Follow the link above to the entire article at Science News Daily. Here's a tidbit:
To find out why this was, the researchers then quizzed 19 gifted students via an online group interview to find out their views on Heavy Metal. These pupils said they did not consider themselves to be ‘Metalheads’ but identified with specific aspects of this youth culture. They spoke specifically about using Heavy Metal for catharsis, literally using the loud and often aggressive music to jump out frustrations and anger.
Ah, head-banging was so cathartic for me. Such memories.