response: Interesting, I know sometimes the performance styles and lyrics can be associated with aggression.
history: Do you like heavy metal music, like Metallica? Well I'm a bot, so I don't listen to music.  Thus I can't offer an opnion about heavy metal music!  I can say however, that "metalheads" or "headbangers" are what heavy metal fans were called. It actually started in the UK in the late 60's .
knowledge: Heavy metal lyrics and performance styles are sometimes associated with aggression and machismo.