[cubefox]

IQ is highly heritable, so I don't think there is any environmental factor that has this big an impact, except in extreme cases like severe malnutrition. Also note that IQ increases with age roughly into early adulthood independently of environment, so the IQ of a 14 year old increasing is a perfectly normal part of the heritable parts of development.

[tptacek]

What's "highly"? It's likely somewhere between 15%-50% --- weak-to-medium, if you read it as a correlation coefficient.

[cubefox]

IQ is about as heritable as body height.

> The results show that the heritability of IQ reaches an asymptote at about 0.80 at 18–20 years of age and continuing at that level well into adulthood.

https://www.cambridge.org/core/journals/twin-research-and-hu...

[tptacek]

2013 is the phlogiston era of this science. Even the hereditarians hedge on the 0.80 claim now.

[cubefox]

Source?

[tptacek]

Alex Strudwick Young.

[cubefox]

Link?

[atwrk]

Obviously scientists have thought about that and therefore administer age-adjusted IQ tests for different cohorts, precisely with the aim of IQ staying constant during aging of an individual. And yet here we are.

You really don't need a censorship conspiracy to explain these things. I'd recommend you try to challenge your assumptions about IQ and heritability by downloading a few textbooks about the topics. Many many papers are freely available, and the textbooks are let's say easy to find. You could try textbooks about a more accessible area like developmental psychology as it is more easily accessible and still covers these topics quite well.

[cubefox]

The problem with the "I'm right, you are wrong, educate yourself" reply is that, because of the taboo, different books will say vastly different things about this topic. So you have to decide which books are the "good" ones and which are the "bad" ones.