We were PBS only kids (my mom was ubercrunch), though we read a lot of Narnia and the Hobbit type stuff. Lots of swords, arrows, spears, etc. My brother, however, was way into guns. At 18 months old, having a) never seen a real gun (my parents didn't own them) and b) having never been around gun owners, picked a stick up in the yard, pointed it at the sky, and said, "Pew! Bird dead." I think some of this stuff is hard-wired -- like baby animals play fighting.