Innate: How the Wiring of Our Brains Shapes Who We Are

by Kevin J. Mitchell, Michael Page (Narrator)

A leading neuroscientist explains why your personal traits are more innate than you think What makes you the way you are--and what makes each of us different from everyone else? In Innate, leading neuroscientist and popular science blogger Kevin Mitchell traces human diversity and individual differences to their deepest level: in the wiring of our brains. Deftly guiding us through important new research, including his own groundbreaking work, he explains how variations in the way our brains develop before birth strongly influence our psychology and behavior throughout our lives, shaping our personality, intelligence, sexuality, and even the way we perceive the world. We all share a genetic program for making a human brain, and the program for making a brain like yours is specifically encoded in your DNA. But, as Mitchell explains, the way that program plays out is affected by random processes of development that manifest uniquely in each person, even identical twins. The key insight of Innate is that the combination of these developmental and genetic variations creates innate differences in how our brains are wired--differences that impact all aspects of our psychology--and this insight promises to transform the way we see the interplay of nature and nurture.

Genres: Science, Psychology, Neuroscience, Nonfiction, Biology, Brain, Audiobook

304 pages, Hardcover

Published October 16, 2018

About the author

Kevin J. Mitchell is associate professor at the Smurfit Institute of Genetics and the Institute of Neuroscience at Trinity College Dublin. He is a graduate of the Genetics Department, Trinity College Dublin and received his Ph.D. from the University of California at Berkeley.

Reviews

[Always Pouting · Rating 4 out of 5]

I always really enjoy these science books but then at the same time I feel like the material is too introductory for me and so like it's useful to read to reinforce my knowledge but what I really want to know more about is the research and the papers. At the same time though am I really going to go try to pirate these scientific papers one by one on my own time when I would just prefer the convenience of a book. Someone publish like a meta-analysis for everything neuroscience but in book format which also breaks down methodology and the statistical analysis. That's truly all I want from the world. But outside of that this was enjoyable and I felt like it really cemented a lot things I had thought about neurophysiology already. I think its also left me quite unsure about the ethics of all that information and what it means for how we relate to one another/how much responsibility we should put on others and all the other myriad of issues brought up. I mean Mitchell doesn't claim to have answers to those questions either so. I will definitely be going through his blog next though. Really curious about the details of how one determines how connections between the brain are made etc. Some of it was covered but yeah I'd always love to know more.

[Morgan Blackledge · Rating 5 out of 5]

After reading Kevin Mitchell’s Innate, the first reflection that comes to mind is....

Damn!

This mother f***er can write!!!

In point of fact.

He’s on FIRE 🔥

Despite the fact that he threw the entire contents of the proverbial ‘kitchen sink’ into this book.

It’s lucid and accessible.

The pace is LITERALLY nonstop.

Mitchell bombs you with well constructed argument after well constructed argument.

But somehow, you’re not shell shocked by the end.

BRILLIANT.

If you’re an educated reader, you may not walk away from Innate with a lot of “new” information.

But you’re all but guaranteed to have either a new more realistic outlook on human development, or at least have some of your old ideas challenged.

#FirmwareUpgrade

The basic premise of Innate is simple.

DNA encodes a genetic program for making human brains, and brains make us who we are (to an overwhelmingly large extent).

But the way that the genetic program ultimately plays out is far from deterministic in any simple sense.

It’s affected by obvious stuff like the environment, social milieu, and culture.

Yeah sure.

But a system as complex as a brain is also significantly effected by random processes, such that if you were to clone yourself 100 times, there will all but certainly be greatly different outcomes in important psychological traits, even if you controlled for all that other stuff (like environment, social milieu, and culture etc).

In other words, two identical twins 👯‍♂️ raised in the same or even completely different environments, will likely emerge with durable similarities (because DNA).

We all know this.

But... these same twins, also may emerge from identical environments with significant differences, purely by dint of stochastic (random) processes, occurring entirely in the frothy complexity of each individual brain 🧠.

And these differences may be quite significant.

One (genetically) identical twin may be gay, the other straight.

One identical twin may be schizophrenic, the other not.

All because of what essentially boils down to a roll of the dice.

Or rather, the roll of billions of tiny molecular dice, that are more like crazy complex little dungeons and dragons dice.

