In the opening years of the 20th century, the American psychologist G. Stanley Hall published the first full survey of what he called ‘Adolescence’. At over 1500 pages, the two volumes collated an enormous amount of data on this ‘second stage of life’, between childhood and adulthood, which Hall defined as being between the ages of 13 and 24. Hall at once marked this crucial stage as one of stresses and storms – an idea taken from the 18th century Romantics – and one that needed care and guidance.

Indeed Hall proposed nothing less than the creation of a new stage of life that would increase dependency and delay entry into the world of work: ‘As civilisation advances, education broadens. The school years lengthen inevitably as the community tones up its ideals.’ Any attempt to restrict the time spent in school or college was ‘an attempt to return to savage conditions. The estimate of any educational system must be based upon its success in bringing young people through adolescence with (the) greatest perfection of development’.

In Hall’s vision, adolescence was inextricably linked with the potential rise of a young continent: ‘We Americans are a mixed race. This makes the period of adolescence in America unique. Where nature is kept pure this period of ferment is accomplished quickly and with little trouble, as among the Jews and the Germans. The period of adolescence is prolonged in America because of mixture of blood, and if we survive the trials and dangers of this period, we will make the grandest men and women the world has ever known.’

With a strong academic impact and crossover sales, Adolescence accelerated the demand for the widening of educational opportunities and opened up America’s eyes to this omnipresent but ill-defined state. At the same time, Hall presented to America a vision of itself as a young country that would be a beacon for the forthcoming century: ‘The very fact that we think we are young will make the faith in our future curative, and we shall one day attract the youth of the world by our unequalled liberty and opportunity.’

By the time that Adolescence was published in 1904, several factors had alerted adults and educators to the possibility that youth could be both dream and nightmare. Young people were a visible and threatening presence on the streets of most cities in Europe and America, and were already the subject of exposés and press panics: the Growler Gang pictured by Jacob Riis in New York, the Apaches of Paris and the Hooligans and Scuttlers of Britain – new urban types who were both dangerous and dressed in bizarre clothes.

Indeed, the first definitions of any separate stage of life between childhood and adulthood had come from criminology. The phrase Juvenile Delinquent had been coined in the mid-19th century to describe the new phenomenon of age- and class-specific crime, as young working-class men and women began to act out new opportunities caused by urbanisation and mass industrialisation – the lack of parental supervision, the fact that new industries put money in their pockets. Adrift from old norms, they were harbingers of a new and unsettling future.

There were also books that mapped the adolescent experience from within. Published in 1887 after her premature death, Marie Bashkirtseff’s diaries spoke frankly of teenage frustration and prefigured the celebrity culture of the 20th century: ‘If I do not die young I hope to live as a great artist; but if I die young, I intend to have my journal, which cannot fail to be interesting, published,’ she wrote. ‘I dream of celebrity, of fame.’ The private diary would become the most intimate and, in some ways, the truest expression of the adolescent experience.

Announced not only by Hall’s Adolescence but also J. M. Barrie’s Peter Pan and Oscar Wilde’s The Picture of Dorian Gray, the new status of youth was unsettling, and adults and governments began to think in terms of its guidance control. The 1900s saw the institution of the Boy Scout movement in both the US and the UK, and the formation of militaristic youth groups in Germany, most notably the Jungdeutschlandbund, which, in 1914, numbered around 750,000 members – the largest youth group in the world.

The First World War in Europe brought the emerging consciousness into further sharp focus. With the young having been sent to die in their hundreds of thousands, there was at once a sense after the war that youth was both scarce and precious and that as a principle in itself it could help to chart the post-war world in new ways: as the artist Percy Wyndham Lewis wrote, ‘Everyone wished to be, as it were, new born. To blot out the past, especially the pre-war, that was the idea’.

There was much talk in Europe of the ‘Generations’ being in conflict with each other: the pre-war Generation who had sent the young to die; the wartime Generation who had suffered so much; the post-war Generation who wanted nothing to do with idealism and sacrifice but just wanted to have a good time as though there was no tomorrow. These positions hardened into quasi-ideologies, of which the most potent in the 1920s was hedonism – the partying mode epitomised by the Bright Young Things in the UK and the Flappers in the US.

