They did a followup study to the 1959 study that they finally published in 1995:
THE GIFTED GROUP IN LATER MATURITY [Genetic Studies of Genius #6]
All of the original authors were long dead but the study continued through with the last questionaire given in 1986.
all of the subjects were gifted students in the 1920s. They froze the entrance pool in 1928, having gathered about 1400 or so students, an almost equal ratio of boys and girls, and they were able to get some rural farmhands who were identified as gifted but did not attend regular schools as well.
I’m reading it now. It’s exciting to me because I was fascinated by gifted-ness as a teenager in the 1980s and here I get to find out “what happened” to this group of kids, who I’d read about their middle-aged selves via statistics, in their later years (1972-1986 – the last study at least 1/2 responded to the study, in their 70s – a bunch died in WW2 of course]