That article makes absoutely no sense. It's not peer reviewed I hope because those numbers just don't lead me to think... anything...
Hmm... Went to college? Check (twice) In a fraternity? Check (President one year) Owned gun(s)? Well duh... Drank my face off, at least weekly? Check Other risky behaviors? Uhh... check (but not the general aggression part. I was more the calm, collected, sardonic-asshole-in-the-corner-making-fun-of-everyone-in-sight type) So yeah, I guess lump me in with the 5.2% in that study I guess.