Ep 163: Forget Hormones! What’s Going On Inside the Teen Brain?

Episode Summary

Dr. Sarah McKay, author of The Women’s Brain Book, demystifies the research on the brain–the difference between males and females, the impact of hormones, and why the teenage years are such an exciting time for the brain.

Show NotesInterview TranscriptGuest Bio

Full Show Notes

When our middle or high schoolers are driving us up the wall, we often attribute their wacky behavior to hormones. They weren’t this crazy when they were younger, and we pray they won’t be this unpredictable as adults, so we assume it must be those teenage chemicals in their brains making them act up. It’s just a biological process, and there’s nothing we can do…right?

But attributing all of our teens’ behavior to hormones can bring up some complicated questions for parents. Like, with everything going on in her brain already, would it be wise to put my daughter on birth control? Or, is it normal, hormonal, behavior that keeps my teenager out late, causes him to drive like a maniac? What if there are other factors to consider when pondering these questions that can make things a little clearer for parents?

To find out, we’re talking to Dr. Sarah McKay, renowned neuroscientist, to find out what role hormones really play in teen’s development…and what popular ideas are actually misconceptions! Dr. McKay is an Oxford educated doctor with years of experience researching brian science. Finding herself intrigued by outdated or misconstrued ideas about the female mind, she decided to write The Women’s Brain Book, a comprehensive look at the development of women’s neural pathways.  

In this week’s episode, Dr. McKay’s demystifying the role of hormones during puberty–and explaining why we give them too much weight. Plus, we’re discussing the specific brain changes our pubescent kids are experiencing, and getting into how gender stereotypes seep into what should be purely scientific perspectives of puberty.

The Truth About Hormones

Although we often think of puberty as being absolutely characterized by changes in hormones, the truth is a little more complicated, says Dr. McKay. Although teens are experiencing a switch up of hormonal activity during this tumultuous period, it’s not just these hormones that are making them act up!

In the episode, Dr. McKay elaborates on how teens’ brains are constantly receiving messages from everything they do–every muscle they move, every bite they eat, or even the temperature of their body! This means that beyond just the new, puberty- induced hormonal changes going on in teen’s brains, their environment and contextual elements are constantly contributing to mood swings, anger, sadness, discomfort, etc! Puberty hormones simply dial up or dial down the emotional effects of these external influences.

By pinning everything on hormones, Dr. McKay thinks we might be furthering a particular narrative about emotion–especially for girls and women! When we chalk up mood swings or discontentment to hormonal activity, we’re only starting the common, offensive misconception that when a woman isn’t happy, it must be because it’s her “time of the month”. It can lead to the idea that a woman’s anger or concern is just her being “hysterical” or overreacting due to her, well, being a woman! As Dr. McKay emphasizes in the episode, we would rather our kids have a more sophisticated understanding of female emotion than this!

In our interview,  Dr. McKay talks at length about the birth control pill and whether or not the hormonal effects are important to consider for your own teen. To continue our discussion of puberty struggles specific to the female, we’re also breaking down how our society’s commonly held beliefs about gender affect our perspectives when it comes to puberty.

How Our Idea of Gender is Too Generalized

There are a lot of gendered ideas about puberty floating around, and Dr. McKay is here to help separate fact from fiction. To start, she tackles differences between male and female brain development when it comes to mathematical thinking. Many people think that boys are able to configure complicated mathematical concepts before young women, like being able to rotate a 3D object in their minds. 

Dr. McKay explains that while there may appear to be some truth to the idea if you’re looking at overall averages, it’s not necessarily reflected when studied on a case by case basis. Plus, the difference might not be a result of brain development. If we were examining a brain, Dr. McKay explains, there would be nothing indicating whether it was male or female, as the two are nearly identical. This means it’s possible that learning differences between men and women are from the way we teach them!

