Kantor on 31 January 2013
On average? Not at all.
You have to remember that, until about a century ago, 90% of the population was an uneducated underclass, and a significant proportion of people couldn't read or write.
That is no longer the case. Pretty much everyone has at least a certain base level of intelligence, and is certainly more knowledgeable than the average person used to be, thanks largely to the invention of the internet.
It may well be the case that the "ruling class" as such is getting stupider as it moves from an intellectual elite to a democratic popularity contest, but that's something else entirely.
(Former) Lead Moderator and (Eternal) VGC Detective 