In other words, DNA makes people more or less likely to display certain traits (sometimes way way more or less likely), but dumb luck (probability) still plays a big role, even at the deepest level of our biology.

Other stuff that we commonly think of as having a durable effect, like parenting etc.

Well....

Not as big of a deal as you probably think.

It has a ginormous impact.

Yes.

But les durable than so called ‘innate’ shit.

This pokes a hole in a lot of the etiological claims of psychotherapy, and a lot of ‘change’ claims touted by the self help industry.

Yes you can change your life in important ways.

But if you quit doing the stuff that made the changes happen, like exercise, diet and meditation etc., you revert to a largely genetically determined baseline quickly.

So, yes you can change your ‘self’ but the change is constrained (i.e. WAY limited) and is dependent on effortful long term behavioral and environmental change.

In the end, Mitchell promotes a kind of radical self acceptance over endless self improvement strategies.

You can overcome stuff like anxiety, depression and addiction, absolutely.

And it’s worth it.

But some stuff, well...

Ya just can’t.

Cuz it’s innate.

So maybe it’s better to simply:

Accept the shit you can’t change. Change the shit you should (provided it’s worth the serious time and effort). And get your shit straight about which is which.

I LOVED this book.

[Camelia Rose · Rating 4 out of 5]

Innate presents a lot of interesting findings on how genetic and developmental forces make who we are. The author argues that the wiring of our brain is more innate than you and I would think. The "innate" here refers not only to our genetic makeup, but also the developmental influences, i.e. the actual realization of the genes, the randomness in fetal or early childhood development, which is a part of the "nature" not "nurture".

The author draws from many studies, especially twin studies (monozygotic twins vs dizygotic twins, monozygotic twins reared apart), on personality traits, sexual preferences, intelligence and mental disorders. I find it intriguing that one's environment does not have a long lasting effect on these innate characteristics (the author does not mean the behavioral outcome, but the underline trait, although I find it may be hard to separate an actual outcome from the underline trait in real life situations). For example, "...these findings suggest that many reported correlations between parental behavior and offspring traits do not reflect direct causal link as often inferred, but instead, reflect the effect of shared genes. If, for example, we find overprotective parents have anxious children, this could be because overprotective parenting causes children to be anxious, but evidence described is not consistent with such interpretation, as it should affect monozygotic and dizygotic twins, or adopted and biological offsprings equally. Instead, the general finding suggests parental overprotectiveness and child anxiety are more likely both manifestations of the same genetic effect, acting in both parents and offspring. Similarly growing up in a household with more books is correlated with higher IQ. Does this mean reading raises your IQ? Well, I am all for reading, but this correlation is likely that parents with higher IQ tend to have more books in the house and tend to have children with higher IQ." What is the implication of such findings?

On randomness in brain development: you can't bake the same cake twice. Your genome is a set of coded instruction, not a blueprint. Randomness plays a part in the development from genes to the actual functioning human brain. Your clone is different from you in many ways, even as a baby.

The author makes excellent argument on why we can't use IQ test results between different populations to infer the group difference in intelligence.

Chapter 9 is dedicated to the differences between sexes. Again, a lot of interesting arguments. The explanation of why homosexuality is innate (may or may not be genetic) is fascinating. It seems the differences of various personality traits between sexes do exist. Although each trait has a wild spectrum overlapping between two sexes, there seems also an overall brain profile, a combination of several traits that can tell if it is a male brain or a female brain. IQ wise, although there is no overall difference between sexes, the distribution curve of IQ in male and female population is different. Are women better at language than men? Yes, several studies result in consistent findings. Are men better at math than women? No, the findings in different studies are inconsistent. The author argues that it is unscientific if all such discussion is branded as "neuro-sexism", and it is the interpretation of these findings that may cause issues, not the findings themselves. I agree. However, because of the existing gender discrimination, scientists need to be extra mindful when publishing such findings, as the misinterpretation, intentional or unintentional, is bound to happen. I believe scientists have moral responsibility, perhaps more so than the average citizens.

Other interesting points: we are born prewired--genetically and developmentally, but not hardwired; the role of serotonin in brain development and functioning is truly complex and fascinating; our mind is a not a thing, but a process, the brain at work; when it comes to mental disorders, having one or several gene mutations often does not infer one will surely develop certain symptoms, but only the propensity, the higher likelihood of such misfortune; higher general intelligence may be the result of less load of harmful mutations.

