*By blatant lying, I mean telling a lie that you can't possibly think the other party actually believes, and you tell the lie, not in order to be believed, but just to gain initiative or aggression in the conversation.
**By physical domineering, I mean things like cajoling him into hugs and then not releasing him, poking him when it makes him uncomfortable, grabbing his clothing to keep him close, things like this.
Older sib, age 14, does these things to younger sib, age 9. Younger sib has a fraternal twin who, while I wouldn't say older sib treats well, also doesn't almost ever receive any of the above treatments from older sib. And they all have another oldest sib (16) who is actively supportive and friendly to all of them.
I am not sure how to say this convincingly if someone were skeptical, but for what it's worth: Older sib does not get this behavior from me.
Do we know (from research I hope, but there can be other ways to know things) whether a kid who habitually does things to his or her siblings can be taught to understand they are doing this, that it matters, that there are other ways to do things, etc?
(I am divorced, with shared 50/50 custody. Ex spouse is aware of these problems to some degree, but we are unfortunately not friendly with each other and very different as parents so we don't have any joint approach.)
I help the younger sib by providing validation and rescue, and by being forthright, in front of younger sib, to older sib, about the inappropriateness of their behavior. I try to help younger sib feel secure in their relationship with me and secure in knowledge that I see what is happening and am responsive to it in a way that helps younger sib feel safe.
But I can't have eyes on both of them every time they are in the same room together. Indeed I'm only their custodial parent half the time, if for no other reason.
And I'm not quite to the point where I feel like it would make any sense to either of them if I literally forbid older sib from interacting with younger sib or something as extreme as that. (I mention this partly to let you know that, to be honest, lately, that's where my mind goes.)
Can a kid doing these things be talked out of it? Incentivized out of it? What do we know about this?
Things I already do:
Speak in a straightforward, clear and truthful way about what I see older sib doing
Speak for younger sib as necessary, saying things like "he said no," or asking younger sib directly "are you enjoying what you two are doing right now?"
Try to help older sib see younger sib's point of view
Try to avoid defensive or closed-minded reactions from older sib, by keeping stakes low for them, by not being punitive and instead being problem-solving oriented. (This is in response to extreme reactions older sib has to the prospect of being embarrassed or of suffering purely punitive consequences. It's tempting to say "be punitive anyway" but my experience with this child is that they do not take away any kind of understanding or lesson from that, but instead dig in and escalate. While there is an obvious power differential in the parent/child relationship, I don't believe in ever letting a conflict become about reinforcing that power, so rather than participate in an arms race, I try to find ways to defuse or do end runs around things that might trigger escalation from the kid.)
Allowing them to see and hear about my own frustration, disappointment, even anger, concerning their behavior, and being truthful to them about how it changes my own behavior towards them
The older sib does see a psychologist and a counselor for other issues, but only very unhappily, not feeling there is any use for these meetings. The meetings serve, to be honest, mostly as a pro forma certification that zoloft is continuing to help the kid with anxiety. While I'm going to be looking for an opportunity to broach this topic with one or both of those practitioners, past family therapy sessions and my own experience with the kid don't give me much of an expectation that it will help. (In the past, when talking about this together with the kid on a therapist's couch, and when the kid talked to that therapist alone, the only response was a sustained refusal to acknowledge any responsibility for their behavior and refusal to try any possible approach towards communicating more forthrightly about them. This was sustained over multiple meetings, and that therapist said to me towards the end that she was out of ideas. And I want to note, because I always fear "what if it's all me, what if my kid is just being normal and I'm being an awful parent in all this?" that the therapist was explicit that it was clear from our conversations that this was not the case at all and that I am genuinely trying to take constructive steps concerning actual problem behaviors.)
Well... anyway... I am seeking serious advice from experienced or informed points of view.