Alana on Judith Rich Harris's "No Two Alike"

In this conversational YouTube interview, Michael Strong guides Alana through a two‑part summary of Judith Rich Harris’s book No Two Alike. The central problem Harris tackles is why genetically identical twins can develop markedly different personalities. Harris proposes a three‑module explanation: the relationship system, the socialization system, and (in part 2) the status system. Michael and Alana first clarify the twin problem, distinguishing identical from fraternal twins, and then explore the first two modules. The relationship system is described as a brain‑based “map” that stores individualized data about each person we encounter, allowing us to recognize and react to them uniquely. The socialization system emphasizes the dominant role of peer groups and broader cultural environments over parental influence in shaping personality, echoing Harris’s earlier work The Nurture Assumption. Throughout, Alana relates these concepts to her own life: being homeschooled, training in jiu‑jitsu and wrestling, and navigating peer groups that differ from typical public‑school experiences. They discuss how peer influence can affect speech patterns, discipline, and values, and compare the intensity of peer pressure at different ages. The conversation also includes thought experiments about twins raised in divergent environments—one thriving, the other failing—and the classic “separated‑at‑birth” twin studies, probing how much environment versus genetics matters. The dialogue ends with plans to read part 2 (the status system) and a mutual expression of interest in genetics, psychology, and child‑rearing.
Chapters
Um, so it's been a little while. I sent you the review or summary of, uh, Judith Rich Harris's book No Two Alike. It was part 1 of a 2-part review. Um, yes, did you get a chance to look it over recently?
I did, yes. It's really interesting.
Good, good, good. I thought after starting with Richard Dawkins' The Selfish Gene, that was kind of abstract and complex and required a lot of knowledge of genetics and so forth, I thought this is more kind of concrete and immediately relevant. And so I thought it was another entry point into the whole topic of nature versus nurture. So I'll pause just to get your first reflections. What are your thoughts on this article and her ideas and so forth?
Okay, so there was a couple different points, but I feel like they're all a little similar. And I think I like the general idea of it was how you treat— well, actually there were two— how you treat people based on their personality and your like individual database of different people, I guess. And then the second one was individualized personalities, and I know they were talking about twins versus regular siblings. Uh, with the twins they were saying that they're obviously going to be more alike, at least physical, because they have more traits— or I mean more genes similar genes because they were twins, right? Whereas regular siblings like me and my brother who aren't twins have less genes, so maybe we'll still look alike, but we won't look as much alike as the twins, and maybe we'd have even more different personalities. But they were also saying that in twins, even though they share like whatever, like 90-something percent of their genes, it's also possible that they have completely different personalities. And I know that there were— there was one or two reasons. One of them is which is the environment, and I know the genes had something to do with the personalities, but I couldn't quite understand what. I think it was because— yeah, I didn't really understand that part, but I know that the genes definitely affect the physical traits but not really the personality. And then the other big part for me was how They said that each person has like a big map or web of data that they like place with each person in their life that they know. Like for example, I can recognize my— I recognize my friend not just because of her physical attributes, but also my brain like remembers our interactions and how I feel about her individually. And it does that with every single person that I've met, at least the ones that it wants to remember. And I thought that was interesting because I actually feel that sometimes, especially with one example, like one of my friends. Some days I'll have like a lot of fun with her and then some days I'll be like, like, what are we doing? And then the next time, depending on how I interacted with her, is how I'll feel about her. I guess, does it make sense? But those were the two things that I thought were really interesting. There.
Got it. Um, let me back up. Thank you. Let me back up a little bit first. Um, to be clear, there are— quite aside from this article— there are two different kinds of twins, actually. Um, there are identical twins, which do share the same DNA, the same genetics, and then there are fraternal twins that are more different. And so it depends on exactly how the twins are formed in the mother's womb. But sometimes, going back to your point about identical twins, do look almost identical. That's why they're called identical twins when you look at them. But there are some twins that actually look very different because they actually don't share completely the same genetic material. So, and we're here, she's interested in the question of why is it, or how is it, that identical twins that do have the same genetics, you know, in say '98, '99, almost completely basically the same genetics, how can they have different personalities? Because one belief might be, hey, because they have the same genetics and the same physical characteristics, one might have expected that they would have the same personality. Turns out they don't. I'm sort of just clarifying, I think, some of the things you were saying. Does, does that framing make sense as the problem she's trying to solve?
Yes, for sure.
