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Welcome to Intelligence Squared, I'm Conor Boyle. It's the Sunday debate and we're revisiting a conversation from 2018 in which we got to the heart of nature versus nurture. How much do our parents influence the people we turn out to be?
It might feel like the most natural thing in the world, but parenting, how to do it well, and the tools to do it with is a multi-billion dollar industry. Books such as Raising Happy Kids and The Conscious Parent tell us that we're very much in control of the situation.
But is it really that simple? Back in 2018, we brought together a panel of experts to explore just how important parenting is. We were joined by Professor of Behavioral Genetics Robert Plowman, Susan Polby, the Developmental Clinical Psychologist. Therapist, parenting counsellor and broadcaster Anne Plachette Murphy and Stuart Ritchie who you may have heard on the podcast previously with his book Science Fictions and he's a lecturer in social genetics and developmental psychiatry.
Our host for the debate was doctor and TV presenter Zand van Tulleken. Just hit that subscribe button and you'll be directly supporting us in continuing what we do, bringing you deep discussions, smart debates and asking the big questions. Now back to today, here's Dr. Zan Van Tulligan with more. Thank you all for coming. This is very exciting. The motion is parenting doesn't matter or not as much as you think. We have four amazing speakers.
Let me talk you through our first speaker who is in favor of the motion. Robert Plowman believes that parenting doesn't matter. or not nearly as much as you might think. He is a psychologist and a professor of behavioral genetics at the Institute of Psychiatry, Psychology and Neuroscience at King's College London, and his new book, Blueprint, How DNA Makes Us Who We Are.
argues that the most important thing our parents give us is our genes and that parenting styles don't really affect children's outcomes. Robert, take it away. When I was in graduate school 45 years ago, psychology was so dominated by environmentalism, the view that we are what we learn, that genetics, it was dangerous to even mention genetics.
We were told for example that schizophrenia was caused by what your mother did to you in the first few years of life. In the ensuing 44 decades, a mountain of evidence has accumulated that has convinced most scientists of the importance of inherited DNA differences in shaping who we are as individuals.
That message is getting pretty well known, but what isn't quite as well known is the other part of the message, and that is these are the best evidence we have for the importance of the environment. But the data show that the way the environment works is very different from the way environmentalists thought it worked. It's not due to systematic environmental influence like parenting.
that we would call nurture, that the salient environmental influences are essentially idiosyncratic, stochastic, in a word, random. So I'll try and convince you of that in my... remaining nine minutes. But to summarize it, an easy way of remembering it is that I'm saying that if you were adopted at birth, you were reared by different parents,
You grew up in a different family, you went to a different school, had different friends, had a different job. You would essentially be similar to who you are now. And that isn't just a thought experiment. went to, grew up in New York, and at 19 he went to upstate New York to go to university. And on his first day on campus, people came up to Bobby calling him Eddie, and they seemed to know who he was. And he found out soon because he met Eddie. And he said it was like looking in a mirror.
This other person was very similar to him. And then it turned out they had both been adopted at the same adoption agency in New York City. And the publicity that came from this... brought out a very rare case of an identical triplet who is also extremely similar. And they're not just similar physically, they're also similar psychologically.
They're all in personality. They're all outgoing. Their interests are similar. They're all interested in acting. And they're also similar in terms of mental health and illness. They're all prone to depression. But although it's dramatic... You don't need identical twins reared apart to separate nature and nurture. So Zand and his brother Chris, as you know, are identical twins.
And they're actually more different physically than a lot of identical twins. Zand is the short, chubby one. He's a half inch shorter than his brother Chris. I'm just going to vote now. Yeah. Six kilos and counting, heavier. It is. But some quite deep research. So although they're reared together, you can compare identical twins.
to non-identical twins. 1% of all births are twins, one-third are identical twins. Identical twins are clones, they have the same DNA. Non-identical twins, like any brother and sister, are 50% similar genetically. So that method, the twin method, has been used to study hundreds of psychological traits.
And that's what I've done in my study in the UK that I began when I came to England in 1994. It's called the Twins Early Development Study. So we've studied a lot of aspects of childhood development, and we find, like everyone else does, that about half of... the differences we see in kids psychological development, including educational achievement and mental health and illness, can be explained by genetic differences.
But that means 50% is environmental. But these environmental differences aren't due to nurture. They're not due to systematic forces in the family that make kids in a family similar. Whatever it is, it's making two kids in the same family as different as kids in other families, and that includes identical twins. A method that makes it easier to understand that is the adoption method. So parents and offspring share nature and nurture.
But with adoption, you can separate those two. You can study genetic parents who share nature but not nurture. These are biological parents and they're adopted away kids. And you can study environmental parents, adoptive parents who share nurture but not nature. with their children. So for weight, for example, you can predict a child's about 10% of the differences in children's weight with their parents' weight. Is that nature or nurture?