Dr. McKay confirms that there are some differences along gender lines when it comes to the rate of mood disorders among adolescents–but a lot of this comes from gender roles. For example, young women are more likely to talk to others about the way they’re feeling, but it can cause them to ruminate on certain problems longer than they should. This can cause depressive or anxious thoughts to become more and more ingrained until young women find themselves with a diagnosable mood disorder. Men are less likely to confide in others because they aren’t encouraged to! Instead, they’re more likely to develop anger management issues or alcoholism as a result of repression, Dr. McKay explains.

If your teen develops physically earlier or later than their peers, this can also be a gendered issue encompassing mental health, says Dr. MacKay. Young women who develop early tend to be treated as outsiders, leading them to develop anxiety or other mood disorders. Men who develop later are often looked down upon or treated as “wimpy,” leading them down a similar road, Dr. McKay says.

Dr. Mckay talks even further about gender and puberty in our interview, and brings up some seriously surprising points! In the episode, we’re also covering why adolescence is such a critical period for learning and growing, even if we don’t think of it that way.

Breaking Down the Adolescent Brain

Dr. McKay explains that there are two times when human brains are the most posed for learning–the toddler years and the teenage years! Two and three year old brains are adjusting to learn talking and walking, while the teenage brain is ripe for learning history, math, science and English as well as empathy and emotional regulation. In our discussion we talk about how we often underestimate teens’ brain power, when we should really be cheering them on!

If you’re wondering why teens can be so reactive during this period, it’s because their neural pathways are still developing, and the emotionally reactive parts are the ones that develop first! Dr. Mckay explains how more logical responses tend to arrive in a few years, when teens have refined their reactive thinking and strengthened the pathways that lead to rational responses.

One thing parents should look out for in growing teens is what Dr. McKay calls cognitive reappraisal. This is a thought process that is common for developing teenage brains that often leads to social anxiety, insecurity, or fear of rejection. Dr. McKay explains this concept further in our interview and shares how it might be affecting your teen.

In the Episode…

Dr. McKay’s bountiful experience and wisdom shines through in our interview. On top of the topics discussed above, we talk about:

  • Why puberty is starting younger and younger
  • How to use stealth to teach kids lessons
  • Why we should rethink teen risk-taking
  • How body temperature affects our mood

Thanks for listening! I had a blast learning all about the brain from Dr. McKay and hope you did too. Don’t forget to share and subscribe and we’ll see you next week!

Complete Interview Transcript

Andy: Wow. Alright. You clearly did a lot of work on this book. You’ve been researching this topic forever. And you said you got into this from an article that you were writing on brain fog. Talk to me about the story behind this. How did this whole thing start, this interest of yours?

Dr. McKay: Yeah, well, I’ve been working in some form or another within neuroscience, studying, teaching, researching neuroscience, essentially my whole career. But neuroscience is this enormous topic. It’s broad, it’s deep, it’s rich, it’s complex. And I have to confess, up until the time I started writing the book, I hadn’t really started to explore this concept of the so-called, and I don’t really like the title, the female brain. Rather taking a look at brain biology through the lens of being a girl and a woman and vice versa, looking at my life as a female through the lens of neurobiology. That didn’t really come about at all, despite having worked in neuroscience for 25 years.

Dr. McKay: But the idea really came about, as you say, I was approached by a book publisher, by a very charismatic woman, Jeanne Rykmans, who went on to become my agent, who said, “Do you want to write a book?” And I said, “No, not really.” And she said, “Oh, go on. Let’s meet for a cup of coffee and a chat.” Because I knew that if I was going to write a book, it would have to be about something I didn’t know a lot about, that I was really super curious, and I just didn’t want to write about things I already knew. I wanted to research and get my teeth into a topic. And so we literally, we’re sitting over coffee, chatting, and she said, “Well, tell me what you’ve written before that has really resonated with an audience.” And it was this previous article I’d written for the ABC here in Australia, which is kind of like the BBC in the UK, on menopause and brain fog and why many women think that they are developing dementia when they experience some of this brain fog through the menopause.

