both parents with PhD degrees? How about only one parent with a PhD?

I wonder if the area of study is important. In DD's class in NYC, where 99th percentile was a cutoff on the OLSAT, there were 3 pairs of MDs, 4 pairs of PhD (all STEM - from chem to astrophysics), a smattering of one parent MDs, partner varied. I would say that at least half the class had STEM based parents from a group of 20.

Considering we got many of our PhD's from Columbia, there wasn't representation from non stem PhDs

HighIQ - while it is said that IQ of family members is closely related, the age-old question of Nature-or-Nurture comes into play. I'm not finding a definitive study.

But a few quick web searches show several Q & A:

1) Average IQ of PhD
https://brainsize.wordpress.com/2014/07/12/the-iqs-of-academic-elites/
"PhD... around 125"

2) IQ and years of education
https://brainsize.wordpress.com/2014/06/02/iq-years-of-education/
"... staying in school also affects IQ. On page 615 of The Bell Curve by Herrnstein and Murray, they find that even after controlling for earlier IQ, each year of education independently adds 1.65 IQ points to later IQ. However one should not conclude that school makes you smarter. According to Arthur Jensen, the preponderance of evidence suggests that general intelligence is a physiological variable that can not being improved by psychological or cultural influences. However IQ tests are not perfect measures of intelligence, so getting a lot of education allows you to artificially boost your score. School teaches you to concentrate on complex mental tasks and gives you the confidence to try your best. It also exposes you to the general knowledge and vocabulary that many IQ tests probe."

3) CBS - 12 reasons not to get a PhD
https://www.cbsnews.com/news/12-reasons-not-to-get-a-phd/
"The average student takes 8.2 years to slog through a PhD program and is 33 years old before earning that top diploma."
NOTE - It is possible that a dedication to earning one's PhD *may* come at the expense of nurturing the IQ, aptitude, and abilities of one's offspring.

4) Modern IQ ranges for various occupations
https://www.iqcomparisonsite.com/Occupations.aspx

5) Average IQ by State
https://worldpopulationreview.com/state-rankings/average-iq-by-state


Obtaining a PhD is a function of both intelligence and opportunity.

Interestingly, it has been reported that the optimal IQ is NOT necessarily the highest IQ, but is the range of about 120-125 or so... which happens to match at least one assessment of the probable average IQ of persons who've obtained a PhD.
https://www.inc.com/jt-odonnell/science-says-120-is-the-optimal-iq-to-be-considere.html

Another article responds that the ideal IQ is "... The one you have. Now quit obsessing and get to work. I did psychometric testing for 20 years and here's my take on assuring personal development..."
Another answer to the question of ideal IQ reminds us that IQ is a "single number that really means nothing outside of the context."
https://www.quora.com/In-your-opinion-what-is-the-ideal-IQ

Hi Yanaz - it may be best to create a new post with your question, in the Identification, Testing, and Assessment forum , rather than veering off topic here in the GT Research forum and essentially hijacking HighIQ's thread.