I looked at the 5 examples for a bit. Reading the Wikipedia talk pages, I'd tend to agree that the sources removed are representing a fringe idea and that the Wikipedia process has been followed normally. You'd find lots of sources for every fringe idea, but that doesn't mean those sources are good.

But surely there are people who edit things about intelligence and race due to non-scientific reasons like their beliefs, politics or emotions. I think people from both sides of the issue/argument/debate are making such edits, like with every issue.