The difficulties of being a teenager in the 21st century were also laid bare, with three in five parents admitting their child suffered from 'anxiety'.

London - Tonight our daughter returns from university after her first year. The house will sing (and shout) again. I'll cook feasts while she watches American sitcoms. There will be mother and daughter flare-ups, ending in the fondest of tears and tightest of hugs. After she went off, my husband and I could work and go out more without guilt and rediscovered each other in ways that aren't possible when your focus is on raising kids. None of that filled the emptiness she had left behind. You never get used to it.

My friend, the novelist and journalist Nicci Gerrard, whose four children are now all away, describes how for home-alone parents “life suddenly feels the wrong shape”. I still remember the sorrowful months following the flight of our son. He couldn't wait to go off to Edinburgh University; I couldn't bear to let him go. When he asked if he could move back in with us in his mid-twenties, happiness, like sunlight, illumed our lives once more.

According to the Office for National Statistics, adult children are moving back in with parents in numbers not seen before. In 1997, one in four men and one in seven women were living with mum and dad; in 2011 the figures are 20 percent higher. Pew research indicates the same trend in the US and finds the arrangement is working well for most. In Canada, according to some analysts, 51 percent of 20- to 29-year-olds are back in their old bedrooms, probably secretly cuddling their old teddies. One assumes it is happening because of the global economic crises, spiralling costs of housing and destabilising fears - the lack of confidence that things will get better. Whatever the causes are of the internal re-migration, I don't see why it's a problem or something to be ashamed of. In some cases maybe the kids are ripping off the parents or becoming a burden, but most who have to or choose to share the family house are not “scroungers” or “losers”.

Okay, one doesn't want a nation full of spoilt, indolent “bamboccioni”, the Italian for “big babies”, who find it impossible to be weaned off Mama's love and pasta. But the cold attitudes one finds in our society do make one ask why people have children if they want them to go off after the age of 18. Why does parenting have to turn heartless after that?

Regrouping, if and when it happens, is hard but it renews bonds, invigorates, challenges us to communicate better, to be less selfish. We are all given a second life. When it works, everyone's a winner. Even if it proves to be a nightmare, we owe our children shelter and understanding.

Most humans through history have lived with those closest to them. Independence and individual responsibility do not necessarily signal adulthood - but family mutuality does. You can see how it works among South Asians, Arabs, Africans, the Spanish, Chinese and Vietnamese. Unhappily those good values are vulnerable in a fast modernising, atomising world.

A Hindu family I know lives in a leafy London suburb in three, vast attached houses. Their extended family totals 28 adults and children. They run a big food business and have an intricate chart detailing who does what when at home and at their various outlets. Couples have their own space and some privacy but are part of the whole. Childcare and management comes free, though now they get in paid help for the elderly.

I feel very jealous when I visit this merry clan - my own birth family was grotesquely dysfunctional and I was glad to be rid of most of them. Then I was wild and terrifyingly free of attachment, never had family security, didn't care for it. Now I think it is the most valuable gift we humans have and can give. And it could save our futures avers John Graham, an American business professor: “The cure for our current demographic disaster is the pooling of resources across generations. The idea of the nuclear family is obsolete.”

That pooling can't happen if we stigmatise the “boomerang” children and see them as parasites or failures. And they too will have to treat oldies with much greater respect. Too many spoilt brats whinge too much about privileged baby boomers and their alleged “betrayals” of younger generations. Such ingratitude. Now that these young adults need us as much as we need them, let them show more appreciation when they come to stay. And no more ugly talk about burdens. We really have to be in this together and with good heart.

Over the next months unwashed clothes and dishes will pile up and everything will once again revolve around the one who has been away. Her dad will bend to her every whim and I will turn into a horrid disciplinarian. But intimations of mortality will be swept aside by the high drama of youth and imaginings of the future full of plump possibilities. And then, as the leaves turn to brown, she will be gone again. I will feel colder and older, closer to death than life. I know many parents will understand what I mean. If only our adult children also understood what they bring us and how we love having them back. - The Independent