With the advance of science we now have many more intelligent specialists who have decomposed the world into contending and non-coherent fields and subfields. Since the problems we face inevitably overlap field boundaries, our best attempts to deal with the problems crash against this incoherence, and appear stupid. Our less-than-best attempts miss the incoherence by muddling fields together, and will appear to be stupider. Our worst attempts happen when specialists proclaim their local expertise as a general solution to our problems, and are stupidest of all.
We are stupider now due to the particular way we are smart.