The last chapter, chapter 11, implications, is the fine prints of the main arguments made in the book, to avoid misinterpretation by the general public. It includes the discussion of the new eugenics.

The author is dismissive to epigenetics. As a layperson, I am not qualified to argue with Prof. Mitchell, but I'd love to see more discussions on this topic. This is the fun of science, isn't it?

The author is not a fan of self-help books, which he thinks often exaggerate the role of neuroplasticity and make nonsensical claims. I find his view too narrow. Neuroplasticity in adults is achievable, so what's the harm of making it known to the public? Also, has he looked into mindfulness meditation?

[Nathan · Rating 2 out of 5]

There is a growing crisis in the fields of genetics and evolutionary psychology with mischaracterization and misinformation in their popular literature. There seems to be a reinforcing tradition of pushing the strength of biological reductionism beyond the actual scientific implications and actively erasing all research for other causal effects. Unfortunately, this book continues this tradition.

I've already had my Twitter exchange with Dr. Mitchell, and although there was some concession that some important mechanisms were missed it mostly ended up with that fallback that every geneticist says more as a platitude than a scientific assertion: well, overall it's an interplay of genetics and environment. And the overall weighting of the influences, which they've just asserted to be one very asymmetric way, they fall away from making quite such a definite assertion, but nothing comes of it. Their stronger assertion stays the position of record. There are no second editions to correct the record. And book by book it goes, misrepresentation and misinformation.

Despite the social media exchange, I think this review should still review in some detail the primary problems this book presents.

This is a book that looks to describe the innateness of neurological phenotype expression. For this book, innateness means more than just genetics, though that is the primary mechanism explored. It also means by innateness those other parts of expression outside our control, like the inherently stochastic dynamics of ontogeny and the processes in the environment also driven by innate expression.

And the book bends so much of the science dishonestly here for this goal. Let me go over the different processes with causal effects on the phenotypes and point to the problematic emphases, ommisions, and misstatements to give the fuller picture.

The genetic scale has a fair amount of description dedicated to it. You get the classic middle-school review of DNA, bases and their pairing, gene start/end markers, and an abridged description of transcription and translation. There isn't a lot of the detail about the transcription codons and their differential mutational neighborhoods, which would give some better awareness of the actual levels of robustness and mutation-sensitivity of the genome which gets played on a lot later. In fact, this book steers clear from numerical attributions of effect strength ecept in one telling (and misleading) exception: heritability.

The book gives a strange description of the measurement of heritability. It goes into the nature of correlations (giving a brief tour of Galton's wider contributions) and describes the genetic influence in monozygotic and dizygotic twins. But here it fails completely to describe the full diversity of effects that cannot be removed from the relative correlational adjustments which make up the (broad-sense) heritability function. At no point does he describe how all cultural biases against one inherited trait that act out to affect the expression of other phenotypes will measure as heritability in that latter phenotype despite having nothing to do with a mechanism of genetic expression of the latter phenotype. These kinds of examples that show where heritability may hide cultural controllability are never discussed around heritability.

The closest the book comes to such a conversation is this strange aside where the possibility that people may have innate traits (due to their genes) that may make them more likely to be abused, and that may reinforce traits that make them abusers when they grow up. This strange aside insists it is not intending to blame the victims of abuse (even though it really kind of is) and is completely concerned in it's description in pointing out how the development of one uncontrollable trait may influence other traits in innate ways through the environment. At no point is it pointed out that the environment can be controlled, or any of the research on intervention. It certainly does not discuss example like a child with minority racial traits having expression of some phenotype affected by social bigotries and what kinds of traits the research has shown such biases in.

The description of expression mentions in passing some pieces of expression, but doesn't really pull it together and connect it with a bogeyman word attacked throughout the book: epigenetics. We know that methylation can affect gene expression in a way to hide perfectly healthy variants from transcription. We know how the geometry of protein layout in the germ cells can affect the geometry of ontogeny. We know of metabolic millieu that can be inherited outside of the genes themselves. And we know that these kinds of things may be affected by environment through slow information-encoding processes that may have occurred in the parental lifetime and earlier.

In other words, we now have decades of research showing there are a variety of intermediate processes that can change the outcome of genetic causal paths, and that some of these are environmentally affected (though slowly, and typically most importantly through the parents before ontogeny).

