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Child Development and the Brain

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Anshu Bahanda: This is Anshu Bahanda on Wellness Curated. Thanks for joining me on this podcast. My mission is to empower you with health and wellness so that you can then go and empower others.

Today, we’re going to talk about development and the brain with Professor Adele Diamond. She is the Canada Research Chair Professor of Developmental Cognitive Neuroscience at the University of British Columbia, UBC, in Vancouver, Canada. Her specialty is the rigorous study of executive functions, or EFs, in infants and children. EFs include creative problem-solving, self-control, focused attention, and working memory. Adele studies how EFs are affected by biological factors such as genes and neurochemistry, and by environmental factors, for example, impaired by stress or improved by interventions. She’s a member of the Royal Society of Canada. She was named one of the 2000 Outstanding Women of the 20th Century, and she was listed as one of the 15 most influential neuroscientists alive today. So, we’re very lucky to have her here. And her impact was recently ranked amongst the top 0.1% of all scientists across all fields. And she’s been doing this for over 40 years. We got so much invaluable information today. Listen to this. 

Let’s get right into stress. So, is stress, even if it’s very mild, ever good for higher cognitive functions and in the development of a child’s brain? 

Prof. Adele Diamond: So, a lot of us were taught that a mild level of stress is beneficial, that there can be a positive level of stress, and it probably dates back all the way to the Yerkes-Dodson curve in early 1908. But nobody ever tested that on people. They only tested it in rats. And recently, when we and other labs tested it, it doesn’t appear that there’s any level of stress, at least psychosocial stress, stress about whether you’re performing well enough, what other people think of you, that is good for the executive functions of most people. It’s really important to try to minimize stress in our lives and it’s more important in young children, because the brain and the body are forming, that stress can have time-limited effects on the adult and go away when the stress is over. But in children, it can set the way the body develops, so that the body stays this way even when the stress is no longer present.

AB: You know, people talk about nature versus nurture, in the development of a child. So how important is the DNA of a child versus the environment in which the child is brought up? 

Prof. AD: That question, we realize now, doesn’t make a lot of sense because it doesn’t make sense to talk about DNA or genetics in the absence of environment or the effects of the environment, in the absence of the genetic background that it’s affecting because they affect each other. The environment affects your gene expression. That’s called epigenetics. Our experiences alter the very expression of our genes. Our experiences and our reactions to them determine which genes get turned on and off and when that happens and which genes stay on. 

AB: Okay.

Prof. AD: Most of the time, 90% of our genes are turned off. So, the environment is going to determine which aspects of our genetic background get expressed and how they get expressed. And then the genes determine how we interpret the environment, how we interact with the environment. So, you might have two children in the same family, and yet their relations with their parents are so different. Maybe one of them is kind of at loggerheads with the parent, their personalities don’t jive so well and the other is maybe more easygoing or gets along better with the parents and everything works fine. So, it’s a fundamental interaction. Let me give you a couple of examples. You may have heard that if a mother has a flu infection during pregnancy, there’s the danger that the child might develop schizophrenia or ADHD because it affects the child’s brain. But it’s not the flu infection in the mother that’s affecting the brain. What it is, is the immune response that the mother’s body mounts to the infection that is affecting the child’s brain. 

AB: Oh, wow! 

Prof. AD: And the mother mounts that same immune response to stress. So, if a mother is stressed during pregnancy, it’ll also increase the possibility of the offspring developing schizophrenia or ADHD when the child grows up. So, the environment, the mother’s environment in the womb, is affecting how the baby’s brain gets shaped. It’s not just genetics that’s determining how the brain gets shaped. The environment is doing that as well. Even mild stress isn’t good for most people most of the time. And in studying that, many labs, including mine, have looked at a gene of which there are two different variations. One variation is called MET, because it has methionine at one location on the gene, codes for a faster enzyme that clears dopamine faster from the prefrontal cortex. The other variant called VAL, because it has valine at one location on the gene, codes for a faster enzyme that clears dopamine more quickly from the prefrontal. Now, stress increases the level of dopamine in the prefrontal. So, in one case, you have ones who already have the optimal level of dopamine and stress is going to maybe push them past that. And you have others, the VALs, who don’t have quite as much dopamine in the prefrontal because they cleared it so quickly, so stress might improve them. And what we found is that it impaired the METs, but most labs didn’t find it helped the VALs. My lab with very, very mild stress found it did. But what I wanted to point out here is that those with the best executive function capacity, which are the METs, who might be the most brilliant, who might have the potential to achieve amazing intellectual feats, are exactly those most likely to fail under pressure because they’re the most fragile in the face of stress. Their dopamine levels are already at the optimum point, exactly those with presumably the greatest potential for success are the ones whose performance on demanding cognitive tests is most adversely affected by stress. 

