I would say that intelligence presupposes that a definitive definition of this term is hardly possible. You can only approach this term, but you cannot capture it in time and space. Because it is constantly changing, as are all definitions and inventions that are subject to time flow and change.
That's true. I doubt that there is one genome responsible for intelligence and that we will ever have an sharp, acute tool to measure it. It's always mixed up with gained experience and conditions of measurement.