So it is very telling that he makes fun of epigenetics. Apparently there are some who are selling epigenetics as some kind of self help and self-control panacaea, and he has taken it as an important point of this book to combat that belief. I personally have not read those kinds of books, and my exposure to epigenetics started in college with the Jablonka / Lamb book and has explored the journal literature from there. But he describes none of the actual research, and instead just makes some very demeaning comments about epigenetics as if it were simply his caricature he presents. This is the first major deception of the book.

When he describes the stochastic nature of development, he again focuses on the lack of control - this time in the source of randomness. An honest description that understood epigenetics would have pointed out the possible influence of epigenetic factors and maternal environment controls. During development, many chemicals are supplied the embryo from the mother, including nutritional (sugars, amino acids, fats, metabolic co-factors), as well as other chemicals affecting metabolic process (alkaloids, terpenoids, etc. from normal consumption or medications from intentionally directed consumption/injection/etc.).

He just repeatedly skips these environmental controls.

So when he gets to neuroplasticity - well that's just another caricature. Again, he gives none of the decades of research on how we are able to train different components of the nervous system. Again, he laughs at something he read in some really poorly researched self-help book somewhere and pretends that the professional study of neuroplasticity looks like it. So he talks about the possibility of developmental tendencies and their genetic influences, but does not go into the mechanisms of neuroplasticity and the research into their various scopes over different components.

In these ways, the book tilts it's uninformed readers into believing a biological reductionism that is not justified by the science.

It's not like this is an either-or proposition either. We have lots of very cool and important research on causal paths of genetic expression. And we have lots of cool information on epigenetics and it's realm of controls. And we have information on maternal controls on developmental environment. And we have tons of research on neuroplasticity and it's domains. And there is a lot still unknown. Telling that story, though, would not be done in a book titled "Innate".

I honestly don't know what to do about the dishonesty in these fields. I really don;t know why there is this concerted effort to make these misstatements and no concern shown about the misstatements. I pointed to Dr. Mitchell his misleading description of heritability and how every time he used a heritability number like 0.6 or 0.8, he would directly state (not even just imply) that that showed the variability of the trait was controlled 60 or 80% by genes (and let's not go into effects whose expression is not additive but multiplicative [likely most of them], which is a huge mistake in this view on a much more foundational level) - when I pointed out this - he didn't feel the need to change that message. Instead, he had some other revisions he would make but generally wasn't concerned about outright misstatements.

The same with Stuart Ritchie, who has never once responded to my pointing out the same heritability errors in his book.

The same with Richard Haier, whose journal Intelligence publishes papers all the time with the same misstaken view of heritability.

There is a lie that an entire field does not want to admit. That is not science. Something is making them _want_ to misrepresent. This is intentional. That is scary.

[Aroosha Dehghan · Rating 2 out of 5]

کتاب خوبیه برای سر درآوردن از کارکرد مغز و اثر عوامل گوناگون بر شخصیت انسان.
مثل بسیاری از کتاب‌های مشابهش، این کتاب هم قرار نیست زندگیتون رو متحول کنه یا کمک کنه تغییری در زندگی ایجاد کنید.
صرفا یک سری اطلاعات بهتون میده از چیزهایی که دست خودتون نیست ولی خیلی رو زندگیتون اثر داره.
اینجور کتاب‌ها به‌شدت به درد کاهش خارش غدد کنجکاوی میخورن😅

[Stetson · Rating 5 out of 5]

Innate is an excellent primer on how the genome influences neurological and psychological traits in humans. Mitchell, a professor of neurogenetics and blogger at "Wiring The Brain," illustrates how variation in genes has been shown to contribute to variation in intelligence, personality, and the whole range of human social and psychological phenotypes.

There are many books on this subject, such as Blueprint by Robert Plomin or The Genetic Lottery by Kathryn Paige Harden. However, Mitchell's contribution is his focus on the contribution of stochastic developmental processes to phenotypic variation. Mitchell argues that much of the "non-shared environment" captured by ACE twin model studies is likely to be the random noise of developmental processes along with some degree of measurement error.

Beyond the careful and clear explanation of the science of psychiatric genetics, Mitchell explores a lot of interesting human neurobiology and biopsychology that is often omitted from popular science tracts. For instance, he writes engagingly about synthesia.

I strongly recommend this book.