Okay, great. So in which case, so that's the problem she's trying to solve. And then she has 3 modules and you were referring to 2 of the 3. The third module will come in part 2 of the article. But basically she has a 3-part explanation for why is it that people with the same genetic traits, identical twins that is, could have different personalities. And she calls, she calls them in this article, the first 2, the relationship system, the social and the socialization system. And then the third article, the third one, I think, which is the next article we'll talk about next time, is the status system. So just wanted to clarify, problem is why do identical twins have different personalities? Solution, according to Judith Rich Harris, is relationship system and socialization system, plus this other thing that we'll get to next time. Is that clarification helpful?
Yes, for sure.
Okay. In which case, now that we've got all that framing down, um, yeah, let's dig into the, what she calls the relationship system. How are you understanding that again?
I might have mixed up the names, but I believe the relationship system is how your brain remembers and stores the data that you have with each individual person that you react with. And in the individual twins, those might be different.
Yeah, that's basically right. And so I guess I always like sometimes when scientists or where anybody is solving a problem, it helps to get clarity on the problem they're solving. Because before I read this, for instance, I sort of took it for granted. Of course I recognize Alana. Of course I recognized her father. Of course I recognize Ms. Karen. That is, I think we take it for granted that we recognize other people. But just thinking of other things, do fish recognize individual human beings? Probably not. Do flies? Yeah, I mean, dogs do actually. Dogs, and that's interesting because I, at least I believe dogs recognize individual human beings. Do you think dogs do?
I think so. I mean, how would— I mean, if they don't, then how would they recognize their owner and be so happy with them, right?
Exactly. And at least in dog's case, maybe much more by smell than by sight and sound and so forth.
Although I smell a lot of different things though throughout the day, so I don't know.
Exactly. And I think humans do recognize each other to some extent by smell as well, but dogs much more so. I've heard dog smell is like 1,000 times more powerful than humans or something. Just maybe I'm exaggerating, but a lot more, undoubtedly. So yeah, part of the mystery she's solving with this relationship system is, hey, you know, We shouldn't take it for granted that people can recognize each other. Um, we must have a brain module, so to speak, that allows us to recognize each other. Um, and yeah, I, I don't know what else there is to say, but is it interesting, or now that you think of it as a problem, does it, is it kind of interesting that in fact you can recognize different people in different ways and all of that?
Yeah, it is for sure. And after reading that, yeah, it was like, I felt that I definitely took that for granted before, but now that I kind of understand it a little bit more, I can think about it.
Yeah. And by the way, you know, when I was young, I absolutely remembered everybody I met and pretty much everything I said to them and all of that. Now I've met so many people, sometimes, you know, many, many thousands. Sometimes I forget that I've met someone and it's a little bit embarrassing. Somebody approached me at a conference. Oh, Michael, so good to see you again. I'm like, Oh no. But, and by the way, I've heard that politicians, like some politicians are really good at remembering large numbers of people, like thousands and thousands. So yeah, I want to acknowledge that we all have this relationship system. And at least personally, I'm kind of beyond my numbers because I meet so many people at conferences. But yeah. I'm going to then go to the socialization system, which I personally find a bit more interesting. What's your summary of the socialization system?
So this one was a little bit harder to wrap my head around. So if I mess it up a little, my bad. But I believe that the socialization system is where it is, like the interactions between people and like the environment that just, for example, the twin is grown up in.
Sorry. Totally. Totally. But I want to add a little bit. And part of this is Judith Rich Harris's first book, The Nurture Assumption, which is summarized briefly at the beginning of the article, was all about how peer environment is typically more powerful than parents in upbringing. And so some people— and I want to dig into your personal case in a minute here, but Some people believe parents mostly form. So one way to think about it is what forms human beings. There are genetics, there are parents, there are peer culture, there's broader culture, you know, there's education, there are all the decisions you make as an individual. There are all these things that form you or me or whomever. But her first book was basically, wow, peers are so much more influential than parents, especially for teens. Um, yeah, and she uses— or this article uses the example of if, say, a Chinese-American family lives in Minnesota, the parents can try as hard as they want to try to get the kid to have a Chinese accent, Chinese-American accent. Odds are, oh yeah, right, from a young age they're just gonna have an American accent because, you know, you know, kids talk the way other kids talk. So I'll pause there. Does all that make sense?
Yes, for sure. Okay, go ahead. Oh, sorry, I was just going to say that, uh, yeah, I think that's true, because especially if you think about kids who are in public schools, I mean, they've spent so much time in school or outside of school with like their friends and other people their age, um, especially, yeah, as you get older, like teenagers So it just makes sense.
Yeah. Well, although, you know, you also spend a lot of time with parents and I guess you are an unusual case in that, is it fair to say that, I mean, when you're at TSC, you have TSC relationships, you have some peer, you certainly have martial arts relationships, but would you say you're not as immersed in peer culture as say public school kids are?