Relationship between... With adopted children, you can't predict any variance, any differences between the kids' weight from their adoptive parents. There's no relationship between the adoptive parents and the adopted children. Whereas those adopted children are correlated as much with their birth parents, who they never saw after the first year of life, as are children reared by their biological parents, suggesting the importance of nature.
and not nurture. So I want to emphasize that we're talking about differences, why children differ in personality and mental health and illness and mental abilities and disabilities. And we're describing those differences. There's two caveats that are very important. We're describing what is the genetic and environmental factors that exist in a population at the time we study it.
We're not talking about what could be. So weight, you may be surprised to know, is about 70% heritable. That means of the differences in weight in this room, about 70% of the differences are due to inherited DNA differences. Even if it was 100% heritable, it doesn't mean you can't change your weight. If you stop eating, you lose weight. So this is the difference between what is and what could be.
And a second caveat that I think is very important in terms of the other speakers is that we're talking about the normal range of environmental and genetic influences. We're not talking about the genetic extremes of rare mutations that can have devastating effects. on a child. Nor are we talking about the environmental extremes like neglect and abuse. And then thirdly, a third finding is we call the nature of nurture that
a lot of what looks like systematic environmental effects is actually reflecting genetic differences. So we find that hundreds of studies have looked at the correlation between... aspects of parenting and children's outcomes. But you can't assume that correlation is causal environmentally because parents share 50% of their genes with their children. And furthermore, we know...
that parents respond to genetic differences in their children. Unless you have a genetically sensitive design, you can't separate out the effects of nature and nurture. I think our relationship with our children should be based on loving them rather than changing them. Instead of trying to change children, we can. There's the difference between what is and what could be. We can change them. But instead of always trying to change them and molding them into what we want them to be.
Doesn't it make sense to think about going with the genetic flow and find out what they like to do and what they're good at and help them to do that because you love them. You want what's best for them. And I hope this is a liberating message for parents, one that relieves them of some of the anxiety and guilt that is piled on parents by parent-blaming books.
that scare parents into thinking one false move and their child is going to be ruined forever. So in conclusion, I suggest that parents relax and enjoy their relationship. And that part of this enjoyment comes from watching our children become who they are genetically. Thank you. Robert, thank you very much indeed. Well some of you may feel that that let you off the hook a bit.
But others of you may be wanting to feel useful and that you can make a difference. Unfortunately for you, our next speaker is going to argue against the motion. Susan Paulby is a developmental clinical psychologist and a visiting senior researcher. Thank you. on their offspring from childhood into young adulthood. Susan, take it away. Ladies and gentlemen, parenting does matter, and maybe more than you think, and this is why I'm opposing the motion.
We all have two biological parents. Most of you will know who they are. Some may not. I invite you to hold your parents. or those who cared for you as a child, in mind? Ask yourself this question. Have your parents, and the way that you were brought up, whether for good or ill, had an influence on your life and who you are today? Robert would say, not really. In fact, he has said that if you'd been adopted out of the family...
gone to a different school, held a different job, you would essentially be the same person as you are today. I think this is not true. I believe that parenting does matter. And what is more, it matters even before you are born. Evidence based on 30 years of research shows that our experience in the womb has profound implications for our well-being. from conception to death. Exposure to maternal depression as a fetus has an impact on the well-being of the infant, child, teenager, and young adult.
In order to show you how important parenting is during the nine months of pregnancy, I will describe how rapidly the human fetal brain develops. At four weeks, the brain of the embryo is not much bigger. than a grain of salt. And at seven weeks, it barely measures six millimeters. But fast forward to the final trimester. And the developing baby's brain has increased in size by 260% to 341 cubic centimeters, a third of the size of the adult brain.
And this does not happen on its own. The developing fetus collaborates with the mother on a mutual construction project. The fetus needs the mother to provide an environment that's healthy. And this does not just mean good nutrition. David Barker was the first to show that the environment of the womb plays a powerful role in influencing our later susceptibility to certain chronic diseases.
and how long we live. Studies have shown that if you stress an animal during pregnancy, this will have long-term effects. But we didn't know if this happened in humans. Because it's unethical to stress a human fetus. We have to wait for natural or man-made disasters to occur. Changes brought about by undernutrition during gestation.
were found in the children of pregnant women exposed to the Dutch famine at the end of World War II. These children were more susceptible to diabetes, obesity, and cardiovascular disease. The finding that certain circumstances in life can cause genes to be turned off or turned on is what we call epigenetics. This is something that Robert has let go.
And yet it is of fundamental importance when we think about how parenting matters or doesn't matter. Michael Meany, one of the world's leading epigeneticists, discovered the importance... of maternal care in modifying the expression of genes that regulate the stress response. In other words, mothering changes gene expression. Yuda's work with pregnant survivors of 9-11 also showed that traumatic experiences can leave epigenetic marks that alter the stress response in the offspring.
