One thing you can be sure of when childcare is the subject of debate is that reason goes out of the window. My heart sank last week when I saw the headlines about Unicef’s latest report on education and childcare in the developed world, all along the same lines: “British children suffering as mothers are forced back to work”. Oh, please.

Unicef’s study, carried out by the Innocenti research centre in Florence, ranked Britain joint 11th out of 25 countries – behind France, Hungary and Slovenia – for the quality of its childcare policies and provision for young children. The categories are pretty coarse. It suggested that government policy, in extending nursery care, may be running counter to “today’s knowledge of the critical development needs of very young children”.

But the science tells us surprisingly little. What matters to the development of young children is the relationship they have with their parents, primarily their mother. They need to establish a mutual core relationship with someone who gives them responsive, sensitive care, who will talk to them and encourage their development – but they don’t need to be with that person 24 hours a day.

Compared with this core relationship, childcare is relatively unimportant. That’s not to say it doesn’t matter, but it doesn’t matter as much as you may think. There’s a tendency to look back at the postwar generation of the 1950s, when most women stayed at home – alone – with their babies, as some kind of ideal. But historically it was a quirk not the norm.

Mothers have always worked and large families and manual toil meant that babies were looked after by older children and other relatives while mother got on with the washing or cleaning – just look at rural communities in poor countries today and you will see what I mean. Until the first world war, people quite low down the social scale had domestic servants, so there was always a pair of hands to take the baby.

Likewise, children today tend to spend their time with a number of different people. It’s a mistake to think a child is either an “at home child” or a “nursery child” or a “child-minded child”. The reality is that childcare is mainly a jigsaw puzzle. A child may be in nursery for a couple of days a week, then spend time with its grandmother or a friend.

If a child is at home with a mother and/or father who think it’s fun to be there and have a good social network, it’s fair to say that is the best environment we know for the first two years of life. But, on the evidence, there aren’t many mothers who want to be full time at home after the first few months, or fathers who are able to be.

The mental health of mothers who don’t go back to work is not as good as those who have at least some contact with the working world. The chances are that a woman who stays at home these days will be the only one in her street and that can be a lonely existence.

I have spent much of the past seven years co-directing the Families, Children and Childcare study, following 1,200 families and their childcare arrangements for children from birth to 4½. One thing we need to be clear about is that the vast majority of underones are not in formal childcare.

In America, a large number of very small children are in nursery, but in Britain only 8% of babies aged three months are in any form of childcare, which includes being looked after by a grandmother. At just under a year old, the proportion of babies in childcare is still less than half.

And is being looked after by grandma really “childcare” anyway? When is it a case of a grandmother wanting to spend time with her grand-children and when is it help for the mum? You can only really work that out by asking if it has been arranged so that the mother can go to work. So it’s difficult to be accurate about the actual number of hours.

The big misconception involves women and their jobs: while two-thirds of British women work, an amazingly small minority work full-time. People have a vision of babies being dropped off en masse at 7am and being picked up at 7pm, but that’s true of very few and they are not from underprivileged families. The babies who spend the longest hours in childcare are the children of the well-to-do, who use nannies.

Yes, of course, to be looked after by a not very qualified, not even very warm “carer” instead of a mother who would love to be with you is not a good deal. Yes, we need to know whether many hours spent in childcare at an early age produce less cooperative, less happy children later on. At the moment there’s a lot of evidence that it does and a lot of evidence that it doesn’t. Truthfully, we don’t know.

What seems clear is that we can’t provide the best childcare through private nurseries. You can’t fund it from what parents can afford to pay. Places such as Finland are brilliant because they pay for their childcare the way we still pay for education. It’s there for everybody.

It’s shameful that a lot of what we’re providing is not as good as we could make it. I’d like to see higher staff-child ratios that are real – often the ratios look fine on paper, but if you have one adult to three toddlers in a nursery, you have to remember that those adults have got to have a cup of coffee or lunch, and they’re sometimes going to be ill.

Nurseries must have key workers, responsible for particular children, who become the link to a child’s family; the one the child turns to if he has hurt himself or is unhappy or unwell. That is now the law but it does not work as well as it should.

What most of the families I talked to wanted was the best of both worlds: 12 months’ paid leave and then the right to work part-time. Some want to stay at home, some couldn’t wait to get back to work. There’s no right answer. It always depends on the family, the parent, the child. Government policy should provide choice.

The 100% accurate thing the Unicef report says is that attachment relationships are absolutely crucial. Fine. Let’s just remember: love isn’t 24/7 or nothing.

Penelope Leach’s Childcare Today: What We Know and What We Need to Know will be published by Polity next month.

Andrew Sullivan is away

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