Group A, those who obtain advanced (e.g., graduate) education and achieve exceptional career success as scientists, professionals or business leaders, and
Group C, another group that end up in less (intellectually) challenging jobs and with much less formal education (often no more than a high school diploma).
On the re-tests of these adults, did Group A outperform Group C relative to their childhood scores? No.
What does this mean? Enrichment is again seen as unlikely to drastically alter cognitive ability. An 1150 SAT kid is not going to become a 1460 or 1600 kid as a result of their college education. Yes, those funny little tests are measuring something real and relatively stable.
These results have been known for many years, thanks to the Terman study of 1,538 gifted individuals (see here and here). Note that overall the "Termites" tended to be very successful in life; we focus on the most and least successful outliers (Groups A and C) to test the effect of enrichment on cognitive ability.
Terman Study, volume 5: ... Perhaps the most direct way of determining whether the higher and lower occupational groups differed in the way they changed from childhood to young adulthood and then to middle age is to compare the average rank order of [each group] ... at these three stages of life. There was no difference in the amount of change in intellectual performance (IQ) to young or middle adulthood or in Concept Mastery score over the decade from early to later middle age. We must conclude that ... there was no tendency for the lower-level group to slip downwards during their careers.
Stanford alumni magazine: ... the 100 most successful and 100 least successful men in the group, defining success as holding jobs that required their intellectual gifts. The successes, predictably, included professors, scientists, doctors and lawyers. The non-successes included electronics technicians, police, carpenters and pool cleaners, plus a smattering of failed lawyers, doctors and academics. But here's the catch: the successes and non-successes barely differed in average IQ. [All Termites had high childhood IQs as a consequence of the selection process.] The big differences turned out to be in confidence, persistence and early parental encouragement.
10,000 hours of practice won't make you a genius, but being good at something might make you more likely to pursue it for 10,000 hours!
The high IQ scores of eminent scientists (measured late in life) were probably not caused by their scientific activities. Rather, their high cognitive ability aided their scientific success. This ability, while necessary for success, is clearly not by itself sufficient.
