The subtle signs your child is going through early puberty.

If you’re the parent of a young boy, you might not want to hear this. But you can expect the first signs of puberty to kick in around age eight.

Researchers at The Royal Children’s Hospital in Melbourne have been studying an early phase of puberty, known as adrenarche. It’s a surge in androgens, which are the male hormone, and it hits both boys and girls when they’re eight or nine.

“There’s no physical side of it, so there’s no hair or anything like that,” explains Amanda Dunn, author of The New Puberty. “It’s just a hormonal surge. But it’s a kind of curtain-raiser for puberty. What the research is showing is that boys seem to be more affected by it than girls. It can have quite a big impact on kids’ emotional lives and also on their relationships.”

Dunn has spoken to teachers who say they often see a change in boys around Year Three or Year Four.

“They’ll notice that boys who previously weren’t very emotional seem to burst into tears more often or more readily than they used to, or their friendship groups might fracture a little bit and rearrange themselves.”

Boys might get emotional if one of their friends is mean to them, or they feel like they’re being left out.

“It’s the usual things that would upset an eight-year-old," Dunn said. "But where they might have just brushed them off, now there’ll be tears instead, or what seems like an unusually emotional response.”

Dunn thinks parents should be prepared for things to get “a little bit turbulent”. “Obviously, it goes without saying that you don’t want to be saying things like, ‘Don’t be a sook,’” she adds. “There may be a very good biological, hormonal reason why they’re more emotional than they used to be.”

With puberty hitting Australian kids earlier than it used to – something that’s particularly noticeable in girls – Dunn thinks that schools should teach sex education around the middle of primary school. There, kids can learn what changes to expect.

“If we leave it until Year Six, which is what a lot of schools do, more than half the girls have already got their period. And getting your period is a late stage in puberty, not an early stage. It’s too late by then.”

Dunn says she can understand that some parents might not want to face the thought of their kids beginning puberty at age eight.

“It can make you feel a bit melancholy, because you think, ‘Oh, do we really have to deal with this at this age?’ But increasingly, the research is saying, ‘Well, yes we do.’”

She says burying our heads in the sand isn’t going to work. “It’s not a helpful response to these kids or ourselves. We’re not going to turn back the clock on this anytime soon, so instead we have to get better at talking to kids about it.”