic here, because the situation isn't based on a clear path of logic.

Your older daughter is feeling tons of emotions AND behaving based on a something that isn't true for your family. (In some systems a younger sibling would have to obey an older sibling, but that isn't the case in most cultures here in the US, and is antithetical to the way most of us raise our children.) Since she isn't processing that her belief is not correct for the situation, you can't really approach this in a way that uses logic.

My first priority would be to protect your younger daughter from her sister's aggressive behavior. While she may be exacerbating it, it certainly isn't her fault that her sister is having this problem, and she shouldn't be forced to violate your family system and her place in it just to avoid aggression against her. So she needs to be protected from the aggression.

The second priority I'm basing on the fact that you have a counseling appointment, so I'm assuming someone who knows way more than I do about why your daughter is having this problem and what you can do about it will deal with that. (I know NOTHING about why this is happening or what you can do to fix it, and couldn't give any recommendations even if I did.) The second priority is to protect your older daughter from her own aggression. Whatever you can do to calm her down you should do. You clearly can't talk her out of her belief that her sister should do what she wants her to, so trying to reason with her isn't going to calm her down. Music, a massage, Rescue Remedy, a warm glass of milk, crawling across the living room floor a few times (because of the arm and leg coordination that happens in crawling that can help clear your head). Whatever will separate her from the aggression and get her some relief.

I'm really hoping the counselor can shed some light on why she's holding onto and preoccupied with this belief right now, and can help you help her to get free of it.

Has anyone been through something like this? Was there anything you did that helped or didn't help? Any ideas what's causing it to happen?