...ah. Yes, I imagine the parallels would be sort of awkwardly imprecise. Our family structures don't involve any kind of kin-selection instinct.

[Enough so that while she thinks she mostly understands the issue on a theoretical basis, it's not something that has any real immediacy for her personally.]

If it softens it any, it's not as if all rivalries are romantic. Most people have friends they amiably hate without any degree of sexual tension coming into play.