In America, the emergence of more young people in secondary and tertiary education fuelled the 1920s youth type known as the Flapper. Young women were allowed more freedoms and, as enthusiastic consumers, helped to create the idea of a youth market. This was tied into the new mass media, movies and radio, through the popularity of jazz bands and film stars like Rudolf Valentino, whose death in 1926 saw a mass frenzy on the streets of Manhattan as he lay in state. His fans were known as Sheiks and Shebas, after his most famous film The Sheik.

At the same time, the 1920s also saw the emergence of European ‘back to nature’ youth groups. In Germany the Wandervögel (Wandering Birds) had emerged in the years before the war but by mid-decade ran the gamut of proto-‑hippie, naturist gangs to nationalist ‘back to the soil’ organisations. In the UK groupings like the Kindred of the Kibbo Kift and the Woodcraft Folk attempted to fuse folk ethnography with practical ‘back to the land’ skills and hieratic costume in an attempt to roll back industrialisation and urbanisation.

However these new types paled before the new mass media culture emanating from the US, where the youth market was already well established. The emergence of a new, pan-youth class was encouraged by the increasing number of college students in the US – a 400% rise between 1890 and 1924: a process whereby young people left their hometowns and met others from different areas throughout the country. What they had in common was their youth and that was interpreted in terms of movies, magazines, music and alcohol.

Pleasure on their own terms might have been a unifying theme for many 1920s adolescents but this was curtailed, as was much else, by the Stock Market Crash of 1929. As the Depression deepened in the years that followed, there was a fresh concentration on youth – who were at the sharp end of this economic disaster. Throughout Europe and America, there were grave concerns about political polarisation, as the Western World split between the emerging threat of fascism and its communist counterpart. ‘Which side are you on?’ became a common theme.

After Hitler and the National Socialists stole power in January 1933, this conflict deepened. In Germany the Nazis instituted a gender segregated national youth group, the Hitler Youth for boys and the Bund Deutscher Mädel for girls, while fascists and communists battled it out in the streets of Britain and America. In Spain, this turned into total war in the Civil War of 1936 and the following years, which was used by the Nazis – who supported General Franco – as a dry run for the conflict that they intended to initiate.

America’s response for youth in the Depression was to firstly involve them in nationwide regeneration projects – through the Civilian Conservation Corps – and secondly to ensure that greater numbers of 13-18 year olds entered and stayed in school. The unintended by-product of this was the creation of an ever larger pan-youth class than the college students of the 1920s, as the younger cohort of American adolescents went through the high school system and began to create their own peer culture.

Like the 20s generation, these adolescents of the later 1930s liked jazz, but this time their numbers and the vigour of the new music coalesced to create what could be called the first mass youth style. Triggered by the success of the Benny Goodman Orchestra – who broke through into the national media during 1937 – swing music and its culture swept through America’s youth in the years that followed. Goodman’s vibes player, Red Norvo, described it as ‘a tempo that inspires the listener to accelerate in rhythm with an ultramodern swing’.

Like the 20s generation, these adolescents of the later 1930s liked jazz, but this time their numbers and the vigour of the new music coalesced to create what could be called the first mass youth style. Triggered by the success of the Benny Goodman Orchestra – who broke through into the national media during 1937 – swing music and its culture swept through America’s youth in the years that followed. Goodman’s vibes player, Red Norvo, described it as ‘a tempo that inspires the listener to accelerate in rhythm with an ultramodern swing’.

With swing, the tempo of teen life sped up. The difference between the jazz youth culture of the 1920s (hot jazz) and the 1930s (swing) was that many more adolescents were involved in the latter thanks to the high school peer culture. At the same time the mass media – movies, magazines, jukeboxes and, in particular, radio – had a much wider sweep than it had done a decade before. As the editors of a 1939 teen fanzine called Jitterbug observed, ‘Jazz is a major industry today and depends on mass consumption.’

Post-war children tend to think that they invented everything but all the elements of what we now consider to be youth culture were in play with swing. It was a mass form of entertainment and communication: in 1938, 100,000 swing fans packed a stadium in Chicago for a Swing Jamboree. As it swept through America’s youth in the late thirties, it brought along with it many elements from its parent black culture: the language (jive talk), the dances (jitterbugging, the Lindy Hop), and the clothes (zoot suits). It was a complete youth world unto itself.

