I know, it's one of those easily-mockable TED talks. But hey, just because they're easily-mockable doesn't mean they're worthless. This one is fascinating, even if cognitive ability isn't one of your hobbyhorses (it is one of mine). I even added German subtitles.
The 'Flynn Effect' is named for James Flynn, the man in this video. The Flynn describes the fact that in an absolute sense, humanity as a whole has become smarter every decade of the recent past. In the past 150 or so years, humanity has enjoyed steady increases in cognitive ability. Literacy has become almost-universal, average numbers of years educated has increased, the number of people engaged in cognitively demanding professions has skyrocketed, and the median level of cognitive ability has increased, making it normal and routine for people to think in abstract categories that would be unintelligible to people living in, say, 1890. The effects are concentrated mostly in the global North, of course, but they're spreading everywhere.
Forget just about everything you learned in sociology classes, this is probably the most important change in the human condition since the Renaissance. And most people have no idea it happened.