The children of women who were raped by the rebels and then forced to kill while pregnant in northern Uganda showed psychosomatic symptoms in the form of fainting spells, as if they were dead. The effects of traumatic experiences last. Whether or not they are emotional in the form of bullying or antipathy or physical or sexual or in the forms of neglect.
or in the form of having someone in the family with a mental illness, domestic violence, substance abuse, divorce. Our experiences as children will affect us when we are pregnant and will have an effect. on the unborn child. And we cannot let fathers off the hook here either. Recent studies have shown that paternal environmental and nutritional factors also affect the phenotype of the offspring.
by altering its genome. But as Annie will tell you, the good news is that positive experiences in early life of the newborn can build resilience and protect him or her from the effects of trauma. Let me end by asking another question. What do we want for ourselves and for our children? Most of us would say that we want to be happy and that we want our children and grandchildren to be happy.
I would not be standing here today based on my polygenic score for debating. It is the care that I've received from my parents, the way that my father got me as a shy little girl, to practice speaking aloud. in order that I could take part in a play. And from my three children, yes, parenting can go in both directions. How else would I have learned to be a risk taker?
I certainly did not get that from my parents, as my children can testify. It is my experience of being parented and of being a parent that's made a difference and shown me that... Parenting does matter and does make a difference. I urge you to vote against the motion. That's great. Well, I imagine many people are feeling firmly back on the hook. For me, it's extremely close. Different data sets, extremely compelling arguments. Our next speaker...
He's also speaking for the motion. Stuart Ritchie is a lecturer in the Social Genetic and Developmental Psychiatry Centre at King's College London. His research focuses on intelligence and cognitive abilities using genetics and brain imaging and other methods to shed light on why some people are smarter than others. The people in this room, presumably. Thanks, Stuart.
Good evening. Thanks very much for coming along and thanks to Intelligence Squared for inviting me along tonight. Parenting does matter, but it doesn't matter as much as you think. The effects of parenting have been hugely oversold. I think we still live to some extent in the shadow of Sigmund Freud, who dreamed up all these arcane theories of how...
Even seemingly innocuous acts by the parents could have a really grave effect on their children's life outcomes. My favorite example being, he theorized that, at least in some cases, children's asthma... was caused by them overhearing their parents having sex and imitating the heavy breathing that they heard. That's true. That's not made up. That's true. Well, it was made up by Simon Freud. It wasn't made up by me.
And so despite this kind of absurdity, we still follow Freud in making that assumption that parenting matters a great deal. This assumption that differences between people are caused by differences in their parenting has been called the nurture assumption by Judith Rich Harris in her book in 1998. is so pervasive that it even affects the research of scientists who should really know better. Take, for instance, a study just published a couple of weeks ago in the journal Social Science Research.
The Guardian wrote this up, and their headline was, Growing up in a house full of books is a major boost to literacy and numeracy. And in the study, across several countries, children who did better at school... tended to be from homes that were full of books. So more books, better grades. But there's a gigantic flaw, as Robert was saying in his speech, with this kind of research. Not only was this just a correlational...
and not an experimental trial that randomly assigned children to homes of different library sizes, which probably wouldn't get past the old ethics board. But it did miss... an extremely important source of similarity between parents and children, and that is their genes. Parents don't just socialize their children into a love of reading and learning. Brighter parents... Both have more books at home and tend to have brighter children. And that's because they have passed on a genetic...
The tendencies to be smarter, more inquisitive, more academically inclined are all really all linked in part to genetics. And indeed, the behavior geneticist Eric Turkheimer has called this the first law of behavior genetics. That is, all human traits are, to some extent, heritable. And forgetting the first law... when you're doing research, is pretty mortifying. And that study about books in the home didn't even mention the possibility.
that genetics might explain some of the reason. I even did like control F genetics on the paper and there was nothing in there. But as I said, this is a very, very common mistake in research. Any study... as Robert said, that reports a correlation between some parenting behavior on the one hand and some child outcome on the other, and that doesn't take into account the effects of genetics, is, for all practical purposes, useless, with only a few exceptions.
And to be completely clear, I'm not saying that the research shows parenting has no effects at all. Indeed, if you do the proper studies, the ones that can control for genetics, so twin studies, adoption studies, and so on... you do find potential parenting effects for a few outcomes, like educational attainment and so on. And we don't really even need fancy genetic, behavioural genetic studies.
to know that parenting can't be all that important. Because it's a common observation from parents who have multiple children that each individual child shows very different behavioral tendencies from a very early age. And that's backed up by research where...
siblings don't correlate, unless they're identical twins, don't correlate all that strongly on most outcomes of interest. And so a common response on hearing this kind of argument is, well, okay, if what you're saying is true, and parenting only has small effects, How maybe I shouldn't bother doing nice things for my child, like music lessons and ballet classes and reading to them at night and so on. But that would be to completely miss the point.
