Modern family life is changing - as the most recent census results in the Republic have shown. There are fewer conventional nuclear families - mother, father, children - more single people, more divorces, more cohabiting couples with one child and more adult offspring living at home - the 'Boomerang kids' who go back to live with ma and pa because buying or renting their own home is far beyond their means.
It's certainly a worry that for the generation in their 20s and 30s owning their own home seems a distant prospect. It will have to be addressed. Yet - is it always so bad when youngsters go back to live with their parents? If there is enough space in the home, and each generation is tolerant of the other, it can be an enriching experience.
It's not as though we're living in the era of John B Keane's Big Maggie, when parents could be tyrants about controlling the personal, economic and romantic lives of their grown offspring. Parents (and grandparents) have changed a lot over the past 40 years. Back in the time, fathers used to set a curfew time for daughters coming home at night, and mothers used to say, if a dress seemed somewhat skimpy, "you're not going out in that".
These days, I watch mothers ask their daughters' advice on what glammed-up confection they should wear for a night on the town and, with divorce increasing, the father may not be in the family home at all.
Parents now are not supposed to give any opinion whatsoever on the lifestyle of their grown offspring. Non-judgmentalism is the contemporary family protocol.
Yet as long as everyone gets along fairly reasonably, shared family homes can be perfectly sensible: better than having a lonely older generation rattling around in a house now beyond their needs, while a younger generation pays through the nose to rent, or even buy, a cramped single flat.
The posh classes always practiced a kind of generational sharing. Downton Abbey was quite an accurate picture of multi-generational living among the landed gentry - where the dowagers just downsized to a slightly smaller house on the estate. Keeping the family in some kind of proximity could also be a solution when a marriage is on the rocks. Divorce being so expensive and troublesome - and, my dear, the horror of dividing the estate - the current Duke and Duchess of Rutland, having decided that they were unhappily married, moved to different wings of the exquisite Belvoir Castle with their respective paramours: there is separation, but no disruption of property.
The recent census reveals the shifting patterns of family life in Ireland, but patterns of family life have always changed - and they were often influenced by economic factors. In the 1950s, there was tremendous concern about the reluctance of the Irish to marry - up to a quarter of Irish people were lifelong bachelors and spinsters, and there was some panicking reports suggesting that the Irish people might die out altogether in their native land, "like the Mayans".
Irish Protestants were as careful about committing to marriage as Irish Catholics. Perhaps the lack of divorce was also a deterrent - there was no get-out clause.
But money was the key factor - middle-class people didn't marry until they could afford to support a family. The youth movement of the 1960s and 1970s was an anti-family rebellion. Young people couldn't wait to get away from their parents and bedsitters and flatshares were easily available. The sexual revolution played a part; it was easier to sleep with a lover away from parental control. Nowadays, parents make allowances.
Feminism castigated the family, as "patriarchal oppression" and many on the left followed Engels's cynical analysis that the family was little more than a capitalist plot to ensure the legitimacy of offspring. Popular psychology disparaged the family as a wellspring of depression and schizophrenia, and the theme appeared in many novels and plays. Edna O'Brien said recently in an interview that she struggled against the tyranny of family and faith, as well as nationalism. Her early novels were centred on a young girl's bid to escape from the coercive influence of her family and make her own life.
Yet the family is a chameleon; where it is denounced or rejected, it responds by adjusting and changing shape. The family has changed shape, in Ireland and elsewhere, but remained resilient, retaining its influence and grasp on our lives, and with the development of ancestral research and DNA, kinship looms as large as ever.
Even same-sex marriage is a kind of triumph for the family. Some heterosexual men once envied homosexuals because family life didn't impinge - no clinging wives, inconvenient pregnancies, meddling mother-in-laws. Yet same-sex marriage has disclosed the number of gay people who want all the family baggage of spouses, pregnancies and in-laws.
More divorce and more single parents may put new strains on family life and an increase in marriage break-up does, palpably, lead to more loneliness in old age. The family has always been a battleground of wills, and of internecine conflicts and factionalism, and yet I'm impressed by how family-minded young people can be. When surveys ask young women who they most admire, their mother often comes top. Apparent decline in the 'nuclear family' doesn't necessarily mean family decline; the institution is an incorrigible survivor, impervious to extinction.