The 2 top criterias for a man to choose a female partner are
1: does she fuck well?
2: does she cook well?
That's all. The rest, intelligence, humor etc, are just possibles bonus assets who must not enter in conflict with the 2 top criterias. The thing is that the more educated they are, the more "intelligents" women seem to forget that if they can't bring good sex and good food to their men, they make his life miserable and can't save that with a master degree or a nobel price.
Education is fine when it's on the field of dance, art, litterature, singing, dramtic art some philosophy, for example, theses things which can help a woman to develop her beauty and sensuality, to have a beautiful spirit and a beautiful mind. Elsewhere, a woman who has an IQ of 145, has a master degree in finance, work 50 hours per week, don't want kids or do the laundry, can't cook and can't dance and have no sensuality is not attractive.
The intelligents women who keep in mind that men have no problem with their intelligence as long as they are sensual, naturally caring, do the laundry, value greatly the opinion of thier man and are ready to put their career in second place to raise the kids have nor particular problem to find a man.
But the thing is that "intelligents" women are often not like this, so men prefer less inteligents women. That's all. And that has nothing to do with "insecurity". The "insecurity" bullshit is just the rationalization of all theses "intelligents" women who are ugly, have no sensuality, can't dance and can't date.
Intelligence doesn't make insecure. An ugly bookworm with a IQ of 145 who has not physical assets or emotional intelligence doesn' make anybody insecure.