For all those who have occasionally wondered just what might lie behind the eternal sunglasses of the famously scary Anna Wintour, the author of a new biography of the longstanding editor-in-chief of American Vogue has momentous news: it seems that there is, after all, “a person there” (as opposed, you understand, to a robot programmed by the ghost of Oscar de la Renta). But while journalist Amy Odell has indeed found several witnesses willing to testify on the record to the existence of this corporeal being, she is, alas, unable to go much further; to explain what motivates Wintour, let alone to reveal what keeps her awake at night (assuming she can tell it’s the night). Her book might well be based on 250 sources and come with notes longer than the concordance to Thomas Malory’s Le Morte d’Arthur. However, full disclosure, it is not – unless, of course, the reader was hitherto unaware that Wintour’s “ability to empathise is debated”. Debated! The word would come with all the wit and understatement of vintage Maison Margiela were it not for the fact that it is used completely without irony. Then again, its author’s refusal to poke fun at anything, however ludicrous, is also the only reason I enjoyed her book. If the pages (and pages) she devotes to Wintour’s assistants – young women who must not want to be writers and whose job it is to make sure that her full-fat latte and blueberry muffin (an item usually left uneaten) are waiting on her big, white desk every morning – are comprehensive to the point of tediousness, it’s hard not to laugh at her utmost seriousness, even when dealing with the mad and the risible. Having noted, for instance, that after the 9/11 attacks, Wintour went back to work immediately, she quickly adds that this was hardly unusual: after a facelift in 2000, she returned to the office – even more amazing! – with bruises still visible. Yes, Vogue’s staff were uncomfortable at being expected to do similarly, but they were also, thank goodness, able to make “one extraordinary step toward self-care” by wearing flats rather than heels “in case they had to run down the stairs”. Wintour has said that she relishes America’s classlessness, a statement that somewhat glosses the fact that she got her own start via her father, Charles Wintour, an Evening Standard editor. Having left her private school in London in 1966 – university was not for her – it was daddy who helped her to get a job at Harpers & Queen, where she started, sunglasses and bob already in place, as a fashion assistant aged 20 (the magazine’s then editor-in-chief knew her father). But this isn’t to suggest she was without gumption; ambition and a certain kind of tight-lipped stoicism are her chief characteristics, according to Odell. Furious at having been passed over for promotion at Harpers, five years later she headed to New York with her then boyfriend, where she eventually landed the role of fashion editor at a magazine owned by Bob Guccione, the founder of Penthouse. Viva was, she knew, a little on the tawdry side, but its fashion pages, dominated by “Siberian peasant outfits”, were also ripe for transformation. Wintour favoured models posed in country settings – hay, tractors, chunky sweaters – but she also liked “edge”. An issue of 1977 included an image in which a model in a baby doll dress and bonnet could be seen on her hands and knees being fed a bottle of milk by the man posing above her. Eat your heart out, Gloria Steinem. On she clambered. Stints at Savvy and at US Vogue in time led to her returning to London in triumph to edit British Vogue. But that title then, as now, was small fry compared with its Condé Nast stablemate, and after a disastrous period running House & Garden in New York, she finally stole American Vogue from under the nose of its beige-loving editor, Grace Mirabella, in 1988 – and there she has remained ever since, surviving every rumour, every advertising downturn, every editorial calamity. In addition to her role at Vogue, she is now Condé Nast’s chief content officer and artistic director. The moment of greatest peril came, arguably, when her glorious realm’s lack of diversity found itself under attack from the social justice movement in 2020, but she simply apologised and sailed on. Wouldn’t she rather, at 72, be spending time with her grandchildren, or playing tennis at her Long Island retreat? Or even – imagine it! – trying another, completely different job? Apparently not. I love fashion, in the sense that I like clothes (I’m writing this piece in a boiler suit, gold Birkenstocks and vintage Norman Hartnell jewels, if you don’t believe me); long ago, I was the deputy editor of a glossy magazine myself. But my disappointment with those whose self-appointed job it is to disseminate the activities of the industry and its stars grows incrementally, and Odell is no exception. While her interviewees assert all sorts of things about Wintour – the marvellousness of her taste; her brilliant sense of humour; the fact that her ex-husband, David Shaffer, was her “svengali” - only rarely does she back their statements with evidence. As for Wintour’s mean side, her proclivity for ghosting people, freezing their innards with silence (everyone knows about her fallout with André Leon Talley, once her cherished lieutenant), Odell has an alarming tendency to give sympathy to the undeserving.. In 2010, Wintour decided she wanted an interview with Asma al-Assad, the wife of Syria’s dictator president, whose look she apparently liked. The job was assigned to Joan Juliet Buck, a former editor of French Vogue and Wintour’s friend of five decades. All Vogue interviews are basically puff pieces, and this one, published just as the Arab spring was beginning, was no exception; Buck wrote breathlessly that Assad had won his country’s election with “a startling 97% of the vote”. When it was published, a horrified backlash naturally followed, soon after which Buck found that both her friendship with Wintour and her writing contract were at an end – a severing that, by Odell’s telling, comes off like a straightforward scapegoating when, in truth, you cannot put a paper between the repulsive indifference of either woman. They’re all in it together, these people, tied in a silk knot that this book, like so many others before it, does not even try to unpick. Anna: The Biography by Amy Odell is published by Allen & Unwin (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply