There is a box of dark chilli chocolates open on the table next to me, and it will be emptier by the end of this column. This by way of declaring an interest: January is grim enough without going on a diet, too. Unless you're one of the 28.9 per cent of women who would rather fit back into their old jeans than get promoted, according to one of those spurious surveys pumped out to fill the New Year news vacuum. For what is the boring old feeling of being good at what you do, beating the competition, learning something new, compared to the thrill of being slightly thinner, eh?
What is depressing about this is not just the usual reminder of the pressures to conform to a half-starved, age-defying female aesthetic. It's the self-absorption. At least work can (sometimes) be for the benefit of others: dropping a dress size is often only a triumph for the wearer.
Yet picking on dieters is unfair. For January is the month when many of us turn in on ourselves and usually find something wanting: the season of gym memberships and self-help books, purple-faced novice joggers and queues for relationship counselling. For a few weeks at least, we fervently believe in new beginnings, positive thinking, and the mantra "You can do it" - even if, by February, we often conclude that we can't (or at least can't be bothered).
Blame the victim
All of which makes the American writer Barbara Ehrenreich's new book, the subject of a lecture at the Royal Society of Arts this week (11 January), an unseasonal blast of fresh air. Smile or Die: How Positive Thinking Fooled America and the World promises a blistering attack on the cult of can-do and its supposed power to change fortunes, targeting American sacred cows from churches to Oprah.
The book was born of Ehrenreich's irritation at the pressure she felt under to be upbeat following her diagnosis with breast cancer. (Contrary to popular belief, the evidence is far from clear that a positive attitude actively helps sufferers beat the disease.) Her dissection of some of the vaguer mumbo-jumbo associated with positive psychology feels overdue.
But the bigger argument is that pretending anyone can get what they want so long as they just believe in it enough is both illusory and potentially damaging. It suppresses natural anger at injustices, blaming the victim (if you fail, well, you just weren't visualising success hard enough) instead of tackling the systemic obstacles and inequalities that perhaps thwarted them. According to Ehrenreich, it lets society off the hook.
Having waded recently through several perky self-help manuals for working mothers, sent by kind and well-meaning people after I quit my full-time job, I get the point.
Many of the American versions major in rousing pep talks and faintly demented timesaving tips, rather than railing at how proper paid maternity leave is still not a universal right in the US. One feels American mothers deserve fewer zany speed relaxation techniques and more effective lobbying of Congress.
Ehrenreich is puncturing a particularly American balloon: here in the land of Eeyore, we are less prone to fetishising the pursuit of happiness. Yet there are signs that a similar ethos is taking hold in Britain, from the reality TV phenomenon that was Jedward - very nearly proof that anyone can succeed if they want it enough - to the media treatment of amputee soldiers.
Yes, it is enormously uplifting to read about heroic survivors running marathons on artificial limbs; but do such stories put unfair pressure on those whose injuries left them too bitter and depressed to follow suit? Beware of positive thinking that is used to make the rest of us feel better about them. And Ehrenreich's underlying question of how much responsibility individuals have for creating the good life, and how much is up to the state or wider society, is highly relevant to British politics.
Return to reason
Over the next decade, governments will need to decide how much social welfare recipients can be expected to do to help themselves. Should employers go further to accommodate working parents? Or should families figure things out for themselves? Politicians will need to decide if tackling climate change depends on individuals changing their habits, or on big business and the state. And so on.
The trouble with a backlash against positive thinking is that the alternatives - pessimism, despair - aren't terribly appealing. Who wouldn't take the brief elation of the Obama honeymoon, when it seemed that anything was possible, over the inevitable disappointment which followed? Yet now that the "Yes, we can" president has had to accept that, actually, sometimes he can't, perhaps a more pragmatic but still effective administration could rise from the ashes?
According to Ehrenreich, the flipside of positive thinking isn't negativity but calm reason - a rational approach to risk, say, rather than the irrational exuberance that characterised the banking bubble. Another alternative is channelling that reforming zeal into the outside world, rather than on to ourselves.
There's nothing wrong with changing your life for the better. But after a decade of bingeing on self-improvement and its close cousin self-loathing, we could maybe spare a little more anger for the injustices around us. And yes, that does mean having one's chocolate and eating it. So long as it's fair trade.
Gaby Hinsliff is former political editor of the Observer