You're irritated because I gave you an output of the broad-sense heritability statistic that conflicts with your intuitive understanding of what "heritability" means. Now you understand how people feel when commenters randomly throw around the term "heritability" with respect to cognitive ability.

This is a "not even wrong" situation. Is cognitive ability significantly genetically determined? Maybe, maybe not. A broad heritability statistic from a twin study isn't going to resolve the question.

Here's a good link for you:

http://bactra.org/weblog/520.html

I promise, the author has studied and thought more carefully about the question than we have.

Fair warning: you would not be happier if I cited a molecular geneticist on this subject. Your argument gets even harder to sustain once you bring GWAS into the picture.

I'm not at all irritated besides the fact that you're relying on examples that simply are incorrect, and instead of responding to this issue in any way you're linking to walls of text from somebody who (1) has made plainly false statements on the topic already and (2) has literally 0 qualification in the field whatsoever.

It'd be akin to arguing to somebody who wants to claim the Moon landing was faked, and after the rather straight forward rebuttal of their argument links to some blog in the tens of thousands of words from some statistician they claim is "very smart." It's silly.