They're not girls, not yet women...
What parents should do when their daughters grow up suddenly. Cassandra Jardine reports
When I was 12, my pottery teacher invited me to a party. For a year or more I had been learning to throw pots at his studio and I was flattered to be treated as a grown-up. Rather to my annoyance, my elder sister decided to chaperone me -- rightly so, for the party turned out to be an orgy.
Swiftly backing me out through the door, she asked the host why on earth he had invited someone so young. "I thought she was 18," he replied.
It was an understandable mistake. In the late 60s, not many girls reached their full height before they left primary school, or had other misleadingly adult paraphernalia.
Many more of them were like my tiny Japanese best friend who still shopped for children's shoes.
Nowadays, she would be the exception and I would no longer enjoy, even briefly, the compensation of being useful to the netball team. For girls in Ireland, and throughout the developed world, have been reaching puberty at a younger and younger age.
The latest results among a group of 1,000 Danish children, in research conducted by Professor Anders Juul of Copenhagen University, a paediatric endocrinologist, showed that between 1991 and 2006 the average age of breast development -- the first sign of impending puberty in girls -- has come down from 10.88 to 9.86 years.
For every worried 14-year-old who is still padding out her bra with socks, there is now an eight-year-old who is being taken, red-faced, to the lingerie department fitting room.
These children may have been tottering around like Suri Cruise in high heels from the age of three. They could be watching unsuitable programmes on television. But becoming physically mature at an early age is confusing, both for children and their parents.
"Young children should be concentrating on friendship and education," says educational psychologist Madelene Portwood. "This adds to the pressure on them to behave like adults."
Early puberty is a physiological phenomenon, with important emotional implications. These girls are towering over boys of their own age because, for girls, the growth spurt and development of breasts come first; periods come later.
With boys, it is the other way round: their genitalia and sweaty armpits develop before their height shoots up. The last stage of the process, when they are able to signal their manliness, comes when their voices break.
All these markers have been occurring steadily earlier for both boys and girls, but recent changes have been dramatic.
Parents of girls in Victorian times found it easier to prevent them becoming mothers at the age of 12, because they were hitting puberty at 15. Girls are now having their first periods aged 13.1 years.
Over the past 15 years, girls have started having periods three months earlier; in the same time span boys' development has dropped by a similar amount to 11.66 years.
Happily, the earlier age of puberty is not, in itself, a reason to panic, says Professor David Bainbridge, a zoologist and author of Teenagers: A Natural History.
"It is the result of a better diet. Puberty is triggered by GnRH (gonadotrophin-releasing hormone). This affects the pituitary gland, which releases neurotransmitters acting directly on the ovaries or testicles."
It seems weight is our trigger, although genes play a part, too. Better nourished, taller and heavier, there seems to be a tipping point at which the hormonal changes begin.
Encouragingly, there seems to be an age below which maturity does not descend. In the Netherlands the age of first periods in girls has reached a plateau at around 13 years. That is likely to happen here, too.
The more worrying decrease in age is related specifically to the development of breasts in girls, which can now occur long before puberty. This could be linked to the increase in genital disorders in boys.
"Six per cent of baby boys have undescended testicles, 1pc have deformed penises," says Professor Richard Sharpe of the Medical Research Council's Human Reproductive Sciences Unit in Edinburgh.
"One in six men now has a low sperm count, and testicular cancer is doubling every 20 years. I'm more convinced that these problems, and early breast development, have their origins early in life. The problem is assigning a cause."
Various potential villains are being investigated. The pollution of drinking water by oestrogens derived from the contraceptive pill and HRT has been known for 20 years to cause hermaphroditism in fish.
Naturally occurring plant oestrogens could also be responsible, among them tea-tree oil used in anti-nit treatments.
The finger has also been pointed at parabens -- preservatives used in shampoos and sun tan lotions.
Bisphenol A, a component used in the lining of tin cans and plastic bottles, is another possible culprit. Sharpe, however, is more concerned about phthalates, chemicals used to make plastic soft and transparent.
Whatever is causing premature breast development, more and more children are suffering the embarrassment that comes with looking like adults while they are still at primary school.
Parents can try to delay the onset of puberty by helping children stay slim, but there will always be some who develop young.
While physical changes can be premature, the brain seems stuck on an immutable development timetable.
"The distinctive brain changes of adolescence are not driven by hormones, they are an independent process," says Prof Bainbridge.
"The quest for autonomy, more complex thought process and the ability to think about other people: these start aged 12-14, as they always did. Whereas these used to occur before puberty, now they come afterwards."
Children in adult bodies find it confusing. And the pressures now to act adult are greater.
"My approach to working with children has changed," says Portwood, "because not only are they physically sexualised earlier, emotionally they are more vulnerable than they were 20 years ago. When they used to stick with the same group of friends from nursery to secondary school, they had more support.
"Now they move more, and the extended family is not often around, we are seeing an increasing incidence of mental health issues, including anorexia and teen suicide."
Most primary schools now have sanitary bins in girls' lavatories. But that is not enough. They also need school counsellors, says Portwood, to help children confused by looking older than they are.
Parents, too, should be careful not to treat them as teenagers.
"They need to look at their emotional, not their physical, development. Children of 10, 11 and 12 may look grown-up, but they shouldn't be treated as young adults or allowed to wear adult clothes."
Or, indeed, go to orgies.