It became commonplace during the twentieth century to regard the age of forty (or more recently fifty) as a tipping point in the life cycle, a moment when many people could begin to shed the financial, domestic, parental and occupational worries of youth and middle age and look forward to a more serene and comfortable period of their lives. The belief that life after forty might present opportunities for, rather than obstacles to, happiness was given legitimacy by a post-Second World War culture that considered increased consumption and economic growth, at least in the West, as the primary route to self-realisation and emotional fulfilment. Made possible partly by increased life expectancy, the crisis of middle age was recast as an epiphany, a moment of temporary imbalance that was necessary if age-related cognitive and economic decline were to be effectively reversed and individuals inspired to achieve the highest levels of personal satisfaction and well-being.
The origins of late-twentieth century convictions that life begins at forty were, however, less emancipatory than we might imagine. Rather, they were rooted in reactionary attempts to preserve political stability, economic productivity and family unity. Four days after the American army entered the First World War in 1917, Mrs Theodore Parsons was interviewed by The Pittsburgh Press, a local daily newspaper. The author of manuals that encouraged children and young women in particular to embrace physical education as a means of cultivating intellectual advancement, health and beauty, Parsons tied her educational creed to the urgent need for women to train themselves for the `duties that war time may bring’. `The mothers of a nation’, she argued, `are its supreme asset and as civilization advances it will be as natural for a nation to maintain its mothers as it is to-day to support its army and navy.’ Parsons’ conviction that women, as well as men, were critical to the war effort was not restricted to the young, but extended to the middle aged and elderly.
‘Most old age is premature, and attention to diet and exercise would enable men and women to live a great deal longer than they do to-day. The best part of a woman’s life begins at forty.’ 
Parsons’ words constitute the first modern reference to forty as a transitional age in the fight for freedom and happiness. But her aim was only incidentally the promotion of individual well-being. More important for Parsons and her contemporaries were the social and military benefits of healthy ageing. The notion that life, rather than death, began at forty was taken up most prominently by Walter B. Pitkin, Professor in Journalism at Columbia University. Pitkin situated his self-help dogma in the context of an emergent American dream. Science and technology had increased life expectancy, reduced the need for heavy labour in the home and workplace, and made leisure a genuine possibility for many Americans. ‘At forty’, he promised in 1932, `you will be wiser and happier than at thirty. At fifty you will be clearer, steadier, and surer than at forty.’  Of course, the collective benefits of enhanced individual health and wealth were evident: greater consumption of services and goods would increase productivity and boost the American economy, fuelling further technological development and economic growth in a cycle of expansion. Couched in capitalist terms, here perhaps were the seeds of the narcissistic veneration of the midlife transition that triumphed after the war.
In Britain, inter-war attention to the change of life in men and women around the age of forty adopted a different, but no less reactionary, complexion. During the 1930s, Marie Stopes addressed the effects of ageing on married couples. In Enduring Passion, first published in 1928, and Change of Life in Men and Women, published eight years later, Stopes questioned the inevitable decline in sexual health and satisfaction that appeared to beset previously passionate couples. The notion of a crisis around menopause (or the equivalent decline in male virility), she argued, had been exaggerated by popular medical writers. By preparing more effectively for the challenges generated by the unfolding stages of life, it was possible to prevent what many people regarded as the inevitable conversion of ‘happy lovers’ into ‘drabby tolerant married couples’.  Stopes’ formula for surviving the crisis of middle age became one of the foundational principles of the marriage guidance moment, a development that originated in the late 1930s but subsequently emerged as one of the key features of a post-war settlement intended to restore the stability of the nuclear family.
It did not take long after the Second World War for these conservative dreams of social coherence and domestic stability to be destabilised, but covertly reinforced, by the rampant individualism of the marketplace. ‘Forty-phobia’ became an advertising slogan for companies selling nerve tonics that promised to help patients ‘feel younger as they grow older’.  For men in particular, the purchase of household goods, cars, holidays and suburban houses was promoted as a means of blunting the frustrations created by the contrast between the excitement of conflict and the boredom of corporate and domestic life, a phenomenon neatly captured in the post-war fiction of Sloan Wilson and Joseph Heller.  Self-fulfilment and its spiritual benefits became the mantra of popular advice books aimed at the disaffected, but affluent, middle classes struggling to redefine and relocate themselves in a changing world.
One of the fruits of this process was the creation of a novel expression of self-discovery: the midlife crisis. Coined in 1965 by the Canadian psychoanalyst and social theorist Elliott Jaques to describe psychodynamic collapse triggered by fear of impending death, the term rapidly came to define midlife madness, a powerful tool for both explaining and legitimating the search for personal fulfilment during the middle years.  The cost in terms of other people’s happiness was regarded by many as less important than the self-realisation, emotional emancipation and spiritual awakening that the crisis supposedly made possible. But `la crise de la quarantaine’, as it became known in France, was not embraced as a means of enabling healthy ageing in women, as Parsons had anticipated, or as a pathway to a more contented and durable marriage, as Stopes had hoped. Shaped by late twentieth-century obsessions with the autonomous individual and the gospel of consumption, the notion that life can begin again at forty has been used to reinvigorate a Western capitalist economy that can only be sustained by prolonging productivity and encouraging spending across the whole life course.
 `Now is the time for all women to train for the duties that war time may bring’, The Pittsburgh Press, Tuesday 10 April 1917, p. 20; Mrs Theodore Parsons, Brain Culture through Scientific Body Building, (Chicago, American School of Mental and Physical Development, 1912).
 Walter B. Pitkin, Life Begins at Forty, (New York, McGraw-Hill, 1932), pp. 174-5.
 Marie Carmichael Stopes, Enduring Passion, (London, Putnam, 1928); Marie Carmichael Stopes, Change of Life in Men and Women, (London, Putnam, 1936).
 An early example of this advertising strategy is `Forty-phobia (fear of the forties)’, The Times, 28 April 1938, p. 19.
 Sloan Wilson, The Man in the Gray Flannel Suit, (Cambridge, Mass., Da Capo Press,  2002); Joseph Heller, Something Happened, (London, Jonathan Cape,  1974).
 The midlife crisis is the focus of on-going research, the results of which will appear in Mark Jackson, The Midlife Crisis: A History, (London, Reaktion, forthcoming).