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No Two Alike: Human Nature and Human Individuality
"A display of scientific courage and imagination." ―William Saletan, New York Times Book Review Why do people―even identical twins reared in the same home―differ so much in personality? Armed with an inquiring mind and insights from evolutionary psychology, Judith Rich Harris sets out to solve the mystery of human individuality. 12 illustrations
344 pages, Paperback
First published January 1, 2006
About the author
Judith Rich Harris
13 books75 followersJudith Rich Harris was born February 10, 1938, and spent the first part of her childhood moving around with her family from one part of the country to another. Her parents eventually settled in Tucson, Arizona, where the climate permitted her father (invalided by an autoimmune disease called ankylosing spondylitis) to live in reasonable comfort. Harris graduated from Tucson High School and attended the University of Arizona and Brandeis University. She graduated magna cum laude from Brandeis in 1959 and was awarded the Lila Pearlman Prize in psychology. In 1961 she received a master's degree in psychology from Harvard University.
Harris has been married since 1961 to Charles S. Harris; they have two daughters, born in 1966 and 1969, and four grandchildren, born in 1996, 1999, 2001, and 2004. Before her children were born, Harris worked as a teaching assistant in psychology at MIT (1961-1962), and as a research assistant at Bolt Beranek and Newman (1962-1963) and the University of Pennsylvania (1963-1965).
Since 1977, Harris has suffered from a chronic autoimmune disorder called mixed connective tissue disease - an "overlap" combination of lupus and systemic sclerosis. This disorder can affect virtually any organ in the body. One of its more serious complications is a heart-lung condition known as pulmonary arterial hypertension. Harris was diagnosed with this condition in 2002.
While bedridden for a period of time in the late 1970s, Harris worked out a mathematical model of visual search; this work was published in two articles in the journal Perception and Psychophysics (see publication list below). From 1981 to 1994 she was a writer of textbooks in developmental psychology. She is senior author of The Child (Prentice-Hall, 1984, 1987, 1991) and Infant and Child (1992).
In 1994 Harris had begun work on a new development textbook, without a co-author this time, when she had an idea that led her to formulate a new theory of child development. She abandoned the textbook and instead wrote an article for the Psychological Review. Work on The Nurture Assumption began in 1995; the book was published three years later (Free Press, 1998). But the theory continued to evolve. The final version was presented in No Two Alike: Human Nature and Human Individuality (Norton, 2006).
Harris is a member of the Association for Psychological Science and Phi Beta Kappa. In 1998 she received the George A. Miller Award from the American Psychological Association for her article entitled "Where Is the Child's Environment? A Group Socialization Theory of Development" (Psychological Review, 1995). This award is given to an outstanding article, particularly one that makes linkages between diverse fields of psychology. In 2007 she received the David Horrobin Prize for Medical Theory for her article "Parental selection: a third selection process in the evolution of human hairlessness and skin color" (Medical Hypotheses, 2006).
Harris has been married since 1961 to Charles S. Harris; they have two daughters, born in 1966 and 1969, and four grandchildren, born in 1996, 1999, 2001, and 2004. Before her children were born, Harris worked as a teaching assistant in psychology at MIT (1961-1962), and as a research assistant at Bolt Beranek and Newman (1962-1963) and the University of Pennsylvania (1963-1965).
Since 1977, Harris has suffered from a chronic autoimmune disorder called mixed connective tissue disease - an "overlap" combination of lupus and systemic sclerosis. This disorder can affect virtually any organ in the body. One of its more serious complications is a heart-lung condition known as pulmonary arterial hypertension. Harris was diagnosed with this condition in 2002.
While bedridden for a period of time in the late 1970s, Harris worked out a mathematical model of visual search; this work was published in two articles in the journal Perception and Psychophysics (see publication list below). From 1981 to 1994 she was a writer of textbooks in developmental psychology. She is senior author of The Child (Prentice-Hall, 1984, 1987, 1991) and Infant and Child (1992).
In 1994 Harris had begun work on a new development textbook, without a co-author this time, when she had an idea that led her to formulate a new theory of child development. She abandoned the textbook and instead wrote an article for the Psychological Review. Work on The Nurture Assumption began in 1995; the book was published three years later (Free Press, 1998). But the theory continued to evolve. The final version was presented in No Two Alike: Human Nature and Human Individuality (Norton, 2006).
Harris is a member of the Association for Psychological Science and Phi Beta Kappa. In 1998 she received the George A. Miller Award from the American Psychological Association for her article entitled "Where Is the Child's Environment? A Group Socialization Theory of Development" (Psychological Review, 1995). This award is given to an outstanding article, particularly one that makes linkages between diverse fields of psychology. In 2007 she received the David Horrobin Prize for Medical Theory for her article "Parental selection: a third selection process in the evolution of human hairlessness and skin color" (Medical Hypotheses, 2006).
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Displaying 1 - 30 of 40 reviews
October 20, 2015
As a second grade teacher this book has probably had more of an effect on how I relate to my students than anything else I've read. It has freed me up to do what I can to help students become more successful without getting caught up in those things that I can't change: their genetic makeup and home lives.
I refer to it often in talking to parents, along with The Myth of Laziness and a couple of other books.
This book challenges our common thinking, a lot of recent 'research' and culturally accepted viewpoints. Its revolutionary and I don't think that's hyperbolic, close but not quite. Sometimes it is hard to wrap my head around its implications. But I do believe that people are very capable of situational personalities; that they can be very different in different environments. And this book promulgates that view, among others.
It is the most important book I've read as far back as I can remember, and I read a lot of books and really appreciate most of what I have read.
I refer to it often in talking to parents, along with The Myth of Laziness and a couple of other books.
This book challenges our common thinking, a lot of recent 'research' and culturally accepted viewpoints. Its revolutionary and I don't think that's hyperbolic, close but not quite. Sometimes it is hard to wrap my head around its implications. But I do believe that people are very capable of situational personalities; that they can be very different in different environments. And this book promulgates that view, among others.
It is the most important book I've read as far back as I can remember, and I read a lot of books and really appreciate most of what I have read.
