"If you don't know 14 Intelligence from 18 Intelligence, you don't know your nff from a hole in the ground." In other words, the limits of knowledge for an entire human society depend on the limits of knowledge of its most intelligent individuals as an optimum. (And believe me, that's being as optimistic as believing in unicorns.)
Let me also clarify that there are no physical laws currently known to form a limit to human intelligence; these are not trees or sprockets, such that they fit neatly in a normative distribution. The ranking and methodology used in modern intelligence testing is just sufficient to rank people in terms of whether they qualify as wage-slaves, middle-managers, or captains of industry; these measurements are not sufficient for an emerging information society. Wicked problems are indeed wicked, but only if you're too much of a chin-drooler to explain to others what the truly important questions are.
Which side of this conflict would like to be on, the losing side, or my side? P;D