Dr. McKay: And she said, “Well, write a book on menopause.” And I was like, “Well, I’m in my early forties. That’s a bit weird. My mom did that once. No, thanks.” And then she said something about baby brain and pregnancy and I roundly dismissed that idea. I’m a New Zealander. I grew up in New Zealand and we’re very pragmatic and things like baby brain don’t exist there. Pull our socks up and get on with things. But as I thought neuroscience, menopause, neuroscience, pregnancy, I thought, “You know what, there’s perhaps something in there around taking a look at the female lifespan, taking a womb to tomb look at aspects of the female lifespan through the lens of neuroscience.” And so I very, very quickly wrote a chapter outline, which of course included infancy and childhood and puberty and the teenage years and so on. And that’s kind of how the book came about. And for me really, it was just this fantastic journey of research and discovery.

Andy: Okay. I thought there were some really interesting things on puberty. But you looked at a lot of research. Is puberty starting at younger ages now? I hear people talking about this a lot, how it seems like every year it’s getting younger, younger age, the age of puberty. What’s the research show about that?

Dr. McKay: That’s a really, really interesting question. And I think you’re always going to read about the startling outliers in any life event. You’re always going to read about the multiple births. Or you’re always going to read about the poor little girl who gets taken shopping for a bra for the first time when she’s eight years old. You always hear about the extremes and we have really, really good data on this. Now, it does vary slightly in different countries around the world. But largely speaking, when we think about puberty starting in girls, the age, that if we talk about what we call menarche, which is the age at which a girl gets her first period, that has dropped somewhat, but not perhaps as much as people may think, over the last couple of hundred years. When we kind of go back a couple of hundred years, girls were probably getting their first period at maybe 14, 15.

Dr. McKay: Now it’s much more likely to be around 11 and 12. And it’s been around those ages since about the 1950s or 1960s. It hasn’t changed that much. And we think a lot of that change was around just generalized public health, better nutrition, better awareness of disease, better awareness of general health and well-being. And that’s kind of brought that age of menarche down to a quite perhaps a healthy normal. What we have started to see in some parts of the world is breast development in little girls happening at slightly younger ages. And there is a bit of a shift, but that varies quite a lot, depending on which country in the world you’re looking at. And of course, which ethnic background of the girl that you’re looking at. Because Caucasian girls don’t tend to grow breasts as early as girls who may be of African-American background. Girls of Asian background might be growing breasts slightly later. So it does vary.

Dr. McKay: So when we talk about when puberty begins, we have to be quite precise about that and look at the data. Periods are starting earlier than they used to a couple of hundred years ago, but not any earlier than they were in the 1960s. So I think we’re kind of on safe ground there. What’s causing this early but still probably normal breast development in some girls, there’s lots of theories around that. Perhaps some of it is around obesity, being slightly overweight. Perhaps some of it is around the food that’s being eaten. Some of it could be around stress. But it varies quite a lot globally.

Andy: And so does things start changing like emotionally during puberty? It seems like we associate that with all the mood swings. Is that because of the hormones? The hormones start flooding in and then the mood swings kind of start as a result of that?

Dr. McKay: Yeah, look, I think that that’s probably one of the biggest myths out there around hormones and around females and around the brain. And certainly, when I went into writing my book, I thought the book was going to be a lot around hormones and the role that they play in terms of how we think, how we feel, and how we behave. And I always, and I talk about this at the very beginning of my book and teach this all of the time, and I’m always talking about it, if we think about the brain, the brain is receiving constant streams of data from hundreds of different sources from within our body. So that includes our hormones, but it also includes the food we eat and the muscles that we are moving and the amount of oxygen and carbon dioxide in our blood, our pH, our body temperature. There’s a lot of signals coming in from our body. There’s also this constant stream of signals coming in from the outside world. Whether that be is it light outside, is it dark outside, who are the other people out there, are there some types of stressful events.

Dr. McKay: And then of course, because we are humans, we have this enormous prefrontal cortex, we have to add into that, we might call our mind or our psychology, our thoughts, the meaning that we are making of all of these signals. So when we look at what’s happening in puberty, of course, we have this quite striking change whereby in a girl there’s a signal from the brain down to the ovaries that it’s time to start heading down towards your reproductive life and to start producing hormones. And we sort of see monthly cycles start to emerge. And if that’s happening in around ages 10, 11, 12, 13 in most girls, that’s around the time we start to see puberty happening, there’s an awful lot going on at that point in the lifespan as well.