By 1939, swing was beginning to spread into Europe but the events of the next few years would bring it into sharp prominence. During that year, something like 85% of all German youth between 12-18 were in the Hitler Youth and BdM. Trained for war, they were eager conscripts when hostilities broke out that September and, for a couple of years, the Nazi war machine swept through much of Europe – imposing its own totalitarian rules on its conquests with local puppet regimes in France, Norway, and Poland.

But in both Nazi Germany and occupied North France, swing music and its culture provided a rallying point for the small percentage of brave teens who decided to resist nationalism and imposed totalitarianism. In the early 40s, the Hamburg Swings openly defied the Nazis by refusing to wear uniform and attending prohibited swing concerts, while in Paris the Zazous infuriated the Nazi occupiers and the French fascists by wearing exaggerated, American-style clothes, listening to swing, and refusing to submit to militarism and forced labour.

There was a distinct sense that swing music, with its strong roots in the underdog culture of American negroes (as they were known then), was an intrinsically democratic and liberal form. As the Second World War progressed, it became integrally entwined with American values as the country positioned itself as the bastion of freedom against the Nazis and its young fans took the message to heart: as one American wrote to his pen pal in Germany in the year that war broke out, ‘When it comes to art, and swing is an art, there are no lines.’

After late 1941, America went through internal convulsions. With the upheavals caused by the war effort (industrialisation, internal migration, lack of parental scrutiny), the behaviour of young people – i.e. the males under 18 and young women – became scrutinised: by 1943 there were scares about drugs, racial violence (the Zoot Suit Riots), Victory Girls (young women offering themselves to servicemen) and juvenile delinquency. Even the FBI got involved, with J. Edgar Hoover speaking of ‘the creeping rot of moral disintegration’.

Clearly something had to be done about the youth and the answer was right under the authorities’ nose. During the war, the comparatively autonomous American subcultures of the previous twenty years – the college-age Sheiks and Shebas of the 1920s, the Swing Culture of the 1930s – coalesced in the figure of the Teenager. Too young or the wrong gender to be actively involved in the war effort and shielded from the direct effects of the conflict, these young women and young men became avatars of the new American dream.

From the early days of the war, swing culture had developed into a more broadly based youth culture built around music, fashion, cinema and other leisure activities, a culture that, by 1943, was frequently disseminated in the national media: for instance, LIFE magazine’s spread about ‘High School Fads’ in 1944. There were various terms to describe this youth market: ‘sub-debs’, ‘teensters’ or ‘teeners’ – the latter based on the suffix used for the second decade of life: thirteen, fourteen etc.

This appellation was given greater credence by the institution in 1943 of government sponsored youth clubs, ‘Teen Canteens’: an attempt to divert youthful energy to more useful ends by involving the young in the organisation and running of the clubs. At the same time, the power of the youth market – an estimated $750m – was given even more public prominence by the success of Frank Sinatra, whose appearances in theatres like New York’s Paramount occasioned wild fan frenzies that were again widely disseminated in the media.

September 1944 saw the launch of the magazine that pulled all these strands together: Seventeen. Aimed at young women, it was an instant success, selling over 500,000 copies: it codified the new definition of youth with its mix of ‘Young fashions & beauty, movies & music, ideas & people’. The ‘Teenager’ was young, median age 17, and in the American capitalist tradition, a consumer: for instance the magazine was full of adverts for young women’s clothes (the Blum Store’s ‘Teen Canteen’, Saks Fifth Avenue’s ‘Young Circle’).

But it wasn’t quite as simple as that. In Seventeen and in manifestos like Elliot E. Cohen’s ‘A Teen-Age Bill of Rights’ of January 1945, Teenagers were constructed as consumerist and essentially materialist, yet also as democratic – because their country was fighting against fascism – and liberal. Mainstream products aimed at American teens included the 1945 short ‘The House That I Live In’, a film promoting racial tolerance and starring the teen star of the day, Frank Sinatra.

This is where I ended ‘Teenage: The Creation of Youth 1875-1945’. The book climaxes with the end of the Second World War: as well as the terrible events that took place in 1945 – the detonation of atom bombs at Hiroshima and Nagasaki to name but two – that was also the year that America became the dominant power in the Western world. With that ascension came the global propagation of American values, which at that moment professed, and to some extent enacted, what could be called Democratic Consumerism.