I guess not, because I'm not in school for 7 or 8 hours a day, but, uh, I'm still, you know, doing school, going to jiu-jitsu or wrestling, and hang out with friends there, like meeting up with my friends and hang out and doing all the things that normal kid would, except not stuck in a classroom. I guess there might be a little less because I'm not in that classroom, but not too much.
Would you say that peer relationships are as powerful as your parents, or more powerful than your parents, or in your case, do you think more less powerful than your parents?
I think, uh, in my case it's kind of even because I spend less time than with my peer group and friends and other people, and I spend more time with my parents than other kids as well. Um, so I feel like especially in my case I might have a deeper relationship with my parents than some of the, some of the other kids I met. Some of them have a good relationship with their parents even though they spend lots of time in school. But in my case, since our relationship is deeper and maybe we're more like friends than other kids in my classes and schools and stuff are, they might have a more positive and just bigger impact on me than they would have if I was in regular school.
I think totally makes sense. Another question I have kind of out of curiosity is there is kind of a standard expectation that a teenager is— peer pressure is even more intense as a teenager. Since you're just becoming a teenager, do you have any sense as to whether kind of— and instead of calling it peer pressure, just peer influence— do you think peers are having more of an influence on you now than they did, say, 3 or 4 years ago when you were younger?
Um, I think it depends on what you call peer pressure. Like, peer pressure as in, like, influencing my actions or my speech or whatever. Because actually one of the things I noticed about myself is that especially when I'm hanging out with people who are older than me, which I do a lot because of martial arts and wrestling and things like that, is that I tend to pick up on other people's speech patterns. Like this girl that I live with and train with, she's like a lot older. She's like 19, I think. She'll like say all these different things, probably from like social media or whatever, and I'll spend so much time with her that I'll start saying them too. And I'll catch myself doing that one thing and be like, oh my gosh, because that's not from— that's not just mine, it's hers, right? So it feels a little weird, but I haven't really been in a case where they're like, or where my peers or friends are like, oh, you should do this, you should jump off a cliff, like peer pressure, you know? So maybe later, but not now. I feel like that's the biggest case that I felt, and it's still kind of small.
No, no, that makes sense. And by the way, I remember when I was young, I would start, especially people like with a British accent or an Australian accent or Scottish accent, I would start, you know, not quite imitating, spontaneously speaking as they did, and then I became self-conscious about it because I didn't want them to think I was making fun of their accents.
Oh, yeah.
So I'd kind of deliberately, "No, speak American." But I had a natural spontaneous inclination to speak, and I think we all do to some extent, but some of us more than others.
Yeah.
Earlier you were talking about how you thought maybe public school kids are more influenced by peer culture. Can you say more about that? What are the signs? What is the evidence? Or in what ways does it seem as if public school kids are more influenced by peer culture?
Um, I was just saying that because, I mean, on a really, really basic level, they spend more time— well, you could say they spend more time with their groups than their parents, just because they're around them all week in school and outside of school too, with people hanging out outside of school too. But, um, that was my main point in school. Especially if your kid is like really rebellious and they might want to hang out or act like their peer group instead of listening to their parents, right? Which I'm sure everyone experiences at least a little in their life. But the reason why I just said public school is because they're surrounded by their peer group and friends more than homeschooled kids might be. Most homeschooled kids are just at home all day I feel like my brother and I are kind of the rare exception where we homeschooled because of jiu-jitsu and wrestling mainly. Not, um, that's not the whole reason, but, uh, so we get to go out and interact with other kids and our peers more than other homeschooled kids would be. Um, yeah, so that was my point.
Um, so it sounds like no direct observation, it's more kind of expecting that public school kids would be more influenced.
Yes. And the reason why it's not more direct is because I haven't, or is because most of my friends are homeschooled.
Got it.
Because we're all like training in the morning and like on a schedule and to be on that schedule, we have to be homeschooled. So yeah.
Got it. And by the way, insofar as first jujitsu and wrestling, it's all about discipline. And my expectation is that the peer group, that particular peer group, especially if many of them are older, is actually probably a really positive set of peer influences because I would expect insofar as there's peer pressure, it's peer pressure to be more disciplined and to train more and to be more focused. Is that roughly correct?
