> I'm assuming that if I pick random PhDs and hot dog vendors, I will get a higher average IQ from my random PhDs. Are my PhDs strictly greater in IQ than my hot dog sellers? Maybe, maybe not. But will, say, 99% of my PhDs have a higher IQ? I'd bet on that number or something like it.
Are PhDs dominated by technical types? Can you have PhD in arts or post modern philosophy? Does that require high IQ?
> No, they were not. There were a few geniuses back then, the ones we still read and write books about. All few tens of thousands of them out of billions. But the average was vastly below the modern-day.
Not everyone could write a book back then. Not every book from back then survived. You can't tell how many ancient Ramanujans left no trace. Ingenious concepts of later ages often cropped up multiple times centuries earlier only to be dismissed and forgotten.
That said you are spot on environmental factors. Here http://www.ted.com/talks/esther_duflo_social_experiments_to_... it is said that thing as simple as deworming might increase very significantly children spend on learning and training their intellectual capacities.
> Can you have PhD in arts or post modern philosophy? Does that require high IQ?
Yes, and yes for the latter. Philosophy is my own field, and while I would be much more comfortable making this assertion of analytic philosophers, post-modern (I'll assume you really mean 'continental') philosophers are still very smart people.
Since you aren't doing any research, I will do just a little, and point out that philosophy PhDs tend to have been philosophy majors, and philosophy majors tend to have extremely high GRE scores, and the GRE is extremely correlated with IQ; philosophy majors are #1 and beat every other major when it comes to the Verbal and Analytic Writing sections - surely not the work of people of average intelligence - and rank 15th out of 50 in math scores (ahead of majors such as biology, accounting, architecture and others; being beaten by various engineering, physics/astronomy, and math majors): http://www.ncsu.edu/chass/philo/GRE%20Scores%20by%20Intended...
> Not every book from back then survived.
Yes, but many catalogues (the Suda eg.) and quotes have survived. The survival rate and biases introduced by history can, and have been, estimated. (The latest one I heard about used statistics about the survival of works of the Venerable Bede, but I can't find the citation in a quick google.) The bias is not orders of magnitude, though it hits some authors badly (Sophocles's prize-winners, eg.) as one would expect from a random process.
Are PhDs dominated by technical types? Can you have PhD in arts or post modern philosophy? Does that require high IQ?
> No, they were not. There were a few geniuses back then, the ones we still read and write books about. All few tens of thousands of them out of billions. But the average was vastly below the modern-day.
Not everyone could write a book back then. Not every book from back then survived. You can't tell how many ancient Ramanujans left no trace. Ingenious concepts of later ages often cropped up multiple times centuries earlier only to be dismissed and forgotten.
That said you are spot on environmental factors. Here http://www.ted.com/talks/esther_duflo_social_experiments_to_... it is said that thing as simple as deworming might increase very significantly children spend on learning and training their intellectual capacities.