Dr. McKay: So of course we’ve got the hormones, but we’ve also got a lot of the body changes that we see taking place. We’ve got the meaning someone’s making of the changes taking place in their body and also the context that those changes are taking place in comparison to friends. We are seeing, and it depends where you live in the world what specific year that happens, but we see that transition from primary school or elementary school through to high school, or secondary school. We see significant shifts taking place in friendship groups. We see a whole lot of things happening there.

Dr. McKay: So simply to go hormones cause bad moods, one, doesn’t take into account all of the many, many, many changes that are taking place in the lives of young teenagers with maybe boys or whether they be girls. And particularly for girls, it completely sets up a wrong and often lifelong narrative that anytime she’s feeling grumpy, cranky, angry, sad, let’s blame hormones. And that removes any agency from sort of taking a look at but what else is going on. There’s this really great study, which kind of almost illustrates this in even more detail. There’s an Australian longitudinal study of childhood that’s been going on here in Australia for a number of years, tracking children as they go through childhood, adolescence, and into their older years. And it’s been looking at the emergence of what we might call this kind of emotional turmoil of adolescence. And looking to see the relationship between that and hormone status.

Dr. McKay: And what we see, if you think about a young girl going through puberty, a little girl who perhaps her breasts start growing, maybe she gets her period at 10. Early, but still completely normal and healthy. Now she’s probably going to be more vulnerable to develop mood disorders compared to a girl who perhaps goes through that same experience at age 12 around the same time as her friendship group. But what happens when a boy goes through puberty? You get a boy who enters puberty before his friends, gets taller, bigger, muscle-y, hairier, and he rises in social stature amongst his friendship group. And he’s in a sense protected against the development of mood disorders. Versus the little boy, and we all had one in our class, think back to high school, that guy who didn’t start growing until he was about 16. He’s far more vulnerable.

Dr. McKay: So what have you got there? You’ve got young people all experiencing hormones for the first time, but their emotional experience is dependent on their friendship group, on the social context they’re in, how they perceive changes in their own body taking place in relationship to other people, not simply hormone behavior or hormone emotion.

Andy: And the timing of the onset, you point out in your book also, there’s one study you talk about girls who experience early puberty are more likely to suffer from depression than late bloomers. But that doesn’t happen to early developing boys. Instead, boys are more susceptible to depression if they go through it later.

Dr. McKay: Yeah. And again, here, it’s not simply, and this happens, it doesn’t matter at which point in the lifespan, whether we’re talking about males and females or ovaries or testes, testosterone, estrogen, it is very, very hard, nearby impossible, to draw a really straight, neat line between hormone and emotion. It’s almost always contextual. And essentially, what the hormones often do is perhaps dial up or dial down the volume or the treble or the bass and all of the things that are taking place in a changing brain. I think it would be far more useful for many people to start thinking about hormones kind of opening up this great phase of plasticity in teenagers’ brains, whereby things like social context, social cognition really, really matter, because that’s essentially what the hormones are doing. They’re switching on all of those parts of the brain, all that circuitry that’s involved in the development of sexual behaviors, but also, really importantly, the development of social cognition.

Andy: So, we’ve all heard about the differences in terms of the ability to rotate objects in your mind and the mathematical abilities and how boys develop those so much earlier. So what’s going on with that? Is that based on hormones or what?

Dr. McKay: Well, it’s kind of curious because we only ever seem to hear about the skills that males appear to do better in than females. We never hear about the skills in females.

Andy: What about those female-led skills. Yeah, where are those at?

Dr. McKay: Well, I think what’s really, really important, is once again-

Andy: Oh, empathy, they’re good at like being nurturing and motherly.

