Do you wanna be in my gang?" sang Gary Glitter way back in the 1970s, when glam rock was big and teen tribes seemed to be a fixed constellation of hippies, teds and rockers and, as the decade wore on, punks, rude boys and girls, rastas, disco divas and New Romantics... Of course, some did want to be in Gazza's gang. Others thought he was a great big nonce. But who was right?
Being part of a gang has got more complicated over the years, and become ever more integral to being a teenager. Recent research for the Home Office by polling company Dubit identified 10 teen tribes, but my own research indicates that these may already be outdated.
The average secondary classroom is probably home to individuals from many teen species. Teachers can view this with sang-froid or dismay, but experts say a need to belong and yet assert individuality is key to adolescence - as is, of course, keeping ahead of any adults who may think they are in on the game.
Dr Peter Marsh, director of the Social Issues Research Centre and co-author of last year's FRANK report for the Home Office, says: "Like their tribal ancestors, teenagers today learn to understand who they are by defining themselves through social bonds and affiliations with a peer group.
"As they make the hormone-laden journey from child to adult, they forge a personal identity by first creating a social identity.
"Music tastes and appearance are the obvious ways to define oneself, but the ways in which young people talk about themselves to their peers also help them to create a sense of self. To be an individual, we first need to be one of the lads or lasses."
Belonging to a gang offers security, companionship, guidance on what clothes to wear and what music to listen to, and confidence in attempts to forge relationships with prospective romantic partners.
The need to belong is strongest during the early teen years. After Year 11, as teachers have often remarked, young people seem to become much more comfortable in their own skins.
There may be good neurological reasons for all this, as Professor Robert McGivern's research at San Diego university has found. At puberty, children's ability to read other people's emotions declines sharply as the prefrontal cortex, which controls social interaction, is dramatically remodelled.
Indeed, it is all "me me me" for the typical 15-year old, deep in swirling internal change, who needs strong signals to tell him or her who the external "you" might be.
This process is chronicled in Barbara Strauchs' book Why are Teenagers so Weird? She describes the long haul towards regaining earlier competence, and hence less need to impress by external means, which bears fruit only by the age of 18. It is a transformation that Jay Giedd of the US National Institute of Mental Health calls "brain sculpting".
Teenagers are highly susceptible to the negative marketing messages pumped out by celebrity culture: being fat, having unwanted body or facial hair (either sex), wearing "uncool" clothes. These could all be "brass" (horrible) or "butters" (ugly).
In an argot derived from Jamaican street patois, hip-hop records, Cockney slang - all of them heavily laced with once-taboo four-letter words - judgements on age-mates are very quickly formed and delivered (see glossary, below right).
Partly as a matter of survival, partly to avoid fights, and partly to affirm superiority (and thus invite fights), classifying your peers is a constant preoccupation of teenagers. And if you enjoy an activity, be it skateboarding or computer games, you are inevitably drawn to peers who share your tastes.
Above all, says Dr Marsh, it is a "presentation tactic" characterised by "talking up" - be it drug use, involvement in crime or sexual activity.
Don't believe everything your teenage friends tell you, as you can be sure they don't.
The FRANK report found that 17 per cent of 11 to 13-year-olds, 21 per cent of 14 to 16-year-olds, and 22 per cent of over-16s think that their friends pretend to have taken drugs when actually they have not.
According to the Dubit sample, the most self-aware and image-conscious teen group is the Gangstas, who are characterised by their love of hip-hop stars such as Eminem, 50 Cent and The Game, high-end sportswear brands and "bling".
They are most likely to say that their taste in music influences their personal appearance. They are also the most likely to want to "talk up" their drugs misuse - more than a third of them - compared with less than a quarter of 11 to 18-year-olds as a whole, and less than 10 per cent of Academics and Geeks.
There is geographical variation, too. Most Indies, Moshers, Sporties, Trendies, and Townies come from from the affluent South-east, while Geeks or Academics and Scallies predominate in the North-west.
Gangstas are based mostly in London and elsewhere in the South-east, while Skaters predominate in the Midlands and a substantial number of Goths hail from the Eastern Counties and Yorkshire.
BADGES OF BELONGING
The marketers' list of youth tribes, with comments by London teenagers AcademicsGeeks: Also known as neek, boffins, boffs or bodkins. Little interest in music or fashion and prefer to be inconspicuous. They like computers, comics and drawing.
Gangstas: love hip-hop stars such as 50 Cent, designer brands and "bling".
It's all about attitude ("tude") and swagger - not necessarily criminal behaviour, but "rude boys like to jack (rob) people's phones and stuff".
Goths: vampire lookalikes with a penchant for black clothes and nail varnish, whitened faces and piercings. Idols are Marilyn Manson, The Cure and The Sisters of Mercy; there's a big, if faintly paradoxical, stress on individuality.
Moshers: jump around to loud rock music from grunge to metal. They love Nirvana and the late Kurt Cobain and Jet, Kasabian, System of a Down - "anyone sweaty" - are current favourites. The look is band tour T-shirts, baggy trousers and "spiky hair, chunky chains".
Indies: nicely spoken middle-class kids who like "indie" (ie mildly adventurous an d literate, but rarely independently-released) guitar groups: Bright Eyes, The Killers, Razorlight, Coldplay ("but they've sold out"). Unisex floppy hair and baggy trousers and an "I'm listening to the music" look.
Townies: like dance music "like you get at Ayia Napa". UK garage for boys, "Kylie and Justin Timberlake for girls". Ben Shermans for boys, pink crop-tops and the "Essex facelift" (tight ponytail) for girls; traditional girl-boy roles, football, cars and the odd fight. Mostly white.
Scallies: North-west only. Too young to drive but obsessed with cars. Girls like big gold hoop earrings and the "Essex facelift". Boys dress in casual sportswear and caps (back to front). They play hard house and original "Madchester" anthems as well as mainstream chart hits.
Skaters: mostly boys. They listen to Green Day and Blink 182. Greasy hair, skate labels and outdoor brands like O'Neill. They skate, watch skating videos or play skating video games.
Sporties: "nice kids" whose parents think they're great. They play in teams and follow sports. They like "the softer end of hip-hop like R Kelly or Usher" and wear smart tracksuits.
Trendies: Mini Kate Mosses or Pete Doherties. Dedicated followers of fashion from very hip, no-brand designers. Always into the latest music or club. You'll never keep up, so don't try.
Others: "There's religious ones who stay in their own faiths, like the black evangelicals and Muslims and Catholics and Orthodox Jews."
buff - pretty, attractive
nang - good
sick - very good
raw - amazing
phat - big ("that jump was phat")
deep - good or bad
buttersbuttock - ugly
dark - nasty
brass - horrible
link - go out on a date
bell - phone up
blud - mate
brere - any person who is OK
dicksrudes - people outside the group, disliked
safe - easy to get on with
loners - those with no friends