With some difficulty, I manoeuvre my extra-long double buggy — dubbed “the gondola” — into a room cluttered with plastic toys. The psychotherapist gets up from her beanbag to help me to fold it up. I introduce her to Isaac and Imogen, my seven-month-old twins, and then put them down on the mat. The babies, blissfully unaware of the therapist’s eyes, proceed to give the toys a good gumming.

I am at the Oxford Parent Infant Project (Oxpip), a charity that offers psychotherapy to parents and children under the age of 2 that was founded by the eminent child psychotherapist Sue Gerhardt, whose new book, The Selfish Society, comes out this month. In her first book, Why Love Matters, she argued that love was essential to brain development. It was a runaway success, selling more than 15,000 copies in its first year.

The Selfish Society, however, is more controversial. Drawing on a pick-and-mix of everything from politics to macroeconomics, Gerhardt mounts a furious attack on capitalism. She blames it for “eroding our social bonds”, creating an “impoverished emotional culture”, where “looking out for No 1” is the norm and parenting is undervalued.

This leads to her most inflammatory point: putting children in a nursery before their second birthday is profoundly damaging to their mental health. Our capitalist Government, she argues, is so keen to get mothers back to the business of wealth-generation that the cheap solution — nursery — is promoted, although it makes children vulnerable to “personality disorders” later in life.

At Oxpip, however, there is no sign of such contentious views. The therapist, Joanna Tucker, is careful not to condemn nurseries. “Mothers face a range of difficult choices,” she says. “We’re not here to pass judgment on their decisions.” But doesn’t she share Gerhardt’s anti-nursery ideals? There is a pause. “Tell me about any difficulties you have had with parenthood,” she suggests.

Having twins and a toddler, I tell her, although wonderfully fulfilling, has involved a level of stress that no man should have to deal with. When all three are crying, it’s impossible. Even if both parents are on duty, one child is still left over. At such times I panic and feel desperate to be out of earshot.

“That’s quite normal,” says Tucker. “Babies’ cries are biologically designed to make their parents feel uncomfortable.” I’m surprised at how reassured I feel. “You clearly have a strong bond with your twins,” she continues. “I can observe how you’re letting them play, but at the same time are attentive to each of their needs. A great deal of anxiety is produced when you worry that your experiences are not normal. Just having things ‘normalised’ can be a relief.”

But many of Oxpip’s clients require rather more than normalisation. “Some parents need a lot of help,” says the therapist. “Often, they unconsciously re-enact issues from their own past in their relationship with their children. we call this ‘ghosts in the nursery’. If a mother has suffered from childhood anorexia, for example, she might believe that her child is greedy. We try to free children from their parent’s ghosts by helping the parents to see what’s going on.”

One of Gerhardt’s main therapeutic techniques, used extensively by Oxpip, involves the use of video. “We film a parent-child interaction and play it back. Often the parent notices immediately where they’re going wrong,” says Tucker. “I once had a client who thought her older son was very difficult. When I filmed them, the video captured her giving the boy a most awful look, as if he was something really unpleasant. When the mother saw it, she was rather horrified. She also noticed that her son was constantly trying to get close to her, but she was ignoring him. Once she realised he loved her, she was able to love him back. We got a better cycle going.”

Projects like Oxpip can clearly make a profound difference to people who are struggling with parenthood. But why has Sue Gerhardt upped the ante so dramatically in The Selfish Society? I put the question to her at her cottage in north Oxford, over coffee that she has made on her Aga.

“Society has become selfish,” she says. “Greed and materialism have completely smothered empathy and moral living. If nothing is done about it, humanity won’t survive.” Decades of experience as a child psychotherapist, as well as the study of neuroscience, has led her to believe that most social problems can be traced back to the “inadequate” state of early childhood care in Britain, with its overt preference for nursery.

“The first two years of life are when the brain’s emotional systems are being set up,” she explains. “That’s when an area of the brain called the prefrontal cortex is developing, which enables us to be aware of both our own and others’ emotions. Sensitive and responsive parenting causes a chemical called dopamine to be released in the child’s brain, which enables the child’s emotional awareness to develop.”

In a nursery, Gerhardt argues, this developmental process can be stunted. “In the 1940s,” she says, “there was a study of toddlers isolated from their parents in a tuberculosis hospital. They went through stages of adapting to their emotional deprivation — first protesting and looking for their mother, then growing despairing and listless, and finally becoming emotionally detached. In a nursery, a similar process can occur. In neurological terms, the development of the frontal cortex is being hampered, and this creates an emotional black hole. When the child grows up, he or she is likely to crave emotional substitutes — consumerism, money, or drugs. It is fertile ground for personality disorders.”

Although my own children are being looked after at home, I know many mothers who don’t want to — or can’t — leave the world of work. I can only imagine the amount of guilt they would experience on reading The Selfish Society. Isn’t Gerhardt forgetting that other factors are involved, such as the need to make money or sustain a career? “I’m not suggesting it’s all the parents’ fault,” Gerhardt explains. “The Government needs to stop promoting nurseries so aggressively. We need to introduce a two-year state-funded parenting wage, set at the level of the average income, to be claimed by either parent, or shared between them. And we need to reform employment legislation so that employers are forced to keep a mother’s job open, and to offer flexible working hours.”

All this would be expensive. But Gerhardt tells me that recent studies by the New Economics Foundation prove that greater investment in early childhood care makes economic sense. “Every pound invested early on would save £7 of social costs within ten years,” she explains. “We could slash our spending on prisons, depression-related NHS costs, social services and so on.”

Gerhardt’s theories certainly seem to be borne out by research. But I wonder if it can really be true that so much of our personalities are created by our early years? Statements such as “people who are well nurtured might be less interested in keeping up with fashion” seem oversimplified.

Oliver James, the clinical psychologist and author, broadly supports Gerhardt’s understanding of childhood development. “Care in the first year is indeed linked to a likelihood of personality disorders,” he says. “When a parent figure is unloving or frequently absent, a child does not learn to form healthy relationships. This causes a weak sense of self, which may develop into a greedy, boastful, exhibitionist, fragile or febrile personality.

“I don’t believe that children can only be cared for by their mothers — a regular childminder, for example, might be almost as good — and brain development certainly continues until the age of six and beyond. But it is indisputable that children need a consistent, loving primary carer if they are to develop a well-functioning brain. That’s why I also support the two-year parenting wage.”

The Selfish Society contains much that I find far-fetched. The relentless criticism of selfishness and capitalism seems rather over-the-top, and at times Gerhardt extends her psychotherapeutic theories too far (she asserts that “Bush ’n’ Blair” must have been mistreated as babies).

Yet, as I navigate my gondola out of Oxpip, I’m struck by the sense that hundreds of people have emerged from these doors with stronger bonds with their children, and a renewed sense of confidence in their parenting. I feel “normalised”, happier and more relaxed about my relationship with my twins. As for Isaac and Imogen, exhausted by the range of new objects they have masticated, they have fallen asleep.