Dr. McKay: Yeah, yeah, yeah. Actually, if we look at overall cognitive scores and we look at a whole battery of different types of cognitive tests you can do, what we only ever looking at is the difference in averages, the difference between. We’ve looked at a thousand girls and a thousand boys. We might see a really, really slight difference between the means, but we’ve got tons and tons and tons of overlap in those skills. We do actually see this ability to rotate a 3D object in your mind’s eye. The average male is perhaps slightly better at that than the average female, but that doesn’t mean that plenty of girls aren’t really good at that and plenty of guys aren’t really hopeless at that. We don’t know whether that slight difference in men, the main difference that we see, comes about simply because of hormones, does it come about via some kind of patterning that takes place in utero, whereby testosterone released from the infant’s male testes somehow patterns the brain to be able to rotate a 3D object. Or is it something to do with childhood play, something to do with behavior, something to do with learning.

Dr. McKay: Similarly, as I said, there’s plenty of cognitive skills that on average women may be slightly better at than men. And one of them is remembering a list of words, or being able to retell a story that was told to you 10 minutes ago and to try and remember all of the details of that. We don’t really know, because we are looking at humans and we are super complicated, where those differences emerge. How much is gene? How much is environment? What’s nature, what’s nurture? It’s probably a combination of the two. And I think most, most, most importantly to realize is that we couldn’t open up the skull of a random human and look at their brain and go, “That’s a boy, that’s a girl, that’s a male, that’s a female,” by the structure, or even the functioning of virtually all of their brain. Most of the differences are pretty subtle. And most of the differences are around microcircuitry that is involved in things like circuits involved with ovulation. Obviously, the dudes don’t have them and the girls do. We’re really looking at quite subtle differences there.

Andy: Ovulation is also, of course, an interesting topic and just fertility in general. And you talk about birth control. And I think that’s a topic that comes up with parents and teenagers and starting birth control and having that conversation with daughters. And I wonder what parents should kind of think about or consider in terms of the neuroscience and just how that affects the female body.

Dr. McKay: Yeah. Look, I think that’s a really enormous, big and important topic, and there’s obviously lots of different types of contraception, but I assume we are here talking about the oral contraceptive pill as being perhaps the most relevant in terms of thinking does it in any way change the brain? Is it good? Is it bad? Is it neutral? And there have been luckily in more recent years, quite a lot of studies done on this. And a lot of them have been pulled from Scandinavian countries where they have really, really detailed healthcare records for every person in the country. And they can pull all of the data from those studies. So studies have been done for example, of 800,000 women looking at the effects of the oral contraceptive pill on the subsequent emergence of perhaps mood disorders, depression, and perhaps prescription of antidepressants to take a look and see.

Dr. McKay: And what’s really interesting is when you look at the data and you stratify out by age, you see quite different, not enormous differences between people on the pill and people not on the pill, but we do start to see differences emerge between two groups, the younger that the girls or women are when they start taking the pill. So if we look at say a group of adult women who are all in their thirties and half of them start taking the pill and half of them don’t, we don’t really see when we’re looking at these studies of 800,000 women any real difference in the development of subsequent mood disorders whatsoever. And that data’s pretty clear. But there are differences, although not enormous differences, but there are differences in much younger teenagers. So if we look at groups of girls aged between, and sorry about my loose language here, girls and women. I’m not intentionally being loose with my language, but for the purposes of this podcast, it’s easiest to go with that.

Dr. McKay: If we look at girls between age 14 and 16 who have started taking the pill at that age, we do see that there are more girls who are on the oral contraceptive pill subsequently being diagnosed with depression and being given antidepressants compared to girls not on the pill. But the absolute difference in risk is not actually that enormous. If we had a hundred girls on the pill, four of them would subsequently be diagnosed with depression and given an antidepressant. If we have a hundred girls not on the pill, we’re seeing one girl. So the difference is really only three out of a hundred girls. We’re going from four out of a hundred versus one out of a hundred.

Andy: Still got a pretty good sense.