You should do all these things not because you think they'll shape your child's life outcomes. It's because they're inherently valuable. Music and dance and literature are some of the best and most interesting things that humans do. And getting your child into them needn't be contingent on whether you think it'll add a few IQ points. And that's before we get into the truly eye-watering.
array of parenting fads and trends that pop up and disappear. Baby wearing, hot housing, tiger parenting, setback education. elimination communication, helicopter parenting, attachment parenting, detachment parenting. free range kids, quality time, the family bed movement, baby Mozart, baby yoga, mindfulness for kids, grit, growth mindset, paleo diets, and even something, and I hesitate to even mention this.
called orgasmic childbirth. And the reason that all these kind of fly-by-night trends and fads are so short-lived... is very simple. It's because they're all pretty much useless at changing the way children turn out. These are things which, dare I say, middle-class parents get into because essentially... all the basics are covered. Their child will probably do fine either way. But what about children who don't have the basics covered?
This is where parenting really can matter. So for the minority of children who are at high risk of conduct disorder, so problems with disruptive and antisocial behavior, there really is experimental evidence from meta-analyses. that shows that interventions that teach parents to be more responsive and set limits and so on, really can have at least a moderate effect, at least in the short term.
on their children's behaviors. Most parents should relax and feel less anxious about the long-term effects they might be having on their child. And they should also feel less guilty about not engaging in one of those parenting fads that I listed. that have more than likely zero benefits for how their children will turn out. And that said, we do need to do more work to examine how... Parenting might affect kids who are at high genetic or environmental risk for psychiatric or behavioral problems.
So as Steven Pinker has argued, children aren't just blank slates or lumps of clay that we can shape and mold in any way we wish. And if we understand that normal range parenting has... at best, modest effect, we can focus less on trying to force children's lives down a particular path and more on treating them and enjoying their company as fellow human beings. Thank you very much.
Stuart, thank you very much. And I would urge anyone who has the choice to choose free-range kids every time. It's also nice to know that control F shortcut. I imagine if you get nothing else from tonight, that's pretty helpful. If you've made it this far into the podcast, you're obviously enjoying it. So please leave us a review or a rating on iTunes so that more people can find out about the Intelligence Squared podcast. And now back to the show.
I don't know about you. I feel like a cat chasing a laser pointer. I am being yanked back and forth. Extremely persuasive arguments. But I'm sure we will hear more persuasive arguments from our final speaker. Anne Plachette Murphy is a therapist. and a parenting counselor. She was the parenting correspondent for ABC TV's Good Morning America and she was the host of Parenting Perspectives with Anne Plachette Murphy on ABC Now.
Her books include The Seven Stages of Motherhood, Loving Your Life Without Losing Your Mind. which is surely what we're all trying to achieve. And she serves on the board of, and was in fact previously the board president of Zero to Three, the leading American organization dedicated to promoting the well-being of infants and toddlers.
Thank you, Zand. And good evening. Sorry, before I begin, Stuart, your mother would like you to call her right after the debate. Well, one of the disadvantages of going last is that... what you thought you were going to hear from the... proponents of this motion was not what I heard at all. And in fact, having read Robert's book several times, I'll tell you that he's a little bit of a wolf in sheep's clothing tonight because a lot of what he is advocating wasn't...
and maybe will be when we debate. Because as Susan made clear, parenting matters even before a baby is born. Well, we believe very strongly that while genes may provide a blueprint of who your child will become, the house is built. on love. And no matter their polygenic score, which maybe we'll hear more about, or their genetic propensities, or something I love to say, their single nucleotide polymorphisms, children thrive in an environment of relationships.
particularly their attachment with the people who are likely to love them the most, their parents. Robert and Stuart love big numbers. Believe me, Robert's book is full of really impressive statistics. And what they tout, and actually Robert referred to this, is that genetic studies are reliable and replicable, unlike the environment.
which is unstable and largely unpredictable. Exactly. Life is unsystematic, idiosyncratic and serendipitous. Or maybe as they say outside the ivory towers of King's College, shit happens. But... When life deals children a challenging hand, we will argue that it is the loving hands of their parents and their carers that matters the most.
And on a related point, Robert asked earlier, well, why are children, even environmental siblings, that is, children who are adopted and then compared to biological siblings in the same family, so different if they have the same parents?
Well, having the same parents doesn't mean you experience the same parenting. I'm sure those of you who have more than one child will remember that baby number one, if the dummy fell on the floor, you boiled it and sterilized it. And by baby number three or four, he was lucky if you so much as licked it off before you popped it back in his mouth. Parental relationships are not static. They change and they evolve, but they always matter.
Finally, we believe that, Robert believes, that the genetic genie may be out of the bottle. But that encouraging parents to rely on polygenic scores or on what they can learn about their child's genetic scores in shaping their children's futures is absurd. So let me start with our central point, that DNA may provide the blueprint, but that the house is built on love. How many of you are parents? Okay.