Yes. That's actually one of the things that my dad would always talk about when he was like promoting different things, you know, him, right? He would, he would highlight how, well, first of all, the kids in like wrestling and jiu-jitsu academies tend to be focused, positive, not bullyish, like just all around pretty good kids. Of course, that's like, there's exceptions, but that's like kind of the main thing. And because there's so many ages mixed together, you could have like a 7-year-old in the same class as like a 14-year-old, right? Just because they're so, or they're like in the same class, the 7-year-old is influenced by the 14-year-old, even if it's in a small way. And because most of the kids are positive and, you know, good kids, then the 14-year-old rubs off on the 7-year-old. And that wouldn't happen if it was just a class of 7-year-olds, like age group baseball or something where the kids are kind of all the same age, or soccer, whatever. Doesn't happen as much. And even if the jiu-jitsu wrestling class is kids around the same age, right? Again, there tends to be that demographic, especially in jiu-jitsu, in my opinion, where, uh, like, the kids are pretty good kids. Everyone rubs off on each other. And of course, like I said, there are exceptions, but I feel like the good outweighs the bad in most cases.
Totally, totally. No, makes a lot of sense. And then, um, now we're ready to kind of get part of Harris's explanation for why identical twins might differ with respect to their personality behaviors. And, you know, again, out of the three systems, we've got the relationship system, we've been discussing the socialization system. Next time we'll read about the status system and discuss that. But just on the relationship system, you remember the anecdote in this article about identical twins, one of whom grew up to be a successful businessman, the other was a homeless drunk on this— on the street? that's sort of an extreme case. And so one way to think about this would be, and I'm going to exaggerate, I don't want to be too mean about public school, but suppose you had identical twins. There's an identical Ilana, you know, exactly the same DNA. She looks just like you, but you're in the jujitsu thing and she went to the worst public school and had the worst friends. And her friends— I know, maybe this is an interesting thought experiment. Do you think that if If instead of being jujitsu, Ilana, your identical twin went to the worst school with the worst friend group, that she might have gradually, or be at this point developing, a different and perhaps less positive personality?
Yes, absolutely. And if we're just focusing on like the school group and my peer group, then yes, especially because like you specified, I'd be hanging out with with like bad kids who like maybe aren't focused and aren't doing the right things. I think that would happen, especially if you cut my parents out, because I don't think my parents would let that happen, to be honest. They, especially if my grades were bad, they'd probably like really look into the problem and, you know, change my friend group or whatever. But if there were no parents, yes, I think so.
No, it is. I think it's an interesting thought experiment. And of course, I would like to believe that um, pure Alana could be an amazing person no matter what the environment in which she was raised. But, and in your case, I think you're right. I think your parents are absolutely amazing, and so I think your parents would not let all of that happen. I completely agree. But so suppose you were suffering—
what was happening—
go ahead.
Oh, I'm sorry, uh, especially if it was happening from a young age, because I feel like if I was surrounded by that thing like recently, like 11 or 12, I don't think that I would have gone down that path because I would have been able to recognize that like, oh, these guys are bad, my grades are bad, I gotta fix something.
Yeah.
But if I was in that environment from like first grade or kindergarten or fourth grade or whatever, then it would have been worse.
No, absolutely. And I think you're right. I think you are remarkably strong and resilient, so much so that maybe even, you know, Alana in bad school could have been pretty, pretty much fine. But one experiment psychologists are super interested in is identical twins separated at birth. And, you know, there's sometimes families can afford it, sometimes refugee families, sometimes the parents die and the twins are separated at birth. And so, you know, it's not a perfect experiment about genetics, nature versus nurture, because of course they both were in the mom's womb until birth. And so they had a common shared environment from conception to birth. But suppose hypothetically that Alana and her twin were separated at birth, and one got Alana's current amazing parents and the amazing jiu-jitsu and all of that. But the separated-at-birth Alana was to a family of, you know, alcoholics and drug abusers and bad neighborhood and from birth. So how different do you think that Alana would have been?
It would have been very different. I think I wouldn't be doing— I wouldn't be athletic and I wouldn't be in jiu-jitsu and wrestling and I probably wouldn't have the grades like in terms of school that I have now, or I wouldn't have my friend group and I wouldn't be surrounded by all the people that I like to be surrounded with. So I think it'd be different, probably bad or worse, especially with the bad parents. I think especially at an early age, gotta there, the parents really define who you are. But yeah, that'd be bad.
Um, yeah, not to give you a kind of terrible thought experiment, but, um, so next time let's read the part 2 of this article. I'll send it over, um, via WhatsApp. Um, or in general, would you say you are finding this whole world of kind of genetics and psychology and child rearing to be an interesting world to explore?
Yes, very.
Okay, cool. In which case, thanks. I hope you feel better soon, and I look forward to reading and discussing the rest of the summary of Judith Rich Harris' No Two Alike.
All right, thank you.
You're welcome. Bye-bye.