November 5, 2021
Este libro continúa la anterior obra de la autora, El mito de la educación. Una vez en el anterior estableció que los padres tenemos una mínima influencia en el desarrollo de la personalidad de nuestros hijos, y que el estilo de crianza da bastante igual, la autora explora el por qué incluso los gemelos idénticos criados en la misma familia son tan diferentes entre sí. Es una lectura esencial que tumba muchos de los mitos en este campo, y por ello necesaria especialmente para aquellos que somos padres.
Me ha gustado tanto como el anterior.
Me ha gustado tanto como el anterior.
June 10, 2022
The author suggests that there are three main factors besides genes and environment (nature and nurture) that influence our personalities: the desire for favorable relationships, the need to be a member of a group, and the drive to maintain status within that group and those relationships. In order to accomplish this, we modify our behavior according to the situation and the people involved.
In other words, your personality is not you. It's the part of you that you choose to show to certain people in certain situations. And your old habits can be changed and modified even in adulthood. Just as the mindfulness community has been telling us, we have control over our own experience. Our interactions and reactions are our own responsibility.
In other words, your personality is not you. It's the part of you that you choose to show to certain people in certain situations. And your old habits can be changed and modified even in adulthood. Just as the mindfulness community has been telling us, we have control over our own experience. Our interactions and reactions are our own responsibility.
February 11, 2020
Good book
An interesting take on why we turn out the way we do. And a welcome respite for parents who seem to be blamed for everything and anything that goes wrong in people’s lives.
An interesting take on why we turn out the way we do. And a welcome respite for parents who seem to be blamed for everything and anything that goes wrong in people’s lives.
December 2, 2022
Judith eloquently proves for over 300 pages why the home environment doesn’t determine the outcome of a child’s life as much as we would like to think.
December 14, 2018
In her first book, The Nurture Assumption, Judith Rich Harris presented evidence and analysis suggesting that parenting styles have little impact on long-term child development. No Two Alike has a different aim but in a way it more convincingly argues Nurture Assumption's case because it describes and rebuts criticism of the first book, and her critics support the factual basis of many of her claims.
The main point of this book, though, is Harris's speculation about what makes people so different from each other. Due to heredity, related people resemble each other in personality etc to some extent. The closer the relation (identical twin vs fraternal twin, sibling vs cousin, etc.) the stronger the similarity. About half of personality differences among people are due to heredity. What causes the other half is often called environment or nurture (as in nature vs nurture), and yet not much of this half can be attributed to anything obvious. Adopted siblings raised together since birth resemble each other about as little as unrelated strangers. More to the point, identical twins who are raised in the same house & attend the same schools resemble each other little more than do twins separated at birth. What causes these people who share almost identical genetic makeup and who live in almost identical environments to differ from each other so much? Harris suggests that the cause may be a reproduction-enhancing drive to specialization, via a status module in the brain. Even twin children in the same social circle would be assigned different roles in that circle & as the twig is bent so the tree will grow.
The main point of this book, though, is Harris's speculation about what makes people so different from each other. Due to heredity, related people resemble each other in personality etc to some extent. The closer the relation (identical twin vs fraternal twin, sibling vs cousin, etc.) the stronger the similarity. About half of personality differences among people are due to heredity. What causes the other half is often called environment or nurture (as in nature vs nurture), and yet not much of this half can be attributed to anything obvious. Adopted siblings raised together since birth resemble each other about as little as unrelated strangers. More to the point, identical twins who are raised in the same house & attend the same schools resemble each other little more than do twins separated at birth. What causes these people who share almost identical genetic makeup and who live in almost identical environments to differ from each other so much? Harris suggests that the cause may be a reproduction-enhancing drive to specialization, via a status module in the brain. Even twin children in the same social circle would be assigned different roles in that circle & as the twig is bent so the tree will grow.
February 22, 2011
Judith Rich Harris, who broke into public consciousness over 10 years ago with her book The Nurture Assumption, has again assembled and analyzed countless studies on personality development in an attempt to answer the question: "What besides genetics shapes individual personality?" While it might seem obvious that the other factor is environment, Rich says not so fast. We tend to understand "environment" as "family environment," above all the way our parents raised us. According to Rich, the best research indicates that it's not the parental environment that counts. Parents do affect the way children act and react--but only in the home. The most enduring personality traits, after genetics are taken into account, coalesce due to small accidents (both in utero and without) and attempts to differentiate ourselves from our peers in ways large and small. This is why identical twins (who have identical genetics and the identical family environment) routinely end up with quite different personalities. Harris invites others to test her theory--whether or not it turns out to hold water, it's a fascinating one, and one learns a lot about personality research while watching her patiently put it together.
August 8, 2019
A masterful presentation of how we become who we are
This is an outstanding book on social and developmental psychology based primarily on evolutionary psychology, cognitive psychology and neuroscience--the new paradigm that's revolutionizing academic psychology. It's engagingly written, authoritative, witty, ingeniously argued, and filled with information and wisdom. Judith Rich Harris is that rare, very rare, individual who is a top academic without a position at a major university, a professor without portfolio, so to speak.
When I first picked this up I almost put it down again. The title "No Two Alike" sounds suspiciously like another feel good, shallow celebration of human diversity. Right. We're all wonderful. Thanks, I needed that. Furthermore, I kind of creeped out at the joined-at-the-heads twins that were the subject near the beginning of the book. In fact I stopped reading from the beginning and put the book aside. When I returned to it, I noticed that chapters six through nine were entitled, The Modular Mind, The Relationship System, The Socialization System, and The Status System. That rekindled my interest.
The idea of the modular mind comes from fairly recent advances in neuroscience and cognitive psychology as understood from an evolutionary perspective. I started reading on page 143 where the chapter on the modular mind begins. What I discovered is that Harris' understanding of who we are and how we got that way begins with evidence from genetics and ends with insights from social psychology. She sees the relationship system as the way we learn to form and maintain relationships with others. The infant begins with a relationship with its mother. Harris states that the child's first job is to get the mother to love her. I have seen this in children and they do it mostly by appealing to the mother's instincts. They are small and helpless with relatively big eyes and soft skin, etc., and so appear to the mother as irresistibly cute. Next they try to win the love of the father. Girls instinctively know that if they win the love of their father they are likely to be safe. They work hard at it. Then come the relationships with others.
