One of the first social rules children learn is the painful necessity of sharing. After the shock of encountering other wants and needs as strong as their own, a child who hands over stickers and sweets to their peers is praised. Yet for adults in the UK, sharing and caring, a glib rhyme that packages an important truth, is no longer a priority. “Compassion is an unstable emotion. It needs to be translated into action, or it withers,” writes Susan Sontag in her essay on observing others’ suffering, and Britain has tolerated inaction about inequality for so long that a shared responsibility for one another’s wellbeing has eroded. If only the housing stock of the UK were more evenly distributed, for example, there would be no housing crisis; no child would even have to share a bedroom. Instead, we now live in a poor little rich country: “A rich country where the average person lives like a poor person.”

Danny Dorling, professor of human geography at Oxford University, fluent with statistics as well as stories, describes this shift as a choice that society could reconsider. Inspired by the 1964 documentary Seven Up!, which followed 14 children born in 1957, Dorling’s book enters the private worlds of seven typical five-year-olds – born in the autumn of 2018 – who represent today’s spread of family income in the UK. These range from “Monday’s child” Anna, an average representative of the bottom 14% of children who has “less than a large posh coffee” spent on her needs weekly, via “Thursday’s child” David, whose dad incessantly worries about his insecure income, to “Sunday’s child” Gemma, daughter of successful corner shop owners yet her father feels the pinch and is flirting with far-right ideas. As a group, children entering primary school in the UK – for whom the most significant ABCs are austerity, Brexit and Covid-19 – have never had it so bad. Not since the Great Depression has the UK been so unequal, home as it now is to the greatest concentration of poor children in Europe.

Rather than wealth, Dorling focuses on weekly disposable income after housing costs, as accommodation is a non-negotiable outgoing and a much greater percentage of income at the bottom of society than at the top. While Seven Up! chose to highlight extreme lives rather than averages across society, Dorling shows how the UK has been “stretched apart” and, moreover, how inequality is starkest for families with young children. He has constructed his seven characters through thousands of data points; they are highly factual fictions. He cleaves to his theme on economic income, explaining that “none of the eight ‘protected characteristics’ enshrined in UK law matter even a fraction as much as income and wealth” when it comes to inequality: whether or not you can afford a winter coat, internet access, heating, holidays, a new kettle if the old one breaks, or a school friend over for tea are what segregates us. Through these windows on each child’s life, Dorling exposes how financial inequity affects housing, education, health, employment, tech access, social care, rent and food. The stress for families of securing these necessities hums through the chapters.

Two cognitive fallacies maintain the status quo in the UK. No matter people’s income, they tend to believe they are closer to the middle of society economically than they truly are. Parents managing below the mean are likely sensitive to “keeping up appearances”, making careful daily decisions, and reassuring themselves it could be worse. Those sitting above the middle still feel that they struggle, and don’t enjoy the security and comfort they would expect better off people to experience. Essentially, we are very bad at ranking ourselves, and society has lost its shared sense of what poverty means, as well as what it means to be rich. This links to the second cognitive fallacy, discussed at length by the late Daniel Kahneman: we are highly sensitive to the threat of losses, more than we are motivated by gains. It is little surprise that the relatively wealthy are anxious about immigrants misusing services, just missing out on the benefits of private school, and bemoan falling standards in society, fears that are largely unfounded and resistant to the many privileges these families do enjoy.

So who’s to blame? Dorling is rightly scathing of Tory cuts, the “tearing apart of British society from the 1970s”, and the rampant cronyism that went unchecked in the pandemic. Scorn is reserved also for the media, who prefer to run stories about the “undeserving poor” rather than applauding the majority of people trying to get by within legal means who are failed daily by a hostile system. Fetishising stories of the richest and poorest 1% warp our perspective about what modern Britain really looks like, and miscasts those who are struggling as feckless.

Dorling wants to be hopeful that society might become more compassionate, but it’s not clear how (Labour’s end of tax breaks for private schools have arrived since Dorling’s time of writing, which he would no doubt applaud). But perhaps compassion is not what is needed now, nor its close cousin, sympathy. We need to believe Dorling’s statistics and these stories. Really believe them, in the way that we believe our own about what makes life a struggle. Dorling’s book, ultimately, is relying on its audience of Sunday’s children, who may think of themselves as “normal people” but have been privileged from birth and continue to enjoy the legacy of that early advantage. Of all the books I’ve read this year, Seven Children has stayed with me so intensely it feels like a form of haunting. I assess children in A&E as part of my job in the NHS, and now I notice more than ever that their clothes are dirty not with the stains of play but the grime of unwashed wear. It cannot go on, and yet it does.

Kate Womersley is a doctor and academic specialising in psychiatry

• Seven Children: Inequality and Britain’s Next Generation by Danny Dorling is published by Hurst & Co (£14.99). To support the Guardian and Observer order your copy at guardianbookshop.com