User blog comment:FirstDrellSpectre/FDS's crazy theories/@comment-30948167-20170713164831

About theories 5, 8, and, 9.

https://www.sciencedaily.com/releases/2002/11/021112075626.htm

http://www.abc.net.au/science/articles/2002/11/12/725131.htm

http://indianapublicmedia.org/amomentofscience/are-tomboys-born-or-made/