AB: Incredible. 

Prof. AD: Maybe you have children who you think, well, they’re okay, but they’re not the stars like these other children who are performing so well. But those children who didn’t look like the stars, under stress, when there’s an emergency, may be the ones who can think most clearly, and can come up with creative solutions. In other words, you might think one of your children is good, but the real star is his brother or sister, but the one you think is not the star might be the one better able to function under pressure or in an emergency. That child might end up being your real hero or heroine. So which version of that gene is better, the MET or the VAL? Depends completely on the environment. In a stressful environment, you want to have the VAL version. In a non-stressful, more typical environment, the METs do better. 

AB: I see. But in today’s day and age, isn’t there stress coming from everyone? What I’m hearing is, isn’t there way too much stress at the moment? 

Prof. AD: Yes, this is a very stressful time. You see that in children, you see the effect of that in children a lot. You see, some of them are withdrawn. You see others are acting out. Yes, it’s a very stressful time for most people right now. 

AB: With all the knowledge that you have now about the development of a child’s brain, what tips, techniques, and takeaways can you give mothers of young kids and mothers-to-be, given that the environment is so stressful? 

Prof. AD: The most important element in terrific parenting is simply to love your child. That’s it. Everything else is just variations on the theme. And not to love the child you hope for, but the child you have, shortcomings and all, celebrating his or her inner beauty and strength. Children, and we adults too, need to feel there are people who care about us, believe in us, and will be there for us. We need to feel heard and seen, really seen and valued for who we truly are. That’s what children need. Everything else is just extra. 

AB: Wow!

Prof. AD: Years ago, in the book “The Road Less Traveled”, Scott Peck pointed out that children who are truly loved know themselves to be valued. That knowledge is worth more than gold. Because when children know they’re valued, they feel valued. And if you feel valuable, then you’re going to do what’s needed to take care of yourself and help yourself prosper. So, a parent’s caring is more important than their knowledge or skill, material possessions, or doing the textbook-perfect thing. So, my advice to parents is to relax. You don’t have to have studied lots of books or be up on the latest theories of this or that. It doesn’t matter if you don’t have much money and can’t afford the newest toys or gadgets. It’s not important. Your humanity is what matters most. You are enough. 

AB: You just said something very, very valuable. All of us parents make that mistake. You said, “accept the child for who they are, not for who you are trying to make them or who you want them to be”. That’s such a valuable tip you’ve given us. Thank you for that.

Prof. AD: Let me go back to my specialty, which is executive functions. Executive functions depend primarily on a part of the brain called the prefrontal cortex, and the other brain regions it’s connected with. Now, the prefrontal cortex is the newest area of the brain over the course of evolution, and the area of the brain that takes the longest to mature over a person’s life. The result of that is the prefrontal cortex is the most fragile and vulnerable area of the brain. So, if you’re sad, stressed, lonely, or not physically fit, the prefrontal cortex is affected first and affected most severely. And that also applies to executive functions. So, if you want good executive functions, if you want good prefrontal cortex functioning, you have to care that the person is socially supported, emotionally supported, and in good physical health. The whole person- mind and body, intellect and emotions are fundamentally interrelated.  The different parts of the human being: cognitive, social, emotional, spiritual, and physical are fundamentally interrelated. 

AB: So, given where we are today and given the state of the world at the moment, a lot of it is to do with mental health, in children. So, what are some of the proven ways to reduce stress? 

