Everything you say seems straightforwardly correct or a logical guess. I’d add:
I expect identical twin sisters do feel closer to their nieces than non-identical sisters feel to their nieces. There would probably be a higher degree of discovering that this person just happens to have traits like your own.
Even from a fully logical “optimize my inclusive genetic fitness” perspective, there is value, all else being equal, in most parent-child relationships that isn’t in most aunt-niece relationships. Because you raised this child, she probably trusts you, you know her strengths and weaknesses and where she needs help, etc.; you have a comparative advantage at helping your daughter vs helping your niece. (I speak of good parental relationships; of course, there are some where the parent has a comparative disadvantage. Also, if you know your child is a no-good criminal or something, and you know nothing about your identical sister’s child, then the latter may be a better bet for investing your resources; hence my saying “all else being equal”.)
Unless the identical twin sisters marry identical brother twins, the preferential love for their own husband would distinguish their feelings for their own children
Everything you say seems straightforwardly correct or a logical guess. I’d add:
I expect identical twin sisters do feel closer to their nieces than non-identical sisters feel to their nieces. There would probably be a higher degree of discovering that this person just happens to have traits like your own.
Even from a fully logical “optimize my inclusive genetic fitness” perspective, there is value, all else being equal, in most parent-child relationships that isn’t in most aunt-niece relationships. Because you raised this child, she probably trusts you, you know her strengths and weaknesses and where she needs help, etc.; you have a comparative advantage at helping your daughter vs helping your niece. (I speak of good parental relationships; of course, there are some where the parent has a comparative disadvantage. Also, if you know your child is a no-good criminal or something, and you know nothing about your identical sister’s child, then the latter may be a better bet for investing your resources; hence my saying “all else being equal”.)
Unless the identical twin sisters marry identical brother twins, the preferential love for their own husband would distinguish their feelings for their own children