The recent news of a sharp rise in autism rates - 1 in 88 children, and 1 in 54 boys, are now said to be on the autism spectrum - has led to widespread fear and concern about a fast-growing epidemic. But many of the new cases are high-functioning kids with high IQs. And society might, in fact, be ill-served by giving all of those children a label as broad and debilitating as “autism.’’ Keeping definitions strict might reduce panic, ease the burden on schools, and ensure that the worst-afflicted kids get the help they need.