In this Year Zero, youth would be at the forefront, in the figure of the Teenager. The old world was dead and the best placed group to flourish in the new era were the young, who had always been held to embody an auspicious future. ‘Their lives are lived principally in hope’, Aristotle had written, while, for Stanley Hall, adolescence was nothing less than ‘a new birth’. In the act of forgetting, which was necessary for the Western World to continue, youth was once again – as it had been after the Great War – exalted as a tabula rasa.

The definitions of youth had gone through many twists and turns since the late 19th century. European nations and regimes had tried to organise adolescents for their own ends: efforts that almost always ended in regimentation and militarism – the syndrome that, at its most extreme, had led the Hitler Youth into suicidal fanaticism. Many artists and writers had tried to imagine what youthful independence might be like, while psychologists had made strenuous efforts to map and control this volatile, stressful state.

Thanks to Stanley Hall’s pioneering research at the turn of the century, America had led the way in its approach to the question of youth. It had seen the first mass adolescent consumer culture during the 1920s, and the first governmental attempts a decade later to organise adolescents in a humane rather than a coercive manner. The two approaches had come together during the Second World War, when the demands of the burgeoning youth market were integrated with social policies that offered adolescents some degree of autonomy.

Coming to prominence through an intricate ecology of peer pressure, individual desires and savvy marketing, the Teenager resolved the question posed by the war: what kind of mass society will we live in? In contrast to fascism or communism, the American future would be organised around pleasure and acquisition: the harnessing of mass production to disposable leisure items like magazines, cosmetics and clothes, as well as military hardware.

The Allies won the war at exactly the moment that America’s latest product was coming off the production line. Defined during 1944 and 1945, the Teenage had been researched and developed for a good fifty years: the period that marked America’s rise to global power. The Teenager was the ultimate psychic match for the times: living in the now, pleasure-seeking, product-hungry, embodying the new global mass society where social inclusion was to be granted through purchasing power.

Over the last 70 years and more, this has been the basic ritual to ease the transition between childhood and adulthood in the West. Many conservative commentators have considered the young as mindless sheep manipulated by unscrupulous businessmen but the Teenage model was designed to include them as part of the process. The producers of clothes, cosmetics and the like realised that by enlisting the young as creative (if not business) partners, they would be more likely to sell products that teenagers might actually want to buy.

The multiple variations on this theme have created the great efflorescence of youth cultures over the last seven decades and have also helped to facilitate the greater social freedoms under which many people in the West have lived. In Britain, the pop culture of the 1960s went hand in hand with progressive legislation concerning divorce, sexual equality, homosexuality, while in America it co-existed with the powerful drive for equality embodied in the Civil Rights, Women’s and Gay Movements.

However, it seems as though this is on the point of change. The post-war reconstruction of 1945 has offered a kind of stability but is now exhausted,subverted from without and within by a rapacious hard right faction. The moral authority of the WW2 winners, America and Great Britain, has been rendered bankrupt by Trump and Brexit. At the same time, the ideal of the Teenager is under threat, tied in as it is to a quick-turnover, high maintenance economic model that is becoming unsustainable in terms of global resources.

The book “Teenage” finished in 1945 partly because it made sense to end with a beginning. I also wanted to present a veiled polemic: this is how we’ve been living but it’s not immutable. Things are moving very quickly and such circumstances force change. In presenting the back story to the model of youth that we are now familiar with, I wanted to show that youth culture is not automatically hedonistic, democratic or even liberal. The Teenager is not necessarily a permanent fact of life.

During the previous seventy years, there were youth groups that were militaristic and nationalist, like the Jungdeutschlandbund in Germany. There were groups that were frankly hedonistic, like the Bright Young Things of 1920s Britain or the College Kids in 1920s America. There were fascists: the Hitler Youth in particular, a compulsory organisation which stated that ‘youth must be led by youth’. There were the ‘back to nature’ groups, like the German Wandervögel or the British Kindred of the Kibbo Kift. These variations are still possible.

It is important to listen to the youth, because they are at the sharp end of the world that adults have created. The old way isn’t working anymore. The current marginalisation of much European youth, for instance, from proper jobs, from entry into the traditional transitions of adulthood (marriage, buying property) and indeed from mainstream politics might create a dangerous state of affairs where extremism flourishes and further destabilisation occurs. From their perspective, who could blame them?