And then comes the socialization system. Harris makes a distinction between learning to form relationships and socialization. In the former it's one on one. In the latter we don't so much relate to individuals as to the average of all others. We seek to become like the typical person in our group. We support the group and identify with its values and preoccupations.
Finally comes the status system. This is in some sense at loggerheads with the socialization system. Instead of seeking to be like others, what we want is to be like them only a little better or at least a little better at something. Instead of imitating the styles of others we look at them to read how they rate us.
Harris sees these three systems with our genes interacting over time as forming our personalities. She makes it clear that it is our peer groups that we look to for both our identity and our status. She believes that the primary information we receive does not come from our parents. We adjust to and comform to the values, beliefs and mores of the larger society at the peer group level, not to the values, beliefs and mores of our parents, except insofar as their values are similar to those of the larger group. Furthermore, we tend to discount the opinions of our relatives when assessing our status. (They can be biased!) Instead we look to our peers to tell us how we stand. Harris calls this "mindreading," but what we do is not so much read the minds of our peers as read their behavior, especially their behavior toward us, and deduce our status accordingly. If everybody in the group suddenly turns to look at you when the tough question comes up--guess what? They probably think you are the best person to answer it. When it comes to deciding how to choose up teams for basketball, if their eyes turn to Basketball Jones, you can be fairly sure that they think Basketball Jones knows basketball, or at least she knows how to set up teams.
The complex interactions of these systems in addition to the genetic endowment ensures us that everybody is unique, even identical twins. Harris makes a point of showing how identical twins become differentiated over time through feedback from especially the status system. People need to form mental dossiers on everybody they know, and they do so even with twins; and in doing so they see fine distinctions, and then the distinctions grow. Not only that but one twin will, through happenstance or "environmental noise," as Harris terms it, be ever so slightly more assertive or more confident, and that difference, like a leak in a dike, will grow.
In short this is a terrific book, skillfully and even eloquently written, full of information and deep insights into human nature, well documented and argued in a most convincing manner. It is simply one of the best books on psychology that I have read in quite a while.
Here's a quote from Harris that demonstrates her skill and intelligence: "The desire for status begins early and lasts a lifetime. Old people in nursing homes, well past the point when Viagra can do them any good, still care about their status. In my view, status is an end in itself for humans. The fact that it buys access to desirable sexual partners in adulthood is no doubt one of the evolutionary reasons we are endowed with this motive, but evolution's reasons shouldn't be confused with people's motivations. Status also buys access to desirable things to eat and drink, but the drive to gain status isn't a side effect of hunger or thirst. If anything, hunger and thirst are likely to interfere with the quest for status. Sex can too. Ask Bill Clinton." (p. 256)
--Dennis Littrell, author of “The World Is Not as We Think It Is”
This is an outstanding book on social and developmental psychology based primarily on evolutionary psychology, cognitive psychology and neuroscience--the new paradigm that's revolutionizing academic psychology. It's engagingly written, authoritative, witty, ingeniously argued, and filled with information and wisdom. Judith Rich Harris is that rare, very rare, individual who is a top academic without a position at a major university, a professor without portfolio, so to speak.
When I first picked this up I almost put it down again. The title "No Two Alike" sounds suspiciously like another feel good, shallow celebration of human diversity. Right. We're all wonderful. Thanks, I needed that. Furthermore, I kind of creeped out at the joined-at-the-heads twins that were the subject near the beginning of the book. In fact I stopped reading from the beginning and put the book aside. When I returned to it, I noticed that chapters six through nine were entitled, The Modular Mind, The Relationship System, The Socialization System, and The Status System. That rekindled my interest.
The idea of the modular mind comes from fairly recent advances in neuroscience and cognitive psychology as understood from an evolutionary perspective. I started reading on page 143 where the chapter on the modular mind begins. What I discovered is that Harris' understanding of who we are and how we got that way begins with evidence from genetics and ends with insights from social psychology. She sees the relationship system as the way we learn to form and maintain relationships with others. The infant begins with a relationship with its mother. Harris states that the child's first job is to get the mother to love her. I have seen this in children and they do it mostly by appealing to the mother's instincts. They are small and helpless with relatively big eyes and soft skin, etc., and so appear to the mother as irresistibly cute. Next they try to win the love of the father. Girls instinctively know that if they win the love of their father they are likely to be safe. They work hard at it. Then come the relationships with others.
And then comes the socialization system. Harris makes a distinction between learning to form relationships and socialization. In the former it's one on one. In the latter we don't so much relate to individuals as to the average of all others. We seek to become like the typical person in our group. We support the group and identify with its values and preoccupations.
Finally comes the status system. This is in some sense at loggerheads with the socialization system. Instead of seeking to be like others, what we want is to be like them only a little better or at least a little better at something. Instead of imitating the styles of others we look at them to read how they rate us.
Harris sees these three systems with our genes interacting over time as forming our personalities. She makes it clear that it is our peer groups that we look to for both our identity and our status. She believes that the primary information we receive does not come from our parents. We adjust to and comform to the values, beliefs and mores of the larger society at the peer group level, not to the values, beliefs and mores of our parents, except insofar as their values are similar to those of the larger group. Furthermore, we tend to discount the opinions of our relatives when assessing our status. (They can be biased!) Instead we look to our peers to tell us how we stand. Harris calls this "mindreading," but what we do is not so much read the minds of our peers as read their behavior, especially their behavior toward us, and deduce our status accordingly. If everybody in the group suddenly turns to look at you when the tough question comes up--guess what? They probably think you are the best person to answer it. When it comes to deciding how to choose up teams for basketball, if their eyes turn to Basketball Jones, you can be fairly sure that they think Basketball Jones knows basketball, or at least she knows how to set up teams.
