Originally Answered: Philosophy?
A basic civilizational change in the West has been noted by Flynn. Namely, 100 years ago, if you were to ask most people what "dog and rabbit" had in common, the answer would be concrete and experiential: "the dog chases the rabbit." This conformed to their experience. Today, the same question to most people gives something more abstract, like "they are mammals."
The Flynn effect is a documentable rise in IQ test scores on a decadal basis. Its cause is the more abstract and connected level of secular, practical education which has moved in western society in the past 100 years.
The Flynn effect is thought by some to be an artifact of a rise in emphasis on abstract connectedness, e.g. knowing that "rabbits and dogs" are "mammals." This promotes a certain test-wise score increase. However, in contradistinction, 100 years ago, literacy levels were higher in e.g. America, grammar and writing skills demonstrably more advanced, and audiences of ordinary folk typically listened and followed complex political debates with much more ease than do audiences today.
There is a well-known science fiction story, "The Marching Morons," which may typifiy this latter "gee, we're more advanced" notion, much as U.S. students think they're excellent at math, but typically score below average among nations: a few geniuses, with lots of mass merchandising, sell cars with fins, loud engines, etc. to the "MM." The "MM" think they're getting hot stuff, but in reality they're going slower. A similar event occurred with SAT scores in the late 1970s or early 1980s, when student SAT scores were going down, down, down, so the SAT people "renormed" them, adding dozens of points to the "new, improved" SAT, so now people think they're doing just about as well as the 1960s group, but in reality, they're scoring perhaps 50-100 points lower, as a group.
"Climb the Highest Mountain," Mark Prophet, has some good insights into how such things happen.