Why The Testosterone Surge in Young Boys is a Myth (and what really causes their behaviour to change!)

It’s almost guaranteed to pop up on every parenting related discussion forum, website or chat room you visit.

“Did you know that young boys, around 3, 4 or 5 have a HUGE surge of testosterone? That’s why their behaviour is so difficult at this age”

Seems like a great explanation for the difficult behaviour many parents face at this age doesn’t it?


As a mother of three boys I know what it’s like (but then as a mother of a girl I know she can behave exactly the same). This information seems to trace back to one source,  the book ‘Raising Boys’ by Steve Biddulph. A perpetual bestseller, treasured by hundreds of thousands (millions?) of parents around the world.

Despite the popularity of this information however, I can find no evidence that a testosterone surge in young boys exists, at least not according to my extensive research over the last eight or so years. I’d be happy to proven wrong if anyone can point me elsewhere however? Is it possible that Biddulph’s source was wrong?

It’s something I’ve always felt a little uncomfortable about so I started searching for evidence when my own boys were young (and any unwanted behaviour commonly resulted in people telling me “oh that’s just their testosterone surge”). In my opinion, the idea is right up there with Santa, the Tooth Fairy and the Easter Bunny, beloved statements borne out of our need to pathologise normal child behaviour and remove us of responsibility. Could it be that thousands of parents are being misled about this testosterone surge on a daily basis? Blaming their child’s behaviour on a hormone spike that doesn’t exist?

I’m by no means the only one questioning the existence of the childhood testosterone surge, check out these blogs and discussions too, who all came to the same conclusion as me:






This is an except from a book entitled ‘Gender Equity in the Early Years’ by Naima brown:


Finally here’s a great presentation from a doctor specialising in adolescent medicine who is quick to dismiss the idea that a pre-pubertal testosterone surge exists (check out slide 12):


What Really Happens to Testosterone Levels in Childhood?

Testosterone is an important androgen, or what we more commonly know as sex, hormone produced by both males (in the testes and adrenal glands) and females (in the ovaries and adrenal glands). It is an important hormone for both genders, playing a vital role in bone density and muscle mass, as well as the more obvious development of sexual characteristics.

Immediately after birth the testosterone levels of boy babies are around around 120ng/dl – around half the level of an adult male. They then rise fairly significantly to around 260ng/dl between the second and third month , but then begin to fall very quickly after. By the time the baby boy is 6 months old research shows that his testosterone levels will be extremely low where they will remain until the boy approaches puberty.

The following table shows the changes in testosterone levels as puberty approaches:


I cannot find a single reference to a surge in testosterone in any clinical trial data or medical text book beyond the post birth spike, and believe me I have looked – hard. The only testosterone spurt that is well documented is the one that occurs in the first few months of life.

 Research in 2002 indicates that the famed testosterone surge does not exist post 6 years, with findings showing that:

” Statistical analysis did not prove changes in salivary testosterone concentrations in the preadolescent period of life, with an exception of the insignificant fall at the age of 7 years, and an insignificant rise at the age of 9 years in girls.”

Which led the researchers to conclude that:

“Generally it can be concluded, that salivary testosterone levels in our pre-pubertal subjects remained stable.”

Unfortunately there seems to be no research showing levels between the first few months and this stage, but all lab normal ranges I could find for these age ranges fail to show a spurt. Medical books often contain graphics showing the changes in testosterone levels by age during childhood that look like this however (you’ll note how flat the pre-pubertal section is):


Could there be a danger in attributing a young boy’s behaviour to a testosterone spurt if it does not exist? I think so. I worry that their real needs may not be met if the parent feels that their behaviour is transient and due purely to biology.

What’s Really up With a Four Year Old Boy’s Behaviour Then?

In short – Us, me, you, parents, adults, society……..

We don’t really get normal little boy behaviour, which is strange given that around half of all adults have been one. Little boys (and that is what a four year old is) need to play, play, play, play, play and play some more. They need open space, nature, air. They need trees to climb, balls to kick, mud to squelch, frisbees to throw. They need to be allowed to use their amazing imaginations and explore the world with their whole bodies.

Instead they get school, schedules, strict rules, told to sit still, cooped up inside, taught to read and write, not speak unless they raise their hand and screen time.

These things and four year old boys don’t mix. That’s not the boy child’s fault, it’s totally ours for not understanding or meeting their needs.

So what happens? Frustration and a heck of a lot of it. That can either get internalised (anxiety, depression, insular withdrawn behaviour, sulks and the like), but in the case of most four year old boys it gets externalised (kicking, biting, hitting, throwing, punching, yelling, screaming, whining – you know the ones I mean…) which actually in a way is more healthy than internalising the behaviours, but definitely not socially acceptable.

This frustration has nothing to do with testosterone, lets not blame the failings of modern society onto a chemical. The thing is if we do blame it on testosterone we can appease our conscience, we think “oh it’s OK, little Johnny is just having a testosterone spurt” but that’s dangerous because it stops us from dealing with the REAL issue, which is why I get so very mad at how large and out of control this myth has become.

For those interested in the science and effect of gender on parenting I’d recommend THIS BOOK.


p.s: Come and chat with me on FacebookTwitter and Instagram You can also sign up for my free weekly parenting newsletter HERE.


Published by SarahOckwell-Smith

Sarah Ockwell-Smith, Parenting author and mother to four.

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