The complex interactions of these systems in addition to the genetic endowment ensures us that everybody is unique, even identical twins. Harris makes a point of showing how identical twins become differentiated over time through feedback from especially the status system. People need to form mental dossiers on everybody they know, and they do so even with twins; and in doing so they see fine distinctions, and then the distinctions grow. Not only that but one twin will, through happenstance or "environmental noise," as Harris terms it, be ever so slightly more assertive or more confident, and that difference, like a leak in a dike, will grow.
In short this is a terrific book, skillfully and even eloquently written, full of information and deep insights into human nature, well documented and argued in a most convincing manner. It is simply one of the best books on psychology that I have read in quite a while.
Here's a quote from Harris that demonstrates her skill and intelligence: "The desire for status begins early and lasts a lifetime. Old people in nursing homes, well past the point when Viagra can do them any good, still care about their status. In my view, status is an end in itself for humans. The fact that it buys access to desirable sexual partners in adulthood is no doubt one of the evolutionary reasons we are endowed with this motive, but evolution's reasons shouldn't be confused with people's motivations. Status also buys access to desirable things to eat and drink, but the drive to gain status isn't a side effect of hunger or thirst. If anything, hunger and thirst are likely to interfere with the quest for status. Sex can too. Ask Bill Clinton." (p. 256)
--Dennis Littrell, author of “The World Is Not as We Think It Is”
July 14, 2014
too much Simon Baron-Cohen; but a good, cohesive theory of personality development
May 29, 2022
I am a massive fan of Judith Rich Harris and reading The Nurture Assumption was life changing. In this books she investigates why we have different personalities starting with the example of identical conjoined twins, who shared genetics and an environment their whole life, yet were different in personality. If it is not our genes (nature), nor our environment (nurture), then what makes ourselves, our selves.
Rich-Harris provides a three pronged theory of the formation personality around the interaction between the relationship, socialization, and status systems. She hoped that others would be interested enough in her work find evidence of her theory as “Someone who thinks up a new theory is the last person who should be trusted with the job of testing it” (p 269). She inconveniently she died before anyone could do any work to prove or disprove for her theory. I found her theory plausable.
Rich-Harris also states “One of my goals in writing this book was to give you a healthy skepticism in regard to research. Researchers are human; they make mistakes; they have their own hopes and needs, their own beliefs. Doing research is a lot of work and is seldom carried out for the sake of pure curiosity. The researcher is earning a living, burnishing a reputation, trying to prove a pet theory (or disprove a competing one), or all of the above” (p 268). After years of working and being educated in mental health. I have a ‘healthy skepticism’ about research. It is all to easy to see a research apriori assumptions by supported by tenuous evidence. The social ‘sciences’ seem to be most guilty of this. Knowledge is spread by contagion of charismatic academics with the birth order effect ‘research’ being an example. I still come across academics that begin talking about birth order effects.
Even though she has only written two books late in life she is a massive influence about how I think about parenting and being in this world. I love her calm writing style in which she will give the best argument for a theory, and then slowly pick it a part. I can understand that she is not more well known, because she roast a lot of our most sacred idol around personality and parenting, acknowledging we do not know as much as the experts make out. My take away point is. Relax, enjoy the ride. You are going to have to work hard to muck this up, just be good enough and have fun with it.
Rich-Harris provides a three pronged theory of the formation personality around the interaction between the relationship, socialization, and status systems. She hoped that others would be interested enough in her work find evidence of her theory as “Someone who thinks up a new theory is the last person who should be trusted with the job of testing it” (p 269). She inconveniently she died before anyone could do any work to prove or disprove for her theory. I found her theory plausable.
Rich-Harris also states “One of my goals in writing this book was to give you a healthy skepticism in regard to research. Researchers are human; they make mistakes; they have their own hopes and needs, their own beliefs. Doing research is a lot of work and is seldom carried out for the sake of pure curiosity. The researcher is earning a living, burnishing a reputation, trying to prove a pet theory (or disprove a competing one), or all of the above” (p 268). After years of working and being educated in mental health. I have a ‘healthy skepticism’ about research. It is all to easy to see a research apriori assumptions by supported by tenuous evidence. The social ‘sciences’ seem to be most guilty of this. Knowledge is spread by contagion of charismatic academics with the birth order effect ‘research’ being an example. I still come across academics that begin talking about birth order effects.
Even though she has only written two books late in life she is a massive influence about how I think about parenting and being in this world. I love her calm writing style in which she will give the best argument for a theory, and then slowly pick it a part. I can understand that she is not more well known, because she roast a lot of our most sacred idol around personality and parenting, acknowledging we do not know as much as the experts make out. My take away point is. Relax, enjoy the ride. You are going to have to work hard to muck this up, just be good enough and have fun with it.
October 4, 2021
Reflecting Judith Harris' own liminal position with respect to academic psychology, this book reads somewhere between academic and a pop science. There's a good chunk of straightforward scientific argumentation drawing on a gamut of sources, but it's all presented straightforwardly, with a clear, folksy voice. Harris' topic in this and her previous book is a child's development of personality.
In the popular Western understanding, a person's trait owe to a peculiar combination of nature and nurture: how they were born and how they were brought up. Harris wants us to recognize nurture, i.e. parenting, as only one part (and, as it turns out, a relatively unimportant part) of a child's development. In particular, Harris thinks both contemporary psychology and popular understanding overestimate the role of parenting's contribution to a child's personality at the expense of underestimating the role of peers.
In this work, Harris advances a theory of child development centered around peer interactions. In particular, she understands this development as the result of the interplay of three mental modules. These are the relationship system (our capacity for distinguishing one another and forming unique and motivating relationships with one another, friendships, enmities, etc.), the socialization system (our capacity to understand our social world in terms of social groups, my family, my tribe, my city, coupled with a desire to fit in with a social group) and the status system (our capacity to rank social groups, who's top dog on the playground, coupled with a desire to rank highly in our own group). It is in the tussle of these motivations (coupled with a child's intrinsic pecularities, owing to their genetics and a host of environmental factors) that a child forms their personality in contact with their peers.
