So the gender differences he talks about are very obviously coming from this meta-study:

http://sci-hub.cc/10.1111/j.1751-9004.2010.00320.x

He uses a lot of the same terminology as the paper, references big-5 personality traits etc, as well as the same personality dimensions like people-object axis.

The left vs. right stuff is clearly coming from Jonathan Haidt's Moral foundations theory:

https://en.wikipedia.org/wiki/Moral_foundations_theory

The author of the "manifesto/screed" is drawing pretty clearly from good research, but isn't linking to it or discussing it in context