So imagine having to get to grips with the first hormonal upheavals of puberty not in the early teens, but as early as eight or nine years old. This is exactly what is happening in the United States, according to new research published by Professor Marcia Herman-Giddens of the University of North Carolina. Her studies have concentrated on girls, and she has found that children as young as eight are already showing the first signs of physical maturing.
While the average age for first menstruation (around twelve and a half for white girls, a year earlier for black girls) has remained the same for the past 50 years, girls still at primary school are developing breasts and growing pubic hair.
The model for all research on puberty is a comprehensive British report compiled in 1962 by Professor James Tanner; since then, no significant further studies have been carried out in this country. But Professor Herman- Giddens's report is adding to concerns that this issue is under-researched in the UK. There is, says Dr John Coleman, director of the Trust for the Study of Adolescence, anecdotal evidence to suggest that British girls too are reaching puberty significantly earlier. "Teachers are convinced that more girls are starting their periods while still at primary school. Scientists have different views. We urgently need some well-planned research."
THE EARLY onset of puberty can come as a shock to parents as well as to the girls themselves. "I felt sad for my little girl when she started her periods at 10," says Tina Senn. "I wasn't expecting it for another couple of years at least. We had not discussed it because I didn't think we needed to."
It was a difficult experience for both. "She couldn't believe she would be having to do this for years and burst into tears," says Mrs Senn. "And now I worry for her in other ways, too. I've tried to explain about sex to her and I worry that boys might try to take advantage. She may be developing a figure now, but she is just a little girl." She wonders if her younger daughter may have a similar experience. "But now I will start to discuss such things at an earlier age."
The Trust for the Study of Adolescence is discussing the possibility of a joint study with the Brook Advisory Centres and the Great Ormond Street Children's Hospital; funding has yet to be secured. A spokesperson for the Brook Advisory Centres also points to evidence from primary school teachers. "There are no statistics yet, but we feel something must be happening. We need to get information because sex education needs to be tailored to meet earlier needs. Services like ours might also need to be tailored, not because these children are having sex, but because they might need information."
THIS IS also one of the reasons why Dr Coleman of the TSA would like to see a comprehensive study carried out. "There are a number of different reasons why this information is important," he says. "There is the practical issue of sex education. If it is true that more girls are menstruating in primary school, it is clearly important to provide good quality information in primary schools - and parents need to be aware as well."
In terms of public policy, he says, such research could have a bearing on issues like the lowering of the age of consent. He also points to the increasing number of cases of precocious sexual behaviour. "There are alleged cases of rape amongst primary school children. These issues of criminal behaviour in relation to young people who are under the age of criminal responsibility are troublesome, and knowledge of developing trends would be helpful."
Plus, he adds, the issue is of great scientific interest, particularly to neuroendocrinologists who study the relationship between body functions and the nervous and hormonal systems.
"This is not just the science of physical development," he says. "It is a study of the impact of early maturing on young people. It is a very big issue, complicated by the fact that we have no way of measuring emotional maturity."
What research there is on children who develop early reveals that boys tend to feel positive about being taller, stronger and better at sports than their contemporaries. Girls have a more mixed reaction.
There are a number of theories about the reasons for a decline in the age of puberty. American scientists have put forward a variety of suggestions: better nutrition, fewer infectious diseases, greater exposure to hormones and chemicals which could trigger the body's own changes.
Professor Herman-Giddens, an adjunct associate professor at the University of North Carolina, believes that a variety of causes are probably influencing the children. But whatever the reasons, she says, there is cause for alarm.
"We don't know what nature intended, but I doubt it was breast growth at eight years old. We need more research to find out exactly what is happening." Early puberty is not always a positive experience, she says. "The girls are made fun of. Their parents didn't prepare them properly, and they are having feelings they are not prepared for."
She was surprised by the public response to her work. "Women who'd been early developers talked about how much they'd suffered. It was very poignant. One woman said she had been so glad to read the report because it made her feel she wasn't a freak."
The effect on boys of all this, she says, has not been considered at all. "No one has looked at the effect on boys of having girls around who are well developed, with breasts and periods, while the boys are still little-bitty children."
And, she says, there may be other implications. There is some evidence to show that oestrogen is linked to breast cancer; girls who grow breasts at seven or eight are exposed to oestrogen for more years than later developers.
Tina Senn mourns the loss of her daughter's childhood more than anything. "It's as though she's not a child any more," she says. "This is just the start of the whole adolescent thing. She shouldn't have to worry about that yet; she should have been a child for a few years longer."
What is puberty?
PUBERTY usually takes around two years, though there is now evidence to suggest that the process might be taking as much as a year longer. It is a complex phenomenon, involving not only sexual maturation but also physical growth and change and alteration in blood composition and hormonal functioning. Psychologically, it also involves the transition from childhood to adult status.
Girls start puberty approximately 18 months earlier than boys. The range of ages for starting puberty varies by as much as three or four years. For girls, the onset of puberty is characterised by physical changes such as breast growth and the appearance of pubic hair; boys also develop pubic and facial hair and their voices break. For girls, the onset of menstruation (the menarche) follows these earlier changes.
Starting periods is a powerful rite of passage on the female road to adulthood. In developed societies the age of the menarche has steadily declined over the years (it was around 15 at the turn of the century), but has remained stable for the past 20 to 30 years; this suggests that perhaps the minimum age of puberty has been reached.
"There is much debate on how to measure puberty," says Dr John Coleman of the TSA. "With girls you can simply ask when they started their periods, but with boys it is more difficult."