[Liam Tjia · Rating 5 out of 5]

Excellent book. Everyone working in early child development should read this, including developmental paediatricians like me.

The author advances answers and explanations for many of the fundamental questions which vex clinicians such as myself. The difference from most such fare is that this guy knows what he’s talking about. He really really knows his stuff.

Two aspects make this book stand out. The author demonstrates the infallible sign of true mastery of the subject of discussion - the ability to use plain English, and explanations by analogy, to convey complex concepts to also-ran readers like me.

That feat is allowed in part by the author’s command of related contemporary psychology, and philosophy. The insight on show, in those areas, is deeper than that displayed by many current loudmouth professional psychologists and philosophers.

The most important concept expounded, the most important fact for any clinician reader to grasp, is that of the many-to-one and one-to-many relation between genetic variations on the one hand, and clinically defined entities such as autism and schizophrenia, on the other. Autism can be caused by many different genetic variations; because it is not really one disease/disorder. Whereas one genetic variation which causes autism in one individual will cause a different ‘condition’, or nothing at all, in another individual.

But there’s heaps of other important, interesting stuff too.

Complaints? Well, I could point out that the book does not contain any sophisticated examination of the construct of ‘ADHD’, only passing mentions. This is almost certainly because the author has spent no time in his academic life, examining the entity himself. This in turn indicates that the author isn’t stupid, since examination of the quasi-entity currently called ADHD is obviously a dead end which no amount of attempted sciencing will add to. So, fair enough.

Also, I listened to the audiobook. I understand the choice of a fairly posh sounding English narrator, who did an excellent job. Americans can’t understand most Strine (unadulterated Australian accent and vernacular); only an enlightened minority would make sense of Full Irish Narration.

But still it seems a shame - key observations, such as the following contained in Chapter 9, would have sounded even more compelling if uttered by the likes of Dylan Moran: “Men also have thicker skulls, especially in front, which may reflect the fact that we like to punch each other in the face a lot.”

I give this excellent book 5 STARS OUT OF FIVE.

[Ginger Griffin · Rating 4 out of 5]

"Innate" is not synonymous with "genetic," as this book makes clear. Genes just code for the production of molecules (especially proteins), which then go to work building a body that works (or not). Along the way, a lot can happen -- especially when constructing something as complicated as a human brain. The brain has to wire itself as it develops, with many opportunities for randomness to affect the outcome. That means even monozygotic twins don't have identical brain architecture at birth.

So maybe you were planning to have yourself cloned? Don't bother. The result won't be another you. It will just be someone else with your genes. :-)

[Adrian Vestøl · Rating 5 out of 5]

Excellent primer for students of psychology (a student myself). It nicely sums up the essential concepts and the basic findings from developmental research. I judge it also easily accessible to the interested layperson.

The book adresses common misconceptions about the heritability of psychological traits, such as intelligence and personality. Genetic determinism is debunked in plain terms. How is it that identical twins most likely are extremely similar, but still in some cases might end up quite different? An important insight is that the role of environmental influences on development is unsystematic and random, contrary to commonly assumed. The book does an excellent job in unweaving the notorious concept of the heritability quotient.

An engaging read!

[Steve · Rating 5 out of 5]

A really fine book explaining how genetics affect our brains and minds. There are certain traits that are very strongly genetically associated, but in identical twins, with 100% identical DNA, if one twin has a trait the other twin only has 50% chance of having the same trait. How can that be?This book explains! A lot of who we are is “innate” in the sense that we are born that way, but our DNA has not precisely determined what we are, it has only prepared a situation where there are certain odds that we will be one way or the other. Well written and clear. I love it when a real scientist writes as well as a good science journalist!

[Adrian Crawley · Rating 5 out of 5]

Highly informative, and beautifully succinct resume of today's study of genetics.

The author manages to explain and teach the basics of genetics, neural pathways of the brain, the importance of mono-zygotic twin studies and much more.

I thoroughly enjoyed this book and learnt a lot.

[Tiago F · Rating 5 out of 5]

I wanted to get a deeper dive into genetics, but I didn't want to deal with genetics on a level that was too abstract. And given that I'm very keen on psychology, the genetics of psychological traits tend to interest me the most. So when I saw this book it looked like the perfect opportunity. The book is written by Kevin Mitchell, a very successful neuroscientist, and it explores what causes human diversity and individual differences. How genetic processes end up writing our brains differently, and how that ends up as different traits such as a personality, intelligence, sexuality, and so forth.

