I might be biased as I do IQ testing/cognitive testing lol, but...

It is important to consider the context of those Peterson IQ comments. He is not making a value judgement. He's not saying that we should value IQ more, or that intelligent people are more moral, or even more useful. He's just debunking the leftist notion that hierarchies in society are purely based on power. Peterson is saying '..sure, somewhat..but that is not at all the whole story', hierarchies in society are largely based on competence, and IQ and Contentiousness have a ton to do with it.

If you understand what IQ measures, and you understand how personality is measured, it makes a great deal of sense why these traits would create such results.