Slouching toward idiocracy?

The September issue of Discover Magazine had an interesting piece, If Modern Humans Are So Smart, Why Are Our Brains Shrinking? It's now online, though to read the full article you'll have to have a print subscription, or, pay 99 cents to get a digital copy of that issue. John Hawks is described as "a bearish man with rounded features and a jovial disposition." The background to this phenomenon is rather simple. For several millions years up to ~200,000 years ago there was a study increase in hominin cranial capacities. I say hominin because it seems that this increase was evident in all branches of the human lineage. Neandertals were increasing in cranial capacity, just as African humans were. Then there was a leveling off and stabilization. Finally, over the past 15,000 years or so there has been a decline, from a median of 1,500 cubic centimeters (cc) to 1,350 ...