This theory is plausible enough, at least to a complete nonexpert like myself, and Harris' case is suggestive. Obviously, it would be beyond the ability of a lay person to assess the scientific case adequately. Even if the case ultimately falls apart, I think this book is still worth reading as along the way to her conclusion Harris conducts enlightening surveys of a range of topics. And it's a much more fun read than one might expect.
In the popular Western understanding, a person's trait owe to a peculiar combination of nature and nurture: how they were born and how they were brought up. Harris wants us to recognize nurture, i.e. parenting, as only one part (and, as it turns out, a relatively unimportant part) of a child's development. In particular, Harris thinks both contemporary psychology and popular understanding overestimate the role of parenting's contribution to a child's personality at the expense of underestimating the role of peers.
In this work, Harris advances a theory of child development centered around peer interactions. In particular, she understands this development as the result of the interplay of three mental modules. These are the relationship system (our capacity for distinguishing one another and forming unique and motivating relationships with one another, friendships, enmities, etc.), the socialization system (our capacity to understand our social world in terms of social groups, my family, my tribe, my city, coupled with a desire to fit in with a social group) and the status system (our capacity to rank social groups, who's top dog on the playground, coupled with a desire to rank highly in our own group). It is in the tussle of these motivations (coupled with a child's intrinsic pecularities, owing to their genetics and a host of environmental factors) that a child forms their personality in contact with their peers.
This theory is plausible enough, at least to a complete nonexpert like myself, and Harris' case is suggestive. Obviously, it would be beyond the ability of a lay person to assess the scientific case adequately. Even if the case ultimately falls apart, I think this book is still worth reading as along the way to her conclusion Harris conducts enlightening surveys of a range of topics. And it's a much more fun read than one might expect.
June 27, 2019
The premise of this book is brilliant, instead of examining how similar identical twins are she turns things around and attempts to explain why two people with identical genes and almost identical environments are so different. Her investigation is thorough; she cites dozens of fascinating studies and picks apart as many bad ones.
Following her logic is occasionally challenging but for the most part the book is accessible. My biggest gripes were with her style, she occasionally came across quite up her own ass and I also got annoyed every time she started comparing her investigation mystery novels... I hate Sue Grafton. I was also not terribly satisfied with her conclusion, she lays out an interesting framework of mental modules but once she ties it back in to why identical twins are different it just seemed to amount to developmental noise amplified through these modules which seems plausible but a little vague and bit trite.
Still a worthwhile read for any parent as it helps reframe the way we think about raising children.
Following her logic is occasionally challenging but for the most part the book is accessible. My biggest gripes were with her style, she occasionally came across quite up her own ass and I also got annoyed every time she started comparing her investigation mystery novels... I hate Sue Grafton. I was also not terribly satisfied with her conclusion, she lays out an interesting framework of mental modules but once she ties it back in to why identical twins are different it just seemed to amount to developmental noise amplified through these modules which seems plausible but a little vague and bit trite.
Still a worthwhile read for any parent as it helps reframe the way we think about raising children.
October 31, 2021
A great book that helps readers conceptualise what shapes personalities.
Genetic - ~50% of your personality is pre-defined by your genes
Home Nurturing - minimal to no impact to a child's personality development. Might only affect the way children behave at home
The 3 systems that might account for the remaining personality differences
- Relationship System (How to build relationship/interact with one individual to another)
- Socialisation System (How to blend into communities, i.e. by finding and imitating a prototype)
- Status System (How to define your role in the socialisation circle, i.e. how to make you stand out from the rest as the "funny one" "Strongest one" "Smartest one" etc.
Genetic - ~50% of your personality is pre-defined by your genes
Home Nurturing - minimal to no impact to a child's personality development. Might only affect the way children behave at home
The 3 systems that might account for the remaining personality differences
- Relationship System (How to build relationship/interact with one individual to another)
- Socialisation System (How to blend into communities, i.e. by finding and imitating a prototype)
- Status System (How to define your role in the socialisation circle, i.e. how to make you stand out from the rest as the "funny one" "Strongest one" "Smartest one" etc.
This entire review has been hidden because of spoilers.
September 18, 2015
Subtitle: Human Nature and Human Individuality.
Once upon a time, a mother and housewife name Judith Rich Harris, with a business on the side writing psychology textbooks, lost her faith. Which is to say, she turned against the prevailing school of thought of mainstream psychology at the time, which believed that early parental behavior exerted profound influences over a child's behavior and personality, and would influence their development throughout the rest of their lives. She wrote a book, 'The Nurture Assumption', which said essentially that children have their own disposition, their own personality, and there are some fairly stringent limits on what a parent can do to impact that. She published the book, it was reasonably successful, and then all hell broke loose.
Psychology, as a field, has a tradition going back at least to Freud of saying that our early childhood experiences are key to understanding our adult abilities (and neuroses). As a field (which is to say with some individuals who disagree) psychology likes to tell parents that if they perform their role well their kids will be mentally healthy, but if they screw up (in any of countless ways) their kids will be mentally scarred for life. Harris said, in effect, that there is such a thing as good enough parenting, and even if you do everything right as a parent it's still hard to predict how they will turn out. Psychology did not like this, and Harris was pilloried for it.
She came back with a second book. It is not exactly a peace offering.
It should be pointed out that not all of the big names in psychology condemned Harris. Evolutionary psychologists such as Steven Pinker have come to her defense. But Harris clearly delights in her role as heretic, as seen from the viewpoint of Freud or Skinner, and she take multiple opportunities to relate tales of heated exchanges between herself and her detractors.
The starting point for her current book is the phenomenon of conjoined (also sometimes called Siamese) twins. They are genetically identical, and obviously have had the same environment, or at least as close as parents can possibly arrange for. Why do they have distinctly different personalities? If the difference in "environment" between conjoined twins is large enough to impact personality, that is more or less the same as saying that personality and ability can be impacted by environmental differences too tiny for parents ever to keep track of, and it might as well be random.
Which would be one fair answer. Harris thinks we can do better than "it's random", though, and she sets out to determine (in light of every study she can find on twins, siblings, half-siblings, and step-siblings) what is going on in human development, besides genetics. The current rule of thumb (until recently controversial) is that something just under half of the variation in personality and ability between people, is due to genetics.
