Regarding IQ and family ties, that's an answer I've seen put forth elsewhere, I'd say it's the default response. But it could also be explained by a desire for power, nepotism, in-group preference.

Actually someone just posted comprehensive and compelling info for jewish supremacy.

Here's their post

Here's a link to an article and an excerpt:

https://www.unz.com/ishamir/unz-goes-nuclear/

Altogether Jewish kids make up some six per cent of NMS, the highest-performing students’ list. This is a good result, in line with Jewish admissions into meritocratic colleges, but it is four times less than what you would expect judging by their Yale admissions. The Jewish IQ, as Unz found out, is also in line with that of their Gentile peers, and not the fabulous 110-115, as the Jewish newspapers claim. Jews are not all that smart anymore, judging by their score.