Postwar: A History of Europe Since 1945

by Tony Judt

The most immediately obvious symptom of this new adolescent spending power was sartorial. Well before the baby-boom generation itself discovered miniskirts and long hair, its immediate predecessor—the generation born during the war rather than just after it—asserted its presence and its appearance in the gang cults of the late Fifties. Dressed in dark, skin-hugging outfits—sometimes leather, sometimes suede, always sharply cut and vaguely threatening—the blouson noirs (France), Halbstarker (Germany and Austria) or skinknuttar (Sweden), like the teddy boys of London, affected a cynical, indifferent demeanour, something between Marlon Brando (in The Wild One) and James Dean (Rebel Without a Cause). But despite occasional bursts of violence—most seriously in Britain, where gangs of leather-clad youths attacked Caribbean immigrants—the chief threat that these young people and their clothes posed was to their elders’ sense of propriety. They looked different.

The reason "subcultures" started in the 50s is because that's when young people first had disposable income.