The first half of the book, Harris disposes of five "red herrings", as she calls them. This involves convincing the reader of such uncomfortable truths as the fact that parental control of the environment inside the home doesn't affect much other than how the child behaves inside the home. People wish to believe (whether they identify with the role of parent or grown-up child looking back) that how parents run their home shapes how the child raised there turns out. Aside from pathological cases of horrific abuse, there is little evidence that this is so, and much that it is not so.
The second half of the book involves Harris putting forth her model (hint: it's grounded in evolutionary psychology and game theory). I am not prepared to pronounce judgment on it at this point; it sounds plausible, and testable, but I'm not in a position to test it myself. Hopefully, the gauntlet she has thrown down to the psychology community will be picked up by a researcher or three (Harris has health issues which prevent her from doing the research herself, and in any event no one should be trusted to test their own publicly stated hypothesis).
So, how does it all read?
Despite the frequent references to research performed by others, Harris' personality definitely shines through. When a few hundred pages into the book, she says "as a child I flunked socialization", we are not surprised. If you like to read of the slaughtering of the sacred cows of the ivory tower (<-mixed metaphor), Harris is likely to please.
One quibble: she likes to quote from her favorite works of fiction (Arthur Conan Doyle, Sue Grafton, Josephine Tey), in a way which I'm sure she thinks is meant to illustrate but which I found distracting. Perhaps for the reader who is less tolerant of study citation after study citation, the occasional literature or pop culture reference is more welcome. I consider it a minor blemish.
Overall, "No Two Alike" is a thought-provoking and highly readable book. It's packed with references, with enough details in the main text to back up what she is saying is or is not so. She is taking on some fairly deep-rooted beliefs, things we WANT to be true, and showing us that they are not all true, and this is something I always respect (whether I agree in the end or not). Her work straddles the line between popular science and original work (because her models of human development yield testable predictions), in more than one way, because she is in many cases drawing psychology's attention to the consequences of its own researchers' work. It will take time (and further research) to see if Harris is a visionary or an entertaining crank, but in either case, her book is worth reading, and thinking about.
Once upon a time, a mother and housewife name Judith Rich Harris, with a business on the side writing psychology textbooks, lost her faith. Which is to say, she turned against the prevailing school of thought of mainstream psychology at the time, which believed that early parental behavior exerted profound influences over a child's behavior and personality, and would influence their development throughout the rest of their lives. She wrote a book, 'The Nurture Assumption', which said essentially that children have their own disposition, their own personality, and there are some fairly stringent limits on what a parent can do to impact that. She published the book, it was reasonably successful, and then all hell broke loose.
Psychology, as a field, has a tradition going back at least to Freud of saying that our early childhood experiences are key to understanding our adult abilities (and neuroses). As a field (which is to say with some individuals who disagree) psychology likes to tell parents that if they perform their role well their kids will be mentally healthy, but if they screw up (in any of countless ways) their kids will be mentally scarred for life. Harris said, in effect, that there is such a thing as good enough parenting, and even if you do everything right as a parent it's still hard to predict how they will turn out. Psychology did not like this, and Harris was pilloried for it.
She came back with a second book. It is not exactly a peace offering.
It should be pointed out that not all of the big names in psychology condemned Harris. Evolutionary psychologists such as Steven Pinker have come to her defense. But Harris clearly delights in her role as heretic, as seen from the viewpoint of Freud or Skinner, and she take multiple opportunities to relate tales of heated exchanges between herself and her detractors.
The starting point for her current book is the phenomenon of conjoined (also sometimes called Siamese) twins. They are genetically identical, and obviously have had the same environment, or at least as close as parents can possibly arrange for. Why do they have distinctly different personalities? If the difference in "environment" between conjoined twins is large enough to impact personality, that is more or less the same as saying that personality and ability can be impacted by environmental differences too tiny for parents ever to keep track of, and it might as well be random.
Which would be one fair answer. Harris thinks we can do better than "it's random", though, and she sets out to determine (in light of every study she can find on twins, siblings, half-siblings, and step-siblings) what is going on in human development, besides genetics. The current rule of thumb (until recently controversial) is that something just under half of the variation in personality and ability between people, is due to genetics.
The first half of the book, Harris disposes of five "red herrings", as she calls them. This involves convincing the reader of such uncomfortable truths as the fact that parental control of the environment inside the home doesn't affect much other than how the child behaves inside the home. People wish to believe (whether they identify with the role of parent or grown-up child looking back) that how parents run their home shapes how the child raised there turns out. Aside from pathological cases of horrific abuse, there is little evidence that this is so, and much that it is not so.
The second half of the book involves Harris putting forth her model (hint: it's grounded in evolutionary psychology and game theory). I am not prepared to pronounce judgment on it at this point; it sounds plausible, and testable, but I'm not in a position to test it myself. Hopefully, the gauntlet she has thrown down to the psychology community will be picked up by a researcher or three (Harris has health issues which prevent her from doing the research herself, and in any event no one should be trusted to test their own publicly stated hypothesis).
So, how does it all read?
Despite the frequent references to research performed by others, Harris' personality definitely shines through. When a few hundred pages into the book, she says "as a child I flunked socialization", we are not surprised. If you like to read of the slaughtering of the sacred cows of the ivory tower (<-mixed metaphor), Harris is likely to please.
One quibble: she likes to quote from her favorite works of fiction (Arthur Conan Doyle, Sue Grafton, Josephine Tey), in a way which I'm sure she thinks is meant to illustrate but which I found distracting. Perhaps for the reader who is less tolerant of study citation after study citation, the occasional literature or pop culture reference is more welcome. I consider it a minor blemish.
Overall, "No Two Alike" is a thought-provoking and highly readable book. It's packed with references, with enough details in the main text to back up what she is saying is or is not so. She is taking on some fairly deep-rooted beliefs, things we WANT to be true, and showing us that they are not all true, and this is something I always respect (whether I agree in the end or not). Her work straddles the line between popular science and original work (because her models of human development yield testable predictions), in more than one way, because she is in many cases drawing psychology's attention to the consequences of its own researchers' work. It will take time (and further research) to see if Harris is a visionary or an entertaining crank, but in either case, her book is worth reading, and thinking about.