The broad point is that psychological and behavioral traits are heavily genetic. Depending on the trait, it can anywhere from 30% to 80%. This largely comes from studies dealing with twins (monozygotic twins vs dizygotic twins and monozygotic twins reared apart). The author doesn't spend too much time on this point, rightfully so. Despite controversial, it is a rather basic and accepted fact, and the book is focused on exploring why this is the case rather than arguing it to death as some have done.

The first part of the book was a very general introduction. Not only to genetics but because we are dealing with how the brain is wired, the brain itself. This alone is well worth the book, and it was a fantastic introduction to cognitive and neuroscience. In the second part, it goes into more specific areas of innate differences and their mechanisms.

The book is somewhat similar to Pinker's Blank Slate, but I liked this one better. It much heavier on the science, and it doesn't go so much on philosophy or politics. I hate when these topics are full of apologetics and endless cautionary statements. I understand why they are required, but I feel like they detract from the science which should be the main point. I found the author balances this perfectly. It only dives into politics and controversies when absolutely required, and keeps it very succinct and brief. The rest is science.

Something else that I liked is that the book had a wide range of topics, some politically controversial (like IQ or sex differences), and some very benign (like personality traits). But they were dealt, for the most part, the same. I think they should. It wasn't trying to avoid controversy by skipping hot topics, but likewise, it wasn't focusing on them to make the book controversial or aggressive.

Something that really stuck with me was how much randomness there is for genetic mutations. There is often a debate between nature and nurture. That is often a false dichotomy, but beyond that, it is missing an important variable entirely: chance. When studies often find a high contribution from genetics, it seems to assume that left-over is the environment. But often it is not (because that's measured with the shared environment of twins). Some of the variations is completely random from the neurodevelopmental process of the brain. Random fluctuations in cellular components are unavoidable noise that accumulates and ends up affecting how the brain is wired. Meaning that a trait can be only partly genetic but still entirely innate with little influence from the environment.

I really liked the author's emphasis on how genetics also shape the environment, making the dichotomy even more problematic. If one is musically talented, they are more likely to pursue musical training. The training isn't genetic, it is part of the environment. Yet, that environment was chosen based on a genetic influence. Viewing as a purely environmental factor is misleading. Another example given that I liked is how a child with autism may have less interest in people's eyes. This will lead to missing social cues that will shape the development of language and communication. Where do these social deficits come from? They weren't purely genetic, but they certainly can't be attributed to the environment alone either. Another topic that covered often was that genetics isn't simply how you're born. It is a developmental process which includes maturation. Much like physical attributes, the genetics of brain wiring is a long process that isn't exclusive to neither gestation or even childhood.

And while this wasn't a big point in the book at all, the author articulated something I have been thinking for a good while about group differences. Stereotypes often have a grain of truth. While for example differences between men and women are certainly amplified and distorted by our culture, there are differences nevertheless. The stereotypes seem to coincidence (they aren't completely random), but very often in an exaggerated manner. They end up this way because they are oversimplified yet effective heuristics to make predictions with little information. But they end up very off when applied to specific individuals. Trying to claim the stereotypes are completely inaccurate is not helpful because it is untrue. Yet, adhering to such stereotypes is also counter-productive as they most certainly distort reality with oversimplified schemas. The goal should be to clarify why the stereotypes are oversimplifications and also to judge individuals by themselves without group labels.

Overall it's a very solid book. If you're interested in psychological traits or genetics, I think anyone would really enjoy it and finish it with a much better understanding of the underlying science. If you are interested in both, then I doubt there is a book better done than this. There is often a trade-off in many of these types of books. Not describing the science enough vs being too technical, or getting to dragged into political controversy vs not preventing unfair criticism and misinterpretation. I think Mitchell nailed these trade-offs perfectly and wrote a deeply educational and enjoyable book about a fascinating topic. If you're new to neuroscience or genetics, I would recommend getting the paperback and not the audiobook. While I chose the latter, many of the topics I was already familiar with. If I wasn't, I think the beginning of the book, which gives the required technical background, would be difficult to follow. If you're new, it's worth having the opportunity to read it instead of listening so you can take your time and have better retention.