I would say most of the audience. So I want you to imagine a time when you were engaged with your baby in some kind of face-to-face interaction. Maybe you were feeding her or bathing him or just playing. And your eyes meet and you gaze into your baby's face and your baby coos or gurgles or smiles and you say, oh, hello there, you're happy today, what are you trying to tell me? And your baby responds by cooing or smiling or...
dribbling some peach puree down her chin. This is what we call a serve and return interaction. It's like a tennis game. And it's unbelievably important in building those neural pathways that Susan described earlier. And we know this because neuroscientists can now look at the electrical activity in the brains of young children when they're fully awake and interacting.
with others. And we also know what happens when young children do not get this kind of serve and return interaction or attention or responsiveness. Babies raised in environments of stress or deprivation and they're not outliers, will show far less activity in key areas of their brain, particularly the prefrontal cortex, which is the kind of air traffic control center of the brain, that's critical to social-emotional development and learning.
Relationship build the brain in other ways. If you imagine a time, let's say a less happy time when your child's... having a meltdown in Waitrose or screaming from his cot at 3 o'clock in the morning, and you respond. When you do that, you provide a sense of security.
a buffer from stress, and you send the critical message, it's okay, I'm here, you can trust your environment. And as hundreds of studies have shown, children who are blessed with positive, healthy relationships with their primary caregiver... are better able to read other people's feelings and able to control their own. They are able to cooperate, to form friendships, to experience increased self-confidence and to learn.
So Robert and Stuart can make a very impressive case for the heritability of intelligence and school attainment and also a host of psychological problems. They use an example from Robert's book, and I quote, What if you found out that one of your children has a low... score for educational attainment, which is quite possible, regardless of how high your apologetic score. It makes sense to go with the grain rather than against it.
He then advises that you cut your losses and not waste money on higher education that doesn't suit them. So let's imagine parents are told when their child is two or three or eight that little Rupert is just never going to pass as GCSEs. Why wouldn't they just shrug their shoulders and say, what's the point of reading them books? In fact, why don't we just take them out of that lovely...
school and get him some vocational training fast. Well, I would argue that whatever these parents are going to save on educational fees, they're going to pay for in Rupert's therapy. And actually, I'm not joking because labels are limiting, they're unhelpful, and they're hurtful. And it's particularly wrong to label children. It's wrong to label anyone based on apologetic risk score that has very low level of predictive power. that the current scores can generate.
And finally, the other side of the House asserts that genetics are not antithetical to equal opportunity. Stewart alluded to this. Quite the opposite. They say that if we control for environmental factors such as privilege and prejudice, genetic differences...
will account for more of the variance in school achievement and employment. Well, that does sound fair. But according to a recent article in the New Statesman, we are living in a country where income inequality is the highest of any European nation.
gap between the very rich and the very poor is the largest of any industrialized nation in the world other than the U.S. And the last time I checked, we were heading in the wrong direction. So are we really meant to believe that socioeconomic status The health and well-being of parents has no impact on children.
What about that little girl who might have apologetic score would predispose her to loving books, as Stuart was indicating? What is she supposed to do if her parents can't afford to buy books or if she's going to school hungry every day? So in summary, we believe that parental love matters, especially in the early years when it shapes the brain. Genes matter. But even if they account for 70% of a trait, like intelligence, the remaining 30%... can't make 100% of the difference.
And last, encouraging parents to rely on genetic data to guide their child-rearing practices, which is what is being advocated by the other side, is ludicrous because you cannot draw a direct line from genes to behavior. especially for something as complex as intelligence. So in concluding, I would just say rather than advocating the use of children's genetic data by parents or educators, why don't we invest in programs that are proven to give children the best possible...
start in life and support their parents, especially those living in challenging circumstances. I urge you to vote against this motion. Thank you. This episode is sponsored by Indeed. You just realised your business needed to hire someone yesterday. How can you find amazing candidates fast? Easy. Just use Indeed. When it comes to hiring, Indeed is all you need. Stop struggling to get your job posts seen on other job sites. Indeed, Sponsor Jobs helps you stand out and hire fast.
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Silly bookers, send us a postcard from the queue. Stop booking around and visit onthebeach.co.uk Pantapitch! Well, this is a very exciting moment in the evening. First of all, I should say thank you very much, all of you. Those were totally compelling. We're at a very exciting moment in the evening because we have the results of the initial vote. You voted when you came in. And what's lovely is that Robert and Stuart have some work to do because...
for the motion was 17% at the start. Against the motion was 66% at the start. So even if you convert... The 17% undecided, you still don't have enough people. So you're going to have to drag some people who really believe that parenting is important and persuade them that it's not, which is lovely.
We would like very, very quick rebuttals, if you don't mind, but if you could really limit it to a few quick, focused remarks, just to rebuttal anything that you want to get to, and then I'm going to give you the opportunity, and then we will throw it open to your interrogation. Okay. We're in the middle of right now in science what's been called the replication crisis where there are many, many studies that are published with tiny samples with...
incompetent statistics with some fraudulent, some biased in many ways. This has been shown very clearly. And unfortunately, the world of human transgenerational epigenetic inheritance is one of those areas that has an awful lot of very small, very inconsistent, very biased.
