Intelligence (n.) wants an outlet; denied politics and creative work, people pour it into kinship charts, language games — or batting averages.
Intelligence (n.) may turn out to be a biological error: the one species clever enough for civilization may spend its 100,000 years destroying itself.
Intelligence (n.) has not been favored by evolution: by the measure of survival, beetles and bacteria beat us easily.
Intelligence (n.) of the higher kind may be on a suicidal course, with every other species reduced to collateral damage along the way.
Intelligence (n.) barely matters to learning one's mother tongue: the dull and the brilliant, raised in very different homes, end up with nearly the same grammar.