Prof. AD: One thing to do is to let children know without any question that you believe in them. Children need to believe in themselves. And what’s critical for that is to see that you believe in them, that you fully expect them to succeed, to find their way. And that’s different from saying, I expect you to get all A’s, or I expect you to go to medical school. I expect you to find your way. I expect you to succeed in life, whatever that success means for you. Not something the parent had in mind at the beginning. And our expectations for a person have a huge effect on what that person expects for themselves. And what you expect for yourself can become a self-fulfilling prophecy. An example of that comes from social psychology, where there’s a little cottage industry in a field called stereotype threat. There are many stereotypes in our culture. One of them is that in general, men are better at math than women. A group of researchers went to a university, gave university students a standardized math test, and no surprise, as a rule, the male students performed better than the female students. Then those researchers took exactly the same test to a completely comparable group of university students. And the only difference was this time they said, this particular test has been designed to be gender-neutral. And what happened? The women performed as well as the men. It was the same test, the only difference was the expectations the women had for themselves. So it’s so important to help children believe in themselves, have good expectations for themselves, and have hope. And hope is a socially supported vision. It’s hard to hold on to it if no one else shares that vision with you. So, you need to make it absolutely clear that you share that hopeful vision with your child. Eric Erickson considered hope to be the earliest and most indispensable psychological strength. And a Gallup Poll study of 70,000 students in the US. found that the hope that children in grades five to twelve expressed predicted their college grades and college success better than their high school grades or standardized test scores. So, one thing you can do is believe in your child and let your child know that.

AB: Incredible. 

Prof. AD: Other ways to reduce stress are to have things be predictable. Unpredictability, surprise can be stressful. So, you want a stable routine- clear limits, clear expectations, consistency. Then there are lots of things that can reduce stress. Pets, I’m a huge fan of pets. And a dog in the classroom has been shown to reduce stress in the classroom and help children pay attention better. And that’s true from preschool all the way to university. Being out in nature relieves stress. Exercise reduces stress. Mindfulness reduces stress. Movement-based mindfulness activities reduce stress. Like tai chi or taekwondo or qigong. Touch relieves stress. I’m a huge fan of hugging. Showing compassion to yourself relieves stress. The Western emphasis on self-reliance, not being dependent on anybody is wrong and destructive of your mental and physical health. For children who’ve experienced stress in their lives, and who had traumatic experiences, those experiences can be things as common as a lot of conflict in the home, arguing between the parents, feeling unloved, feeling humiliated, and having somebody with mental health problems in the home. If they have a really nurturing adult in the home, the effects of those stressful experiences are mostly mitigated. It doesn’t affect their health or their psychology nearly as much as it would if they didn’t have a responsive parent in the home. Okay, children who’ve experienced adverse childhood experiences at least two or more already by the age of five have shorter telomeres. Telomeres are the protective tips at the end of a chromosome, the same way the plastic tips at the end of shoelaces protect your shoelaces. The plastic tips keep your shoelaces from fraying and telomeres keep chromosomes from fraying. When a telomere gets too short, a cell will die or malfunction. And children who’ve experienced adverse experiences already by age five have shorter telomeres. This is a wonderful study that shows that children who’ve experienced just as many and just as bad early adverse experiences; if they’re lucky enough to have incredibly responsive and empathetic moms, there is zero effect on their telomeres. Zero effect, it totally wipes it out. 

AB: Wow!

Prof. AD: And then Alicia Lieberman did a study that showed that normally, if you’re maltreated as a child, you will often experience PTSD as an adult post-traumatic stress syndrome. But if you have even fleeting memories of benevolent child-caring experiences, there’s no significant effect between early maltreatment and PTSD. Now, that doesn’t mean that if you have even fleeting memories of warm, caregiving experiences, you’re going to have no problems as an adult. It just means you’re not going to have the severity of PTSD. You need more than fleeting memories. 

AB: Wow!

