Sandra Paterson: What happened to Itty Bitty Titty Committee

In the changing rooms at the hot-pools the other day, there was a girl of about 8 or 9 with pubic hair and more than just budding breasts. It was kind of weird, to say the least.

As the mother of a 6-year-old who still struggles to use a knife and fork properly, the possibility of trainer bras in two or three years is somewhat alarming.

Curious, I called Paul Hofman, an Auckland paediatric endocrinologist at the Starship children's hospital, to find out more about 21st century girls' hormones. (One of the great things about being a journalist is that you get to talk to experts without paying for their time.)

It turns out puberty at 8 is pretty normal. Clearly I have been working from home for too long and need to get out more.

Mr Hofman said that, although the age of first menstruation had stayed steady since the 1960s at around 12, the outward signs of puberty were now appearing earlier in some girls; and developing breasts and body hair at around 8 was not unusual.

"No way," said one girlfriend when we talked about it over coffee.

"I'm so glad I've only got sons," said the other.

The jury is still out as to why puberty is occurring earlier - it is more likely to be a complex mix of factors than any one in particular - although obesity is a prime suspect. Overweight girls tend to develop earlier than their slimmer counterparts, probably due to a hormone called leptin, secreted by fat cells, which triggers puberty.

It is still just a theory, however, and my primary-school teacher friend says plenty of the pupils getting their first period in what used to be called Standard Four are skinny wee things.

Other theories include pesticides and hormones in the environment; and even the structure of the family. Several reliable studies show that girls who have close relationships with their biological fathers during the first five years of life start puberty later than girls raised in fatherless homes or by stepfathers.

Researchers speculate that exposure to the scent of unrelated adult men accelerates puberty, while the scent of a biological father inhibits it - a phenomenon which occurs in other mammals.

Reassuringly, however, boobs and body hair aged 8, and periods at 10, while considered normal, is still the exception rather than the rule. The average girl will starts developing at around 10 or 11, with menstruation at 12 or 13.

And of course, as Mr Hofman pointed out, there are still plenty of girls who are late developers. (At the risk of revealing too much information, some schoolfriends and I at one stage formed the IBTC - the Itty Bitty Titty Committee. From which we eventually graduated, but not without much angst over the lateness of it all.)

"It's true some girls are starting to show physical development earlier than in previous years," said Mr Hofman.

"There are sub-populations, if you like, at both ends of the scale.

"But what is probably more significant - and more obvious - is that young girls are now pretty precocious. They are so much more socially aware."

You can say that again. For some time now, childhood has been getting shorter and shorter. Everywhere a young girl looks - magazines, billboards, music videos - the message is you have to be sexy to be cool.

From the time they can walk, there's play make-up, Barbies with boyfriends; and sophisticated clothes which would look great on a woman but silly on a 5-year-old and plain slutty on a 12-year-old.

My next-door neighbour told me recently how her primary-aged granddaughter was "upset and stressed" because she was uncertain what to wear to a birthday party, worried she would not look "cool enough".

Overseas, 10-year-olds in Korea are seeking facial plastic surgery, often encouraged by their parents; and American officials warned this week of girls as young as 9 using illegal steroids to get more curvy, toned-looking bodies, now that the waiflike supermodel look of the 1990s has given way to a fuller but toned Jennifer Lopez look. How sad.

Some doctors say the way young children are bombarded with sexual imagery could be contributing to the earlier onset of puberty. There does not appear to be data to support the idea, but common sense would suggest it is likely.

All in all, it is enough to make us want to take our daughters and go live with Anahera Van Duin and the 19 children living in a remote community up north. The Herald on Sunday described how they had no power or running water and no formal schooling, but lots of freedom and simplicity and love.

Ah yes, the slightly hippy side of me finds the idea quite appealing. So does the lock-the-doors-when-they-turn-13 side.

But a solo dad friend of mine reminded me recently that the best thing we can do for our daughters is teach them the truth - it's not what you look like that counts - and to think critically. To equip rather than over-protect, as we mothers are prone to doing. It is good advice.

Nonetheless, I'm still hoping for breasts at 13 in this house, not at 8.