No, it was developmental, but AFAIK IQ is rather stable once you reach adulthood.
> and it didn't translate into differences in actual, real-world performance in a way that IQ difference within cohort do
Because it was gradual enough that it would be hard to measure, and because the composition of the Western workforce also evolved over the same period of time, making any comparison between generational cohorts virtually impossible.
No, it was developmental, but AFAIK IQ is rather stable once you reach adulthood.
> and it didn't translate into differences in actual, real-world performance in a way that IQ difference within cohort do
Because it was gradual enough that it would be hard to measure, and because the composition of the Western workforce also evolved over the same period of time, making any comparison between generational cohorts virtually impossible.