You can also tell a lot about a person by what kind of music they listen to. People who listen to rap speak poorly and often forget to detach the tags from their apparel. Rock fans drive Jettas with at least one sticker from a radio station in the back window. Country fans are gay. Sorry, I just really don't like country.
But metal fans are a different breed. There are more sub-genres in heavy metal that there are actual genres of music. And every one of those sub-genres has its own hardcore following. Here's a few observations (stereotypical generalizations) that I've made about their fans.
Thrash Metal:Examples - Slayer, Testament, Megadeth
People who listen to thrash are mostly alcoholics and/or Native American. They're beer swilling, ugly, angry neanderthals. They know this and are proud of it. All thrash fans can play part of 'Enter Sandman' on the guitar. Even when sober, they will act, sound and smell like a drunk person. Yes, they have owned that shirt since 1989. They will head bang and play air guitar without provocation and usually at inappropriate times and locations such as weddings, court hearings, and during movie previews. Thrash fans do not own pants, only camouflage shorts. They also use the word "faggot" a lot.
Power Metal:Examples - Iced Earth, Manowar, Helloween
Have you ever gotten one of those catalogs full of replica swords and tiny statues of dragons and thought "who the fuck is keeping this place in business?" Power metal fans are. They yearn for the days of yore when knights fought bravely to the death for the hand of the fairest maiden in the land, when dying honorably was all there was there was to live for, a time when words needlessly ended with an e. They like their metal like they like their sex, epic and full of high pitched screams. Like most heavy metal fans they have long hair. But unlike most heavy metal fans it's combed and well cared for.
Screamo:Examples - Thursday, The Used, Alexisonfire
Screamo is going to be the term I use to sum up nearly every sub-genre that ends with "-core". Screamo fans are just emos with inferiority complexes, which is just sad. They are very emotional people with complex feelings that you could never understand, but are deeply offended if referred to as an emo. They have heard of every band you have heard of and they were listening to them before you. But they don't listen to them anymore because now they've become commercialized the true meaning behind the music is lost. They will tell you that they are not homosexual, and they are only fooling themselves.
Hardcore:Examples - Hatebreed, Pro-Pain, Biohazard
People who listen to hardcore are beer swilling, ugly, angry neanderthals. They do not know this and will go into a full on fit of roid rage if called out on it. They are wholly responsible for the rise and continuation of cage fighting events. They do not mosh for fun, they mosh to kill. Hardcore fans do not have necks, but instead have large trapezius muscles that hold their tiny, bald heads on. They own at least 3 Tap Out shirts, you know the ones that make it look like they have a tattoo that says Tap Out across their chests. But they wouldn't get a tattoo like that man, because this body IS A FUCKING TEMPLE.
Black Metal:Examples - Dimmu Borgir, Naglfar, a bunch of other shit I can't pronounce
Black metal is the most unintentionally hilarious genre of metal. Perhaps because the musicians and fans take it so seriously. Black metal fans wear make-up, or more specifically "corpse paint", to concerts, which is just fucking priceless. Some of them will wear it EVERYWHERE. They don't understand that the band members do it because they are putting on a show. Their inability to conform to society's norms (such as not wearing large pentagrams and black studded leather to job interviews) are the reason that you don't see any black metal CEO's. There are 2 kinds of black metal fans, high school drop outs, and high school shooters.
Death Metal:
Examples - Cannibal Corpse, Decapitated, Guttural Secrete
Death metal is largely regarded as the most violent, aggressive, and fastest music on the planet. Listening to it is like watching a horror movie. It's fans, however, are uncharacteristically nice people. Like large, bearded teddy bears. Death metal fans have long, greasy hair and tattoos of graphic murder scenes, disembowelment, or even brutal depictions of rape. They wear shirts that only other death metal fans can read. Every fan of death metal has tried, and failed, to start a successful death metal band, because "successful death metal band" is an oxymoron. They collect horror movies and posters. All death metal fans have taken an "angry face" picture. They also enjoy kittens.