[Xavier · Rating 5 out of 5]

It took me many months to read this book, and while for some time I considered that a strike against it, I now think that was due more just to my reignited interest in reading fiction in that same time. Reflecting now, I have to say that this is an impressive book in both the number of areas it covers and the depth but ease with which it explains complex topics to the reader.

One idea that will stick with me from this book is that of developmental randomness. The general idea is that the initial differences in psychological traits between people are due in part to the randomness of the process by which the brain is constructed in the womb. DNA does not lay out an exact plan for brain construction, but instead acts more like a set of guidelines. This creates variation in precisely how different regions of the brain are wired within themselves and with other parts of the brain. This variation contributes to people’s baselines in psychological traits. Of course, neuroplasticity allows for the brain to change through experience, but the initial differences set out by genes and developmental randomness play a key role in giving each of us our unique nature.

[Uta Frith · Rating 5 out of 5]

This booked changed how I think about development and the interplay of nature and nurture.

[Miles · Rating 4 out of 5]

People who study the classic scientific debate between nature and nurture tend to reach some version of this conclusion: It’s complicated, both sides make significant contributions to human behavior, and we should never be too quick to attribute a particular outcome solely to genetic or environmental factors. Kevin J. Mitchell’s Innate doesn’t completely overturn this paradigm, but it definitely modifies it in ways that feel fresh and exciting.

Innate is a dense but accessible analysis of cutting-edge findings from genetics, neuroscience and psychology. Mitchell has a true talent for condensing complex scientific concepts into graspable prose, and includes many well-designed visuals to complement his research. His thesis posits not only that the existence of innate personality traits is inarguable, but also that these traits appear to have a larger impact on our selection of behaviors and experiences than previously thought. He explains:

"The debate about the relative contributions of nature and nurture to our psychological makeup is classically framed as a battle between these two forces, rather than, say, a collaboration. In recent times, this has turned into a proxy war, with genetics on one side and brain plasticity on the other, lately allied with the shadowy forces of “epigenetics.” If the brain can change itself, and if we can turn our genes on or off by our own behavior (which is what some proponents of epigenetics rather nebulously claim), then it seems we could reverse the arrows of causation––our psychology could dictate our biology, rather than the other way around.

"Under this scheme, nurture––whether this refers to parenting, experiences, or our own conscious psychological practices––can trump nature. It can overwrite the innate differences in our brains that arise due to genetic and developmental variation. In fact, what tends to happen is just the opposite––initial differences tend to be amplified due to the self-organizing processes of brain development and the fact that individuals select and construct their own environments and experiences largely based on innate predispositions. This is a radically different conception, where the processes of brain plasticity––the supposed instruments of nurture––align with nature instead." (81)

I found the first component of Mitchell’s argument––that innate predispositions exist and obtain from an individual’s genetic makeup––to be neither controversial nor unfamiliar. The second component, however, was much more novel. Mitchell zooms in on the highly probabilistic and unpredictable nature of brain development, whereby each human body physically constructs its brain according to a person’s unique genome:

"The complex machinery of the brain emerges from instructions encoded in the genome, but it is not mapped out like a blueprint––there is no one part of the genome that corresponds to one part of the brain or one type of nerve cell. It is more like a recipe, or a series of protocols, which, when carried out faithfully, result in a human being with a human brain. And, just like a recipe, no matter how detailed and precise it is, there will inevitably be some differences in the outcome from run to run––you can’t bake the same cake twice." (54)

This process, which Mitchell helpfully refers to as “prewiring” (as opposed to “hardwiring,” which implies genetic determinism), exerts a massive impact on a person’s way of seeing and interacting with the world. The descriptions of prewiring in Innate are quite intricate for a popular science book, but Mitchell does a commendable job of leading the reader through the major self-organizing layers of brain development, revealing a vast and impressive array of pathways through which each person’s genetic program builds a brand new and completely unique brain. Mitchell gathers these factors under an umbrella concept called “robustness,” with each person thrown into a genetic lottery that can increase or decrease chances of efficacious development:

"There is an unexpected consequence of the way developmental systems are designed, which is a paradoxical fragility to certain kinds of perturbations, especially mutations in developmental genes. The robustness that evolved to buffer noise and environmental variables means the system can also absorb the effects of many mutations affecting the components of the developmental programs. But not all of them…We all carry thousands of minor genetic variants and typically 100-200 major mutations. So none of us has a developmental program that is as robust as it could be. If you or I were cloned 100 times, the result would be 100 new individuals, each one of a kind." (77-8)

