I never said anything like that. My comments have addressed nothing except your claim that linguistic skills are irrelevant in IQ tests, a claim which you've clearly based on nothing.

> This is total nonsense. We don’t know. Maybe there is...

No one said that this is the cause. Someone proposed it as a potential reason. Someone else proposed that if so, the language barrier might be the issue. These are just hypotheses. They might be right. They might be wrong. They might be contributing along with many factors. The fact that "we don't know" doesn't mean it's unreasonable to discuss, though.

> Do you understand what “we don’t know” means?

You should ease up on the condescension toward others. You're clearly not even reading comments at this point. You're just ranting and your arrogance is unwarranted. I don't know why you're so upset that someone would suggest that immigration might impact a nation's measured IQ, but if you can't engage civilly, maybe you shouldn't engage.

(By the way, it did not escape my attention that you again failed to provide any sources that back up your claims about IQ tests. You seem to demand a much higher standard of evidence from others than you demand of yourself.)