We're not at the point right now where we can conclude anything about transgenerational epigenetic inheritance in humans. Now, it definitely does happen in plants, and I believe it happens in worms as well, but the evidence in humans is extremely weak. And so...
Stacking that kind of stuff up, the epigenetic stuff up, against 100 years of really solid behaviour genetic evidence, it's really weak. I'm keen to get to the question. Do you want to add a couple of things? Annie was going on about the polygenic scores. You noticed I didn't mention that.
That's the second half of my book, and I thought in 10 minutes I would focus on the first half, which is about the basic twin and adoption research that shows the importance of genetic influence. But it is very exciting that the DNA revolution is beginning to find
some of the DNA differences that account for heritability. But you shouldn't really turn that around to say, oh, you're only explaining a tiny percent of variance with these polygenic scores. I think the point for us about parents making a difference or not has to do with those twin and adoption studies.
that have collected data over a century showing that genetics accounts for about half of the difference, which means the differences, but half of the differences are environmental, but it's not those shared family environmental differences that we call nurture. include parenting. Susan are you happy to offer your rebuttal? I want to say that I am a clinician and as a clinician I have seen many many people.
who have suffered from mental ill health. And I know, and I'm working with mothers in the postpartum and in pregnancy. I want to give one message that these are not outliers. And although we talk about adverse childhood experiences, actually, I think if I asked you to raise your hands and I gave you the list. which I won't do, but you can find it online. I think that, as I said before, most people will say that they have suffered at least one. We are not outliers. I'm not an outlier.
And working with women clinically has shown me that we actually do need to support them. We can't leave it to their genetics. And if I have one message... to give to the government. It's that we recognize the importance of the pregnancy period and that we give mothers and fathers maternity and paternity leave in pregnancy as well as postpartum. Thank you, Susan. Anne.
I guess I would just say that the idea that you're not saying that genes are deterministic is belied by the title of the book. If DNA is a blueprint... then you don't have a blueprint for a house and then end up with a boat. The implication is that... Genes do make us who we are. That's basically the message of your book. And I think that what we really have to keep in mind is that as you showed on that graph, that, and I'm not a...
geneticist, but what I did learn from your book is that when we talk about heritability, we're talking about populations. We're describing populations and differences within populations. Is that right? So we're not really talking about individuals. But parenting, we don't parent variables. We parent people. And there's just so much. I, of course, agree with you that...
we shouldn't force children to be something they aren't. But actually, saying that there's a 70%, you know, you can look at their intelligence scores and it's a 0.7 that they're not, let's say, going to be as clever as you'd like. and then actually labeling them not so clever is really bad parenting and is going to have a very negative effect on children. So that...
That's the difference. Yes, working with what's good about them is great. But I think it's naive to think that being labeled in a family as the not-so-clever one is not going to have a really bad outcome for children. Perfect, Ed. Thank you. So, for me at least, it's boiling down to do I want the stress-free life of someone who's been relegated to the role of chauffeur, security guard and chef, or am I prepared to sign up to the overwhelming...
responsibility that what I do day to day might actually have some serious and profound consequences for my son. The most important bit is your questions. I have loads of questions, but we're going to throw it open to the floor. Can we get number two here? I'd like to ask the against team, by what mechanism do you think post-birth parenting predominantly works? Is it through molding neuroplasticity or is it by influencing gene expression?
And for the pro team, I'd like to know, have either of you tried to account for epigenetics in any way and the influence of the microbiome and the immune system on gene expression? Oh, lovely, meaty questions. Thank you. Number three. Thank you. I have two adopted children. Both of them received no love, no attention from in the womb until they were two.
But I think you can expand this to other children. Unfortunately, lots of children do not receive love and attention in the first two years of their life. So my question for the panel is... Are they doomed because they never got the nurturing love they needed to get at the beginning? If I got lucky with the lottery of their biological children, I'm just fine and I can relax because if they got good parents, they're going to be superstars. Fantastic.
An amazing range of questions there from the deeply personal. This is hugely important. There's a lot at stake to the very specific scientific mechanisms and the intuitive role of what our parents do for us. Can I this time start with Susan and Anne?
Well, actually, two of you have asked two really important questions. This issue of sort of neural molding and how much after the baby is born. I mean, the brain is incredibly plastic in the first few years of life. So I would say to you that actually what you are doing with the baby...
no matter what kinds of early experiences they had, will make a huge difference. We see this from things like the Romanian orphan studies, and these are controlled studies where the children who were put into foster care after they had been institutionalized for...
few years were almost indistinguishable from children who had grown up in homes that had not been adopted. These are the kids who were institutionalized at, you know, 200,000 of them were in institutions in Romania. So there's lots of evidence that shows that what you do...
as a parent makes a big difference. And I would say that that's in response to your question. There's no question, and I'm sure Robert and Stuart would agree that there's plenty of evidence that what we do as parents makes a huge difference. That's really our point. I would say that the...
interest question is very important. I think, you know, how you are raised, what God you worship, doesn't that have an effect on who we are? That has nothing to do with genes. And there are lots of other things that make us who we are. have nothing again to do with our genetic propensities. Can I just add that actually the issue of forcing children to do things, this is not good parenting. And we would all agree that we don't want to force children into doing things that they don't want to do.
