If the grandmother hypothesis is true, then you’re still talking kin selection effect via grandparents, which is very different than group selection. I concede

If the grandmother hypothesis is true, then you’re still talking kin selection effect via grandparents, which is very different than group selection. I concede that kin selection is very possible, but again, as this is an unproven hypothesis at the moment, still a matter of scientific debate, hence not really clear or obvious.