September 18, 2022
one of the absolute worst books I have read in a long time...
a book should be build upon ideas and exploring them and explaining them, not 150 pages of denying other scientists opinions.. then the next 150 pages talking about sherlock holmes etc?... why to add that?
this book could have been written in 5 pages, terrible....
a book should be build upon ideas and exploring them and explaining them, not 150 pages of denying other scientists opinions.. then the next 150 pages talking about sherlock holmes etc?... why to add that?
this book could have been written in 5 pages, terrible....
October 23, 2018
Thought provoking
An interesting perspective on why humans differ in personality. In my opinion (and Charlie Munger’s I’m sure) what’s more interesting is the way she challenges conventional wisdom and applies logic to the data that has already been compiled.
An interesting perspective on why humans differ in personality. In my opinion (and Charlie Munger’s I’m sure) what’s more interesting is the way she challenges conventional wisdom and applies logic to the data that has already been compiled.
May 4, 2023
Judith harris es oficialmente la autora más insoportable que leí y el objeto más pesado del universo por el amor de DIOS cómo puede alguien llegar a escribir de manera tan condescendiente?? prefiero continuar sin saberlo
June 5, 2022
My book 6/1/2022
March 16, 2017
I found the book to be a bit defensive and self-indulgent. While I found her perspective interesting, I was often a bit distracted by her efforts to defend herself against and even tear down her contemporaries. Disproving their theories is one thing, but this seemed much more personal. Overall interesting data that could have been presented better!
August 4, 2013
This is the first book of Harris' that I've read. (Although I've read so many books drawing on the ideas in the "Nurture Assumption" that I doubt if I ever get round to reading it, I'll find anything new there. Much in the vein of "Seinfeld is Unfunny" TVTropes).
Harris proposes an interesting way to think about personality - as something formed through the interaction of three systems - the relationship, socialization and the status systems. A large chunk of the book is spent in eliminating the various 'suspects' to find the one true culprit who will account for all the non-genetic variation in personality. While the debunkings and the elimination of the suspects are informative, one wishes she would ease up on her replies to various critics and academics who do not take her seriously for lacking a PhD. (While trying to mentally organize what the book was about, to write this review barely a month after reading it, my brain keeps helpfully bringing up - "oh and some academics who do a lot of shoddy work don't take her seriously, and this annoys her").
At the end of it though, despite her assertions at the beginning that the cause of the unexplained variations is not 'noise', it turns out it is noise after all, or rather noise once-removed. Two identical twins, both having the exact same genetic material and nearly the same family environment and peer group, differ from each other because they have different entries in the mental lexicon of those they interact with (the other nodes in their relationship system). This in turn influences their self-perception and their personalities begin to diverge. But where would these different entries arise in the first place? Actually, noise did it.
Harris proposes an interesting way to think about personality - as something formed through the interaction of three systems - the relationship, socialization and the status systems. A large chunk of the book is spent in eliminating the various 'suspects' to find the one true culprit who will account for all the non-genetic variation in personality. While the debunkings and the elimination of the suspects are informative, one wishes she would ease up on her replies to various critics and academics who do not take her seriously for lacking a PhD. (While trying to mentally organize what the book was about, to write this review barely a month after reading it, my brain keeps helpfully bringing up - "oh and some academics who do a lot of shoddy work don't take her seriously, and this annoys her").
At the end of it though, despite her assertions at the beginning that the cause of the unexplained variations is not 'noise', it turns out it is noise after all, or rather noise once-removed. Two identical twins, both having the exact same genetic material and nearly the same family environment and peer group, differ from each other because they have different entries in the mental lexicon of those they interact with (the other nodes in their relationship system). This in turn influences their self-perception and their personalities begin to diverge. But where would these different entries arise in the first place? Actually, noise did it.
March 28, 2013
Judith Rich Harris "No Two Alike" provided for me the second half of understanding becoming a person, also referred to as building a self. This work, written during her life-threatening illness, uses the detective story model to understand how personality is build to temperament: the first part (chapter 7! is basic socialization: a supportive mothering! (Check Blum, Deborah. Love at Goon Park: Harry Harlow and the Science of Affection. Perseus Publishing, 2002. ISBN 0-7382-0278-9)
In chapter 8, she explores "the socialization system", becoming involved in a social community in which people become involved in an social environment which continues their "formation": "develops their values" is how I see it. In the 9th chapter, she focuses on their progression in the community which is the home of their adult activity and achievement.
With this abstraction, I begin to understand the notion of personality being developed and getting its expression in a career. Teaching? Politics? Police Work? Financial Development? Technological Development? Scientific Inquiry?
I referred to Deborah Blum's biography of Harry Harlow, and the development which led him to his fundamental of re-focussing psychology from behaviorism. I was impressed with the book by Kandel, E. R. (2007), In Search of Memory: The Emergence of a New Science of Mind, New York: W. W. Norton & Company, ISBN 978-0-393-32937-7. He explains the education, early career, and work which led to getting the Nobel Prize, and also tells of the biological processes by which the brain forms a memory of events.
In chapter 8, she explores "the socialization system", becoming involved in a social community in which people become involved in an social environment which continues their "formation": "develops their values" is how I see it. In the 9th chapter, she focuses on their progression in the community which is the home of their adult activity and achievement.
With this abstraction, I begin to understand the notion of personality being developed and getting its expression in a career. Teaching? Politics? Police Work? Financial Development? Technological Development? Scientific Inquiry?
I referred to Deborah Blum's biography of Harry Harlow, and the development which led him to his fundamental of re-focussing psychology from behaviorism. I was impressed with the book by Kandel, E. R. (2007), In Search of Memory: The Emergence of a New Science of Mind, New York: W. W. Norton & Company, ISBN 978-0-393-32937-7. He explains the education, early career, and work which led to getting the Nobel Prize, and also tells of the biological processes by which the brain forms a memory of events.
