Reddit mentions of Does your Family Make You Smarter?: Nature, Nurture, and Human Autonomy

This is an interesting question, and it's a question that I don't know the answer to.

I'll give you a brief outline though of what I know about the possibility of increasing one's IQ/intelligence (the relationship between IQ and intelligence is itself a complicated subject).

First lets deal with heritability of IQ. The most popular estimate of the heritability of IQ among adults seems to be 0.8 or 80%. This is the estimate I've read from the APA (American Psychological Association) and from reading other sources on IQ.

However a common misconception that many people believe is that an 80% heritability means that 80% of one's IQ is due to their genes, which is wrong. What 80% heritability actually means is that 80% of the variability in IQ within a population can be explained by genetic differences.

Here's a quote from a University website that explains it with an example

http://psych.colorado.edu/~carey/hgss/hgssapplets/heritability/heritability.intro.html

>Heritability and environmentability are population concepts. They tell us nothing about an individual. A heritability of .40 informs us that, on average, about 40% of the individual differences that we observe in, say, shyness may in some way be attributable to genetic individual difference. It does NOT mean that 40% of any person's shyness is due to his/her genes and the other 60% is due to his/her environment.

Next lets deal with the Flynn effect.The Flynn Effect is the observation that for the past few decades, there has been an increase in average IQ by 3 points every 10 years. The relevant question here however is, does this imply that people are getting more intelligent? I personally don't know the answer to that, and I'm not sure if there is a settled answer in the psychometric community. However I do know that Flynn himself has expressed doubt on the view that we are getting more intelligent. I will provide 3 supporting pieces here:

Flynn himself has written in an essay (that I unfortunately have lost and have been unable to find for a few months) that he does not believe that the Flynn Effect is caused by an increase in general intelligence/g/g factor (this is a technical term).

https://en.wikipedia.org/wiki/G_factor_(psychometrics)

There is also empirical evidence from psychometric research that the rise in average IQ (I.E. the Flynn Effect) is correlated negatively with the g-loading of a test. In simple language, this just means that broadly speaking if an IQ subtest relies heavily on general intelligence, there has been a smaller increase in the average than on IQ subtests that don't rely heavily on general intelligence.

http://www.sciencedirect.com/science/article/pii/S0160289613000226

There is also the question of if an average IQ increase of 3 points does not mean we are getting more intelligent, than what does The Flynn Effect mean?

Flynn himself has a great TedTalk answering this question, since as I mentioned before Flynn himself does not believe that we have gotten more intelligent. A TLDR of his explanation is that he thinks The Flynn Effect is due to a huge shift in the way we are taught to think about things and how we view the world. In his words, he believes humans have developed more sophisticated "mental artillery."

https://www.youtube.com/watch?v=9vpqilhW9uI

Lastly if you've been bored by my blathering here and just want a straight forward "Yes" or "no" answer, like I said I don't know the answer. However I do know two experts who each express the opposite answer to the question.

In this book written by an intelligence expert, he claims that little can be done to increase one's IQ however over a person's lifetime their fluid IQ will peak in their mid/late twenties then slowly decline thereafter whereas people's crystallized IQ steadily increases throughout their life

https://www.amazon.com/Intelligence-That-Matters-Stuart-Ritchie-ebook/dp/B00RTY0LPO/

Whereas I have emailed Flynn before about a question related to this question, and he told me that in his book (that I will link below) he explains why he thinks that it is possible to increase one's IQ through hard work.

https://www.amazon.com/Does-your-Family-Make-Smarter/dp/1316604462/