Of course, but "useful" is different from "increases reproductive fitness", and the basic assumption is that the selective pressure of intelligence came from competition inside the species. It is sort of difficult for me to imagine what kind of competition can happen between ancestral females to increase reproductive fitness (and not simply to have a better life, these two are different things). Let's assume for now it is not for higher quantity of children, nor for higher quality sperm thus the genetic quality of children (it does not really require much of a competition, it is cheap), what else is left? Largely the upbringing and life of those children. Am I on the right track there that it is more about what happens to the children once they are born? Are the get resources invested by the genetic father, by the tribe, by the chieftain, by the queen, by whoever, what status they get and so on? As this sounds vaguely possible for I just don't know to visualize it. (Sort of Cersei Lannister situation, push children into high status positions?)