An American study of 4,000 children published this week has shown that what we've long been wringing our hands about with girls is also true of boys – children are entering puberty younger. There appears to be a racial factor, with Hispanic and white boys going through puberty at an average age of 10, and Afro-American boys showing signs at nine. Nearly one in 10 white boys and one in five black boys showed some signs of it at the age of six.
This sounds pretty early, and the first thing Dr Robert Scott-Jupp, consultant paediatrician at the Royal College of Paediatrics and Child Health, warns us is: don't take the toplines of a US study as your family medical dictionary. "I would be slightly alarmed if somebody read about this, noted that boys are going through puberty at six, and then didn't take their child to the doctor if he showed signs of puberty at that age. The child should definitely be seen by a paediatrician. It may turn out to be very early puberty, but that's very rare and it could be another condition causing it."
In the UK, there is no consensus that puberty is occurring earlier in boys; the range for the first signs is still taken as nine to 14. In girls, that range is eight to 14, and this has got earlier, although not by the margin you might imagine. In the 50s and 60s, the average age for first period was 13 and a half; now it's 12 and 11 months. Seven months is quite a long time when you're 12, I concede.
The racial element of the US study should also be viewed critically: Scott-Jupp continues: "Any study in the US that appears to identify differences between the races, the difference usually turns out to be that black families are poorer and more socially deprived."
But the fact remains that puberty is much easier to define in girls – it is the first period – and, possibly as a result of that, there have been many more studies, in which a much firmer conclusion has been reached. If it turned out in the long term that boys were also maturing faster, that would not come as a tremendous surprise.
So what could be causing it? What challenges does it throw up? How would a mature society deal with a physiological trend like this (let's assume for the sake of argument that we live in one of those)?
Pop psychology has posited the idea that girls' early menarche (first period) is associated with an absent or distant or in some way deficient father, but this seems to be a misreading of an aside in a study that found a link between obesity and early puberty. Diet is by far the most important factor – medics and psychotherapists both point to better nutrition being the definitive change in children over the past century. Phillip Hodson, fellow of the British Association for Counselling and Psychotherapy, says: "The best way not to go into puberty is starvation. Early puberty is about great nutrition, in the classic sense of getting access to good protein, good vitamins and minerals." He underlines that earlier puberty is often accompanied by a commensurate growth in height – this is particularly evident among Japanese girls over the past half century.
One other theory, "for which there is no evidence at all," Dr Scott-Jupp notes cheerfully, "is that more people being exposed to light for more hours of the day, in the form of artificial light, has an effect on brain chemistry." It makes your brain think you've been alive longer, I suppose, and that it's time you got married. This does seem a little far-fetched.
If diet were the cause, it would explain why Americans have seen results in boys faster than we have here; children there have a more calorific diet.
There are studies relating early periods to depression in adolescent girls, but the crucial anxiety hanging over the conversation is that, if kids are going to go through puberty earlier, does this mean they will become sexually active earlier?
Will their emotional maturity match their sexual development, and if it doesn't, is it realistic to expect that you can persuade them to hold off until it does? Dr Scott-Jupp reminds us, "There's a tendency to confuse puberty and adolescence. Adolescence follows puberty, they're not concurrent". Puberty is the physical change, adolescence the psychosocial transition, from childhood to adulthood. Just because a boy has developed pubic hair doesn't mean he's made the leap, as Hodson puts it, "Sorry to be vulgar, from Lego to legover."
Nevertheless, Hodson continues, "what we have to say is that if there were very early aspects of puberty occurring, you couldn't just assume that your six-year-old who has started showing signs of puberty would become the 10-year-old that you expect. You might therefore need a better set of disciplines around his life, because he might well have the rage and the strength and the sexuality, or flashes of those things, that a much older person might have."
The idea of hypersexualised 10-year-olds worries Hodson much less than the timeless experience that kids who are different get bullied, and having a faint moustache could be as devastating for your popularity as having horns and a tail, when you are 10. "The mercilessness of children is well known. The difficulties are compounded in the age of the social media, and the way in which people can be instantly, broadly vilified. But the anxieties of those with early puberty are dwarfed, to a degree, by the anxieties of those children who get left behind."
Dr Scott-Jupp, likewise, focuses on pragmatic considerations, above hell-in-a-handcart predictions of radically earlier sexual awakening. "It's a practical problem for young girls who start their periods while they're still at primary school age. They're not very well set up, there's not much privacy. There's also the important educational aspect, that girls need to be educated about puberty at an earlier age so they're not taken by surprise." But this is politically charged – you can't just shift the age at which education about puberty occurs; that leads inevitably to a conversation about sexual characteristics, and fairly inexorably to a conversation about sex. An NHS-funded website and App, Respect Yourself, was slated this week for considering questions like "what's the average age to lose your virginity" and "where can I buy a Karma Sutra?" appropriate to an audience of 13 and over (even though the answers – "17" and "a bookshop" – might not strike one as terribly controversial. I draw the reader's attention to another question in the FAQs: "can you have sex in the ear?" I don't think the compilation of these questions is liberal, or sexualising children, or whatever else it is supposed to be. I think it's comprised of questions they have genuinely been asked).
Alex Hooper-Hodson has just written The Boy Files, a boy's guide to puberty, which is out next year (he is also Phillip Hodson's son, by wild coincidence). He devotes a lot thought to persuading kids that this is a) nothing to be bullied about, and b) nothing to bully other people about, to which end, he says, "I try to get across that it's not about feeling like there's something wrong with you; it's not a disease. I'm trying to make it more interesting. So I've got little chapters comparing them to becoming superheroes. This is when you get your superpowers. It's when you get your muscles, which are like your superhuman abilities. Your voice breaks, which is like your sonic scream. And you get your emotions, which is like your telepathy." Sure. It's a bit optimistic, but nobody wants to depress them.
Signs of puberty are a pretty poor index of readiness for sexual relations, as I discovered this year through Save the Children's family planning campaign. In cultures where people still marry young – at 12, 13 or 14 – and have children as soon as they marry, the physical consequences are appalling: birth weights are pitiably low, mortality of mother and baby extremely high, and this is before problems like fistula manifest later on, in the mother's 20s, and see her socially ostracised for being incontinent or in some other way imperfect.
Nature tolerates a huge grey area, which could span a decade, when you have sexual traits but aren't ready for sex, or when you're ready for sex but aren't ready to procreate. Socially, I think we would all prefer it if there were no ambiguity or variation, if all the signs of puberty arrived at once, and they all arrived on everybody's 16th birthday. Unless we're prepared to seriously limit kids' portion sizes, we're going to have to get used to things being a little more complicated.
