I think there is some evidence for the benefits of acceleration that comes from an Australian study of gifted students that you may be interested in investigating. (By no means am I gifted, and it's entirely possible that I'm mischaracterizing or misunderstanding the results.) The book is Exceptionally Gifted Children", 2nd edition, by Miraca Gross. An excerpt can be found at [1].
There are some previous HN comments that discuss this including [2], which names Terrence Tao, UCLA math prof, as one of the participants in the study.
Two passages that I think highlight the extremes both in acceleration and outcome are:
“… 17 of the 60 young people were radically accelerated. None has regrets. Indeed, several say they would probably have preferred to accelerate still further or to have started earlier…. The majority entered college between ages 11 and 15. Several won scholarships to attend prestigious universi- ties in Australia or overseas. All have graduated with extremely high grades and, in most cases, university prizes for exemplary achieve- ment. All 17 are characterized by a passionate love of learning and almost all have gone on to obtain their Ph.D.s.”
“The remaining 33 young people were retained, for the duration of their schooling,… Two dropped out of high school and a number have dropped out of university. Several more have had ongoing difficul- ties at university,…”
There are some previous HN comments that discuss this including [2], which names Terrence Tao, UCLA math prof, as one of the participants in the study.
Two passages that I think highlight the extremes both in acceleration and outcome are:
“… 17 of the 60 young people were radically accelerated. None has regrets. Indeed, several say they would probably have preferred to accelerate still further or to have started earlier…. The majority entered college between ages 11 and 15. Several won scholarships to attend prestigious universi- ties in Australia or overseas. All have graduated with extremely high grades and, in most cases, university prizes for exemplary achieve- ment. All 17 are characterized by a passionate love of learning and almost all have gone on to obtain their Ph.D.s.”
“The remaining 33 young people were retained, for the duration of their schooling,… Two dropped out of high school and a number have dropped out of university. Several more have had ongoing difficul- ties at university,…”
[1] https://files.eric.ed.gov/fulltext/EJ746290.pdf
[2] https://news.ycombinator.com/item?id=11510032