Well, maybe sometimes. But the whole interest thing is really important. And as parents, we should look at our children. and work with them in that relationship to determine what is in their best interests and work together in that relationship. So I feel like we're getting a very strong case that there is a sort of intuitive experiential belief that from what sports we play to where we worship.
is deeply shaped by our parents. And those are things that we feel quite profoundly about. Can you respond to some of those issues and maybe also the scientific questions? I'd like to first speak to the Romanian study because that's done by my colleague, Professor Michael Rudder. And that is way out of the normal. range of .
I mean, those kids weren't even touched by people. They were left alone, you know, in soiled diapers. It's the worst. I mean, you'd be arrested if you did that as a parent. But the point that he's made after all these years is those kids have turned out pretty well. well, despite that horrendous first two years of life. So it seems to me it goes against your argument.
But no, but that's because of the ones who've done pretty well are the ones who were given opportunities to be moved into foster care, not the ones who stayed in the institutions. And in fact, the point is that because they were... This was a natural experiment. Thank God we don't have too many of those. But the indications were that these children, because they weren't loved, they were fed. Many of them were fed and clothed. But what was missing was love. And it caused major...
problems on all levels, physical, emotional, psychological, and cognitive. Can I just mention the epigenetics and microbiome thing? There are fads in parenting, and there are fads in science as well. And those two are our current fans in science. I think... It's completely fine to look into that stuff. That's really important. But we do not have anything like the level of clear data on epigenetics, microbiome, and all that stuff.
than we do on behavioural genetics. The question was then, is there a mechanism of post-birth parenting? You're saying no. It's not that I'm saying no. It's them saying we don't know yet. And we shouldn't be afraid to say in some scientific questions, we don't know. And I also don't think we should overstate the case and hype up the case for things like epigenetics. Because we really don't know the answer yet. And there's an awful lot of hype. science.
I would disagree. And we need to stop piping things up. Number one. Stuart, you mentioned about the studies of children with conduct problems, and you'd said, obviously, there is some evidence there that kind of supports that that makes a difference. So that would be working with parents, teaching them to do things like one-to-one time, prayers, putting in place consequences and boundaries is what things that people traditionally think of as.
Good parenting. And I was just wondering what your thoughts were regarding that. Number three. Hello. I'm sure I'm not the first to observe that the two speakers for the motion are male, and the two speakers against the motion are female. And I'm just wondering how much of this is to do with the fact that... And this is a gross generalization, but traditionally, women or mothers tend, and I'm very careful with that, tend to be the more nurturing parenting roles.
I think you phrased that question very elegantly. And if you hadn't asked it, I would have done. Thank you. This is a difficult topic, very sensitive for many people and I'm very grateful to all our speakers for handling it so sensitively. Robin Stewart, can you start... may respond to the working with parents, the one-to-one things, but gender and outliers seems to me, I'm particularly curious about the gender one. we seem to have genes that make us believe that we matter as parents.
even if we don't. So I wonder if you could respond first of all. To which question now? Well, if you can gather up whichever bits of response you want to offer us. Well, we tried hard to improve the gender balance. At least it is two males and two females and then Zan. and none of us can help our gender. But, you know, I'm a parent. I have five kids, depending on how you count. So, I don't know. I mean...
How much of the variance is explained by gender in terms of nurturance and loving your children? I would not be very pleased if someone told me, because I'm a male, I can't love my children. But do you think maybe men care a little bit? Men want to believe that they are less influential parents than they might be. I feel more drawn towards your, but possibly because fatherhood is different to motherhood.
I don't know. It goes beyond the question of genetics, though, doesn't it? Hopefully people can respond to our... Hopefully people can respond to the points we're making with a rational analysis of the scientific points that we're making rather than whether we're male or female. Hopefully we're beyond that.
We do have time for a couple more questions. Thank you. One thing that would be helpful is if you guys could each kind of tell us what you define as parenting, because it seems like the foreside is saying parenting is don't contort yourself with, you know.
all these extra things like the latest fad parenting, whereas the against side is saying don't neglect your children. And I think everybody might agree with that. It would be helpful to say what are you talking about when you're saying parenting matters and it doesn't matter. Thank you very much. Lovely. And number three. Thank you. I had a question for...
Anne Plachette Murphy, you said, and I think I'm quoting, what we do as parents makes a huge difference. If that's the case, how do you account for... these research findings from these twin and adoption studies we've heard quite a lot about this evening, if it's true that what we do as parents makes a huge difference, how do you account for the fact that siblings raised in the same household...
are as different as siblings raised in different households. You said it's because when we parent even siblings in the same household, we treat the siblings slightly differently. Yes, that's probably true, but we can't possibly treat them as differently as an entirely different set of parents. would treat two siblings separated at birth. So how do you account for the fact that not only...
