I posted the article, because I found it interesting, but personally, I don't know how any "researcher" could ever truly prove a theory like this. One would have to exhume Bach, Handel, Einstein, Galileo, Isaac Newton, Racmaninoff etc...........to see if their testosterone levels were as high as Jeffrey Daumer's, Ted Bundy's or "The Birdman of Alcatraz" et al.
Yes, it was an interesting article. At the very least the role that testosterone plays needs more study.