I'm curious if more recent data would disagree at all with this. I agree the whole 1950s as some sort of turning point (or near to) is likely false based on the meta-analysis you linked but I find the idea that this started taking off in the 21st century to be a plausible hypothesis.
Another thing to consider is that though actual correlation with success may not have changed, the cultural attitudes surrounding it may still have. My high school years were in the late 2000s, and although my elementary/middle school years lent credence to the "nerds get beat up by jocks" cultural cliche, my experience (and that of many other nerds) in high school was not anything like what I expected. Not only that, but the nerd/jock divide was blurred to the point of being essentially non-existent. A lot of the people on our championship-winning football team were at the top of our class, and definitely not by virtue of the teachers just passing them because of pressure from on high. This doesn't seem to be such an uncommon experience for my generation.
On a more subjective note, I actually find the attitude aspect to be the more detestable one. One can defend intelligence being correlated with success from a lot of at least not totally evil viewpoints: it makes sense to have more intellectually skilled people in jobs requiring more intellectual skill, intelligence requires some level of cultivation so there should be incentives to do so, etc. But while the social carrot has some arguments that start from acceptable terminal values, the social stick does not. I would be very surprised to learn that chastising people for being stupid across the board made them (or anyone else) smarter. The only motivation I can only see for it is purely egotistical.
Another thing to consider is that though actual correlation with success may not have changed, the cultural attitudes surrounding it may still have. My high school years were in the late 2000s, and although my elementary/middle school years lent credence to the "nerds get beat up by jocks" cultural cliche, my experience (and that of many other nerds) in high school was not anything like what I expected. Not only that, but the nerd/jock divide was blurred to the point of being essentially non-existent. A lot of the people on our championship-winning football team were at the top of our class, and definitely not by virtue of the teachers just passing them because of pressure from on high. This doesn't seem to be such an uncommon experience for my generation.
On a more subjective note, I actually find the attitude aspect to be the more detestable one. One can defend intelligence being correlated with success from a lot of at least not totally evil viewpoints: it makes sense to have more intellectually skilled people in jobs requiring more intellectual skill, intelligence requires some level of cultivation so there should be incentives to do so, etc. But while the social carrot has some arguments that start from acceptable terminal values, the social stick does not. I would be very surprised to learn that chastising people for being stupid across the board made them (or anyone else) smarter. The only motivation I can only see for it is purely egotistical.