Two sibs brought up separately. Arrows different to each other as two sibs raised together. But more importantly, and neither of you have addressed this, how do you account for the research findings of all these twins that have been brought up?
separately, separated at birth and brought up by different families, they turn out to be, it turns out, almost identical in spite of being raised differently. If parenting makes such a big difference, which you seem to think, and that's your side of the argument, how do you account?
for these research findings. We're going to get there. It's good. I tell you what, for those of you that think this is a false dichotomy, sitting in my chair, I can feel the heat coming off each side. It is not that at all. So, first of all, defining parenting. I'd love to hear from everyone on that. Then talk about peers. And finally, we'll come to your specific challenge there. Can we start with you two defining parenting? Anyway, we...
I've studied parenting in many different ways. Observational studies, videotaped interactions between children. So I've used all the methods to study parenting that anyone has used. I've had large-scale studies with... developmental psychologists, etc. So I'm defining parenting in terms of the measures that people are using. There's two major factors. You know, it's a warmth dimension and a control discipline sort of factor. So we're just using measures that...
other people use and call parenting. And in terms of peers... Oh, sorry, did you want to... Well, I'd like just to add that there is no word. Well, there is now, but the word parenting doesn't exist, in fact. There isn't a verb to parent, if you look back in the English dictionary in the past. And actually, it rather negates the meaning of a parent who is actually a man or a woman in an undeniable relationship with a child by reason of a biological fact.
And I think that I personally would want to call that parental care and not parenting. The last question was specifically about that there does seem to be, and maybe it's literally that I'm a little bit familiar with, just because I'm a twin, I hear it a lot, that... There are these examples and data sets that really seem to suggest that raised in wildly different environments, individuals can turn out very, very similar.
How do you account for that or how do you respond to that? First of all, the number of situations like that documentary showed are very rare because it's not done anymore. We don't separate identical twins and have them adopted. other families but when we do look at the twin studies again what we're seeing and this is probably why we're not disagreeing very much is that it is both I mean we're not saying that you're a blob of clay and that only thing that influences you is you know
is your parenting. But in fact, the reason that kids are different in families is because A, they're different when they arrive, and B, I would argue that parents' relationships to number one, two, or three are very different. Someone's point, you know, children raise their parents as much as parents raise their children. Susan, you had a comment about men. Yeah. Yes, I... Batters are rising.
Really in response to the person over there that said she'd noticed that there were two women on this side and two men on this side. So I just wanted to say that, well, I wondered whether it was something to do with the fact that... that men feel that their role as a parent ends at fertilization. And I want to say to you men out there, you've heard the arguments, your children need you.
more than just your genes. And they need you. We need you as mothers, and we need you, and you are as important as the women. So please, don't feel that we're ignoring you. These events are not called Intelligence Squared for no reason. Let's call her number one. Hi. Can you tell me how much you think... parenting matters in percentages from each side fantastic that's lovely thank you that's a lovely queer clear clear question um so quick responses starting with robin stewart
Okay, 50% of the variance is not genetic, it's due to the environment. But how much of that is due to specified parental effects? I can come up with a few cases where it's maybe 10%, but on average I'd say it's less than 5%. Less than 5%. That's a fantastic question. Great. I thought you've already voted. Can I throw?
Five and a half. Just a slightly bit of... These things differ across the lifespan, so there are larger parenting effects earlier in the lifespan for something like intelligence than there are later. And as Robert said, there are some traits that have larger effects than that, so things like education.
has a larger shared environmental effect than something like intelligence or height or something along those lines. Psychopathology. Or indeed psychopathology, yeah. Lovely. But we've got 5%. Do you want to give a number? I'm afraid you're not going to get a number out of me. I think it's a false dichotomy. I mean, obviously genetics is important and it accounts for a lot. But I think that...
Of course, the epigenetic effect is affecting the gene. So I don't think that we can quite, I can give you a percentage. I don't know. Can I push you for number N? Well, yeah. I mean, I would say just the opposite. I would say that parenting accounts for probably a huger percentage. Or if I put it another way, I think it's that 80-20 rule. I mean, if something can be explained by 80% genetically...
disposition accounts for 80% of a particular trade. To me, the 20% can make all the difference. It's not that you can't weight it equally, in my opinion, in terms of what matters as far as the quality of a child's life. I mean, and I would only say that if you like... the research, and it sounds compelling, buy Robert's book, but don't support the motion. That's great. That's very disarming.
So the moment of truth. What's very nice about this result before I announce it is that everyone gets a bit of a win. So... Remember, in the pre-vote, for was 17%, against was 66%, and don't know was 17%. So in the final vote, for was 29%. So you've dragged quite a few people up. I mean, you've almost doubled it there. Against dropped a little bit, but you did carry the day with 51%. And don't know, we've slightly increased the amount of confusion. To 20%, which I think is lovely.
Can I thank you all for staying so late, for asking such brilliant questions, and can you once again please thank our amazing speakers.