THIS WEEK saw the seventh birthday of David Cameron's eldest child. Today is the ninth birthday of the eldest son of Nick Clegg, the deputy prime minister. Quite properly, these were private events: in an ideal world, the children of the famous or powerful would not even be pictured in the press. But the simple fact that the two most senior figures in the government have such young children is pretty striking, especially when you do the sums and realise that among all the children of the three main party leaders, plus key members of the coalition inner circle like George Osborne, Steve Hilton, Michael Gove or Danny Alexander, not one is older than nine.

This must be pretty unusual in the modern history of the country. Part of the cause is the youth of the current crop of top politicians: many of whom are in their early 40s. There is also the trend for middle class men to have babies later, into their 40s. In this week's print column, I set out to ponder whether this profusion of small children has an impact on the politicians who run this country (beyond inducing chronic exhaustion). It does not do to be too deterministic about these things. But after talking to a range of people who know the three party leaders, I found a pretty firm consensus that the political culture of Britain, at its highest levels, is being changed by this daily exposure to very small people. Here is the column:

THEY begin—painfully—with Tinky Winky and Igglepiggle. They end somewhere near Narnia, or Hogwarts. For millions of middle-class Britons they are perhaps best described as the Gruffalo years: an innocent interlude stretching from birth to a child's ninth birthday or so. Barring tragedies, children in these years inhabit a sheltered, more benign world—and fortunate parents enjoy visiting rights. With luck, outside horrors can be kept at bay. Parents are not yet embarrassing, and a bedtime book is still a treat: the Gruffalo, a dimwitted monster, is a particular British hit. It is an age before tests turn brutal, when a child's life still shines with potential. Time enough for failure later.

A striking number of senior politicians live, at least part-time, in the world of the really young. David Cameron, the prime minister, his Liberal Democrat deputy Nick Clegg and the Labour leader, Ed Miliband, all have infants under two years old, and none has a child older than nine. Members of the coalition inner circle such as George Osborne, the chancellor of the exchequer; Steve Hilton, the Downing Street director of strategy; Michael Gove, the education secretary; and Danny Alexander, the Lib Dem chief secretary to the Treasury have families just as young.

The nappy-changing diligence of Mr Cameron, Mr Clegg and Mr Miliband should not be exaggerated. All three work ferocious hours and can afford child care. Mr Cameron has family money; Mr Clegg and Mr Miliband have high-flying lawyers as partners. But all three try to carve out time for their children. Mr Cameron's family lives above the shop in Downing Street. Mr Clegg works late but walks his two older sons to school when he can. Mr Miliband holds many meetings at his north London home. This is both engaging (as when the Labour leader talks strategy with a baby on his knee), and time-consuming (as when his toddler swiped guests' mobile phones at a recent gathering).

Part of the explanation is the youth of Britain's rulers: Mr Cameron was the youngest prime minister to take office in nearly two centuries; the main party leaders are in their early 40s. The professional middle classes as a whole are having children later. The child-bearing trend began in 2000, when Tony Blair sired the first baby born to a serving prime minister in more than 150 years. But he also had teenage children, so had been dunked in the stormier waters of adolescence. A turning point came with Gordon Brown's coronation as Labour leader in 2007. Though in his 50s, Mr Brown had two very young sons (his first child died shortly after her birth in 2001). Suddenly all three party leaders were new parents. What is more, the younger men in Mr Brown's cabinet were keen to be active fathers, adds a figure close to Mr Brown and Mr Miliband. It was “a massive cultural change compared to ten years before”.

A centrist Conservative MP makes a matching observation about the youthful circle around Mr Cameron. The Tory party of ten years ago was slow to grasp the importance of social policies. For today's leadership, children are the “ultimate nudge”, he says, a reference to the Cameron camp's zeal for “nudging” people into changing behaviour. At its simplest, parenthood exposes even the affluent middle classes to public services, from hospitals to day-care centres or libraries. Despite (mostly) shielding their children from press attention, all three current party leaders claim inside knowledge of the National Health Service and the strains of balancing work and family life.

Launching a vast reform of the NHS on January 17th, Mr Cameron—as often before—cited his biography as proof of his good faith, praising the doctors who cared for his severely disabled eldest son (who died aged six in 2009), the maternity nurses who recently helped deliver his baby daughter and the teachers “currently inspiring” his two other children at primary school. On the same day, Mr Clegg vowed to help fathers be more “hands-on” with their children, whether by taking more parental leave or seeking flexible working hours. On January 15th Mr Miliband apologised for the previous Labour government's embrace of labour laws that had squeezed “time with our families”.

With close advisers, the Labour leader has pondered the politics of parenthood: does it make people more conservative, by which he means competitive and sharp-elbowed? Or perhaps (Mr Miliband hopes) parenthood induces empathy and trust, as even flinty individualists find themselves grateful to nannies, doctors or the BBC, with its wholesome children's programmes.

Smugger but wiser

Daily exposure to innocence matters. Parenthood can lead to smugness, but also humility. All parents soon realise how much of child-rearing is improvisation, tempered by exhaustion. Political parents learn that ideology is not everything. The coalition leaders use state primary schools. But in interviews, Mr Clegg (who like Mr Cameron was privately educated) has reserved the right to send his boys to a fee-paying secondary school, saying he is a father before he is a politician. Though the three are social liberals, parenthood has exposed flashes of conservative anxiety. Mr Cameron frets about rude pop lyrics and “sexy” clothes aimed at children. Mr Miliband says this is the first time in 100 years that parents fear the next generation will be worse off.

The importance of the Gruffalo years unites all three parties. The Tory-Lib Dem coalition has published reports from two Labour MPs, Frank Field and—most recently—Graham Allen, urging “early intervention” to help deprived kids from birth. Some Tory ministers grumble that 16-to-25-year-olds have been a bit forgotten by the coalition. That may be right, yet on balance young parenthood is healthy for Britain's rulers. The world looks at once kindlier and more fragile with small children in it, and essentially optimistic. In these austere times, that is a source of strength.