Prof. AD: Parental sensitivity and warmth also override the negative health consequences of being born with low SES, low socioeconomic status, lower income, less prestige, or respect from the wider community. Normally, children who grow up in low SES families have increased inflammatory signaling. Their immune system starts to attack the body. Normally, cortisol shuts down your immune response. So, for example, when you get a cut, you’ll often see that there’s some swelling where the cut is, and that’s your body sending the immune system there to protect you from infection. That’s good. You want that, but you don’t want the swelling to stay there forever. So, you want to send cortisol to tell the immune system, it’s okay, now you can calm down, and the swelling will go down. But if you’ve experienced severe stress growing up or repeated stress growing up, what happens is you keep manufacturing cortisol. And when the body keeps getting cortisol, it does the same thing that you would do if somebody kept nagging you all the time. They closed their ears to it. The receptors for cortisol don’t pick up cortisol anymore. They’ve had it. You’ve been sending too much to me. I don’t want to deal with you. Go away. Well, if the receptors for cortisol can’t receive it, then cortisol can’t do its job. Cortisol can’t shut down the inflammation. So, if you’ve experienced a lot of early stress, you have problems with the immune system going uncontrolled, which can attack your heart. It can attack your lungs. It can attack your joints. You can have any number of problems. But if you have high maternal warmth growing up, you’re less likely to have this than if you didn’t. It can completely override the effect on the immune system of being born low SES. 

AB: Wow!

Prof. AD: Much of the research is with mothers. A little bit of the research is also with fathers. But I don’t think, it necessarily has to be a parent. I think just one adult who believes in you, cares about you and is always there for you, can make all the difference in the world. And that’s one of the reasons, for example, that asthma is more common among children in low SES because there are two requirements for asthma. One is you need an environmental irritant, and the other is you need stress. Take away either one and you get rid of the asthma. So, the children who have low SES, who are showing asthma, are showing it because either now or earlier in their lives, they’re experiencing stress. 

AB: So much to learn. So, tell me, what should parents or teachers do when a child misbehaves? Because very often what happens is people don’t know how to react. 

Prof. AD: We usually react based on where we think the action is coming from, or what we think the intention of the person is. I think when a child misbehaves, we need to step back for a moment and use the executive function of inhibitory control to not react immediately. Is the child stressed? Is the child hungry or sleepy? Maybe the child is reacting from hurt. Maybe something upset the child today. Often a child will come into a class and be absolutely obnoxious, so difficult, so hard, and you think, “oh, my God, how am I going to deal with this kid?” and if you realize that maybe he’s acting like that because he’s been terribly hurt and he’s afraid that you’re going to reject him, so he’ll push you away before you have a chance to push him away, or he’ll test you to see if you’re really somebody he can feel safe with. If we see the behavior as coming from hurt, we can react completely differently. Be sympathetic and supportive instead of disciplinarian and angry. 

AB: You know that there are all kinds of research that is done, but I love the way you’re explaining it because there is a school of thought which is all about discipline, discipline, discipline. And I almost feel like sometimes, it takes away the joy of a child’s life. 

Prof. AD: In Vancouver, many people have dogs. Most people are responsible dog owners and take their dogs to dog obedience training when they get it. And in obedience training, they’re taught that dogs don’t respond well to punishment, to negative reinforcement. They only respond well to positive reinforcement. Unfortunately, we don’t tend to have these classes for parents. Children, like dogs, don’t respond well to negative reinforcement or punishment. There’s an old law in physics that one force generates a reaction, an opposite reaction. You want everybody to be on the same page, figure out a way that the child will want to do it. If teachers think they have to force children to learn, that’s just silly, because children are naturally curious. We can scrub that out of them by giving them miserable experiences. But they start out totally curious, totally wanting to learn, totally wanting to grow. Children are not lazy. They want to work, they want to grow. Why would they ever walk on 2 feet if they were lazy? They get around much better crawling. 

AB: Any last words of advice? 

Prof. AD: I guess my last word of advice would again be to relax. Because if you’re stressed, you can’t be the parent or caregiver you want to be, and it’s going to impair your own physical health and your own mental health. And once you relax, help your child to relax. 

AB: That’s really wonderful. Thank you so much for giving us your time. Thanks for joining us. Hope you enjoyed the Wellness Curated podcast. Please subscribe and tell your friends and family about it. And here’s to you, leading your best life.