August 23, 2008
I don't think that Judith Rich Harris is the final authority on her topic, but she does an impressive job of synthesizing research on the development of personality. She also piercingly explains specific statistical techniques and research methods (and points out instances of others' sloppy work!). Harris builds a compelling case that individuals' personality differentiation results from our pursuit of status through whichever niches fit us and are available. She contends that our status-seeking behavior is supported by a) our ability and tendency to differentiate between other persons even if they are very similar, and to collect and store information about them in our memory, and b) our ability and tendency to soak up social norms (to become socialized). In Harris's model, whereas the process of socialization makes individuals more similar, simultaneously we distinguish ourselves through social competition (status seeking).
Drawing on her previous work in The Nurture Assumption, Harris holds that individuals tend to become socialized much more by their peer group than by their parents. Thus, if parents want their kids to share their values, they should arrange for their kids to be in proximity with other children of whom the parents approve. Parental modeling may not be nearly enough to shape a kid's personality.
Harris also points out that much of personality (perhaps 50%) is genetic. Her task in this book is to account for as much as possible of the remaining variance.
Drawing on her previous work in The Nurture Assumption, Harris holds that individuals tend to become socialized much more by their peer group than by their parents. Thus, if parents want their kids to share their values, they should arrange for their kids to be in proximity with other children of whom the parents approve. Parental modeling may not be nearly enough to shape a kid's personality.
Harris also points out that much of personality (perhaps 50%) is genetic. Her task in this book is to account for as much as possible of the remaining variance.
February 9, 2008
The first 2/3 of the book is great; Harris rips into current theories explaining variance in personality, including birth order (and other environmental differences) and gene-environment correlations. The last 1/3 of the book, in which Harris attempts to construct her own theory to determine the cause of the currently-unexplained variance in personality is not entirely convincing.
I especially liked the section in which Harris discusses the problem of the generalization assumption held by nurturists (i.e., that people generalize strategies from one context to another). Her debunking is thorough and convincing: interactions with parents don't lead to generalized strategies of actions in other contexts - such as strategies of how to act among peers.
A very interesting read for anyone interested in human nature, personality, and genetics.
I especially liked the section in which Harris discusses the problem of the generalization assumption held by nurturists (i.e., that people generalize strategies from one context to another). Her debunking is thorough and convincing: interactions with parents don't lead to generalized strategies of actions in other contexts - such as strategies of how to act among peers.
A very interesting read for anyone interested in human nature, personality, and genetics.
September 4, 2014
An outsider challenges the orthodoxy on child development is how I read this book. Humans are different 45% due to genetics and 55% due to unknown causes. But no known input of the form "Do x to your child and you'll be more likely to get y." is valid for social traits or personality. An interesting point is that if a child is bad today, that's deemed bad parenting where 100 years ago it might have just been seen as the parents being unlucky for "the child they got."
So parents should avoid hubris about their ability to "shape" a child. It's murky at best; nearly non-existent at worst.
As a book, the occasional journeys into personal anecdote or quotation of fiction for insight works in the small quantities she allows herself.
My 18th ever 5-star rating for a book. My average rating is 3.02 as of today.
So parents should avoid hubris about their ability to "shape" a child. It's murky at best; nearly non-existent at worst.
As a book, the occasional journeys into personal anecdote or quotation of fiction for insight works in the small quantities she allows herself.
My 18th ever 5-star rating for a book. My average rating is 3.02 as of today.
February 23, 2012
It took me a long time to read this book, but it was interesting. More investigation by the author of the Nurture Assumption, this time why people turn out differently, including identical twins. People undergo different paths of development - socialization which makes us more the same and status seeking, which makes us different. According to Harris, there is also a relationship system - providing us with allies in life.
Harris has some ideas on how research in these areas has been misleading. I think the book does open some questions and shows us that psychology has a long way to go in understanding human development.
Harris has some ideas on how research in these areas has been misleading. I think the book does open some questions and shows us that psychology has a long way to go in understanding human development.
May 18, 2013
This is the second book by Harris that has shifted my world perspective.
Question: Why are people different, even if they have the same genes (identical twins) and environment?
It's a way-complicated theory, but it goes something like this...
Answer: The relationships system and the status system.
Individuals need to differentiate between other people, so they find something a little "different" and categorize someone that way. i.e. "That twin is the friendly one." That other person picks up on how she is viewed by others and may live up to that classification or try to change it.
Question: Why are people different, even if they have the same genes (identical twins) and environment?
It's a way-complicated theory, but it goes something like this...
Answer: The relationships system and the status system.
Individuals need to differentiate between other people, so they find something a little "different" and categorize someone that way. i.e. "That twin is the friendly one." That other person picks up on how she is viewed by others and may live up to that classification or try to change it.
This entire review has been hidden because of spoilers.
April 28, 2016
Reading "No Two Alike" made me look at certain relationships, such as parent-child relationships, differently than before. I found some of the reading to be a little tedious, it seemed as if she wrote the book for two audiences; she included many studies, sources and detail for people in her field but also included some humor in it which made it a little more enjoyable for an audience such as myself. Am I convinced? Partly, I guess I would say I'm a little surprised too. In the end I say it definitely gives me plenty to think about.
July 13, 2007
Judith Rich Harris is a champion of the scientific method. I admire her for working so hard at her research in spite of her physical limitations. I think her formal descriptions of three main systems in our brains that are responsible for making us all so similar, unique, and competitive is pretty compelling. Her digressions are also pretty entertaining.
February 29, 2012
I found it very interesting, but did not like the style at all. Too much superiority, nastiness.
I am not sure I really agree to the whole of the hypothesis -- my gut is that the family is more important that Harris says -- but I did find her ideas challenging and refreshing. Definitely have made me question my own assumptions.
I am not sure I really agree to the whole of the hypothesis -- my gut is that the family is more important that Harris says -- but I did find her ideas challenging and refreshing. Definitely have made me question my own assumptions.
October 8, 2014
Harris elaborates her theory on how and why each person develops a unique personality (even identical twins). But first she pauses to consider, then demolish, rival theories. The pause takes up the first two-thirds of the book and makes for great reading. The theory itself seemed somewhat light on the details.
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