Dr. McKay: So I think we can tend to zoom in and focus in on the negative headlines and kind of worry about that. And also we have to remember that a lot of the time this data is reporting, and this is getting kind of into the nitty-gritty of science communication. We’re not looking at the reports of absolute risk and the absolute risk here is from one in 100, one in a hundred girls to four in a hundred girls ages four to 16. And that virtually disappears by the time you get 30, mid-twenty. So there are a lot of things that can contribute to your any particular emotional state or any particular mood disorder. There’s many shades of blue. Hormones are one voice in the crowd, but there are other voices in the crowd which are a whole lot louder. And we kind of touched on that when we talked about puberty and social context. Other people, and your perception of yourself and what’s going on in your social context is a far greater indicator of any health state, particularly your mood or your emotional state.

Andy: Parenting experts today talk a lot about the neuroscience of the teenage brain and the emotions and the prefrontal cortex not being mature yet. So not being able to regulate the emotions. And I thought it was interesting in your book, you talk about what teenagers actually think when you talk to them about the teenage brain and neuroscience. So is that a good idea to talk to a teenager and lecture them all about how the teenage brain works?

Dr. McKay: Well, I’m not entirely sure whether lecturing teenagers about how anything works usually goes down too well. I think it is really, really disappointing to me as a neuroscientist and as someone who talks about a lot of these ideas and our relevance to our everyday lives is that the teenage brain is often dismissed or derided, or is an oxymoron. Teenagers don’t have brains, or they’re half developed. And it’s so dismissive and judgmental.

Andy: That sounds really condescending. It’s like, “Oh, your brain, it’s so limited. It’s really—it’s stifled.”

Dr. McKay: Teenagers, they notice, and they’re not interested because often it is so, so patronizing. We would never talk about toddlers’ brains in the same way. As an infant and a toddler starts to learn language, we wouldn’t go, “Oh, they can’t speak properly yet.” That’s because their brain’s half developed. That child hasn’t learned to walk yet because their brain hasn’t figured out how to walk yet. There’s no other group of people at any point in the lifespan which we would be so dismissive about and kind of be so reductionist and go, “Oh it’s because their brain’s half developed.”

Dr. McKay: I like to think about their brains as going through this incredibly exquisite phase of learning and plasticity where all of the experiences that they have really, really matter. And they are almost at their peak of learning so many of these new skills. Just as an infant and a toddler around the age of 18 months is going through this explosion of learning new words and being able to learn to speak and their brains are absolutely tuned and have this like a sponge to learn, so are teenagers’ brains. They’re learning about emotional regulation. They’re learning about empathy. They’re thinking constantly about what other people are thinking about them and what that means for themselves. They’re thinking about what other people are feeling and what that means to them.

Dr. McKay: Have you ever tried to redo the calculus that you learned when you were at high school, or rewrite some of those history essays, or done some kind of chemistry experiment that you could do back then? Teenagers are at their peak of learning. They have this remarkably plastic brain which is primed to be able to do all kinds of things with great ease and with great speed that we kind of lose as we get a little bit older. So I don’t think it’s any surprise that the common narrative around the half developed or undergoing renovation to teenage brain is dismissed by teenagers because they’re smart enough to know it’s not very kind. I think we should be praising them for going through this phase of opportunity that they’re going through, and help them tap into and provide the right kind of experience and resources for them to thrive through that rather than dismiss them.

About Dr. Sarah McKay

Dr Sarah McKay is the author of The Women’s Brain Book. She received her PhD from Oxford, and now works as a neuroscientist who translates brain research into strategies for professionals working in health, education and coaching.

Dr. McKay has been published extensively for consumers and professional audiences. She’s been quoted in the Wall Street Journal, The Guardian, Grazia, Sydney Morning Herald, The Age, Mamamia, and can be seen and heard on SBS Insight, ABC Catalyst, ABC Radio National, Radio New Zealand, and Channel 7. In 2019, Sarah hosted an episode of ABC Catalyst exploring brain health, bio-hacking and longevity. Sarah is the director of The Neuroscience Academy, which offers professional development training in applied neuroscience and brain health.

Sarah lives on Sydney’s Northern Beaches with her Irish husband and together they are raising two surfer dudes and one cocker spaniel.

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