Importantly, although the development of each individual brain is subject to a wide range of variability (each recipe can bake many potential cakes), which brain ultimately gets “baked” appears to be either minimally affected or completely unaffected by factors outside the body––the traditional forces of nurture. This means that the “world outside” the body has little to no impact on the development of our innate predispositions, at least when a person undergoes normal, healthy development (the effects of adverse childhood experiences may represent a categorical exception). Furthermore, as stated above, it is Mitchell’s view that these same predispositions tend to be reinforced and compounded by our environments and experiences, rather than challenged or subverted by them. Whether this assertion will stand the tests of time and scientific scrutiny remains to be seen, but as a first stab Mitchell’s case is compelling and well-supported.

Assuming Mitchell’s thesis is correct, what are the implications of shifting the nature/nurture debate in this direction? First, it is critical to point out that Mitchell is not a genetic determinist who believes that nature is the only game in town:

"The claim is far more modest. It is simply this: that variation in our genes and the way our brains develop causes differences in innate behavioral predispositions––variation in our behavioral tendencies and capacities. Those predispositions certainly influence how we behave in any given circumstance but do not by themselves determine it––they just generate a baseline on top of which other processes act. We learn from experiences, we adapt to our environments, we develop habitual ways of acting that are in part driven by our personality traits, but that are also appropriately context dependent." (264, emphasis his)

So, we shouldn’t interpret these findings as nullifications of the traditional forces of nurture, but we also shouldn’t downplay the powerful role of nature. By and large, innate differences between people are not the products of conscious human choices; they are not particularly sensitive to our intellectual discoveries, cultural traditions, or ethical convictions, and instead are received from the statistical crapshoot of developmental robustness and the contingent whims of our biological history. The fact that we are a sexually dimorphic species is the starkest example of this, and Mitchell includes an entire chapter addressing the significant and undeniable differences between men and women. He also explores the nature of variations in human perception, intelligence and mental illness, putting forth his own spin on how innateness operates in each field of study.

I think Innate is a good and worthwhile book, but I would like to point out one area where Mitchell’s intellectual consistency seems to falter. In his last chapter, he claims that his point of view does not align with determinism––that his research shouldn’t lead readers to conclude that people don’t have free will. I think Mitchell does a fine job of avoiding genetic determinism and neuroscientific reductionism, but I think he fails to refute determinism in the more general sense. In fact, Innate contains some of the strongest arguments I’ve encountered that support the determinist position and undermine the commonplace concept of free will.

Mitchell tries to split the difference by acknowledging that our freedom is constrained by biology and that “free will doesn’t mean doing things for no reason, it means doing them for your reasons” (266, emphasis his). However, the entire rest of his book could be interpreted as an extremely detailed and convincing explanation of exactly how little “choice” people get in shaping their motivations and reasons for action. It seems unclear, then, how we are supposed to feel the kind of personal ownership over our motivations and actions that would confer a legitimate sense of self-determined freedom. It would be better to admit that there’s no scientific evidence to support free will, and to point out that this reality doesn’t require us to completely surrender our notions of personal and social accountability. Rather, we ought to utilize the nonexistence of free will as a bedrock motivation for a compassion-based overhaul of our institutional responses to aberrant and violent behaviors. Mitchell’s failure to make this move constitutes a lost opportunity.

I don’t need to agree with Mitchell about everything in order to appreciate his valuable contribution to these fascinating and consequential subjects. The best of these is perhaps the intellectual tools Mitchell provides for “reality-proofing” our expectations of ourselves and others. Since people arrive on Earth with well-developed and wide-ranging predispositional palettes, we must accept that human communities are a mosaic of profoundly variable perceptions, preferences and reactions to our ever-changing world. There is a strong limit to how moldable people can become, and we must adapt our models of growth and learning to promote achievable progress while also rejecting the project of human perfectibility:

"There is a power in accepting people the way they are––our friends, partners, workmates, children, siblings, and especially ourselves. People really are born different from each other and those differences persist…Denying those differences or constantly telling people they should change is not helpful to anyone. We should recognize the diversity of our human natures, accept it, embrace it, and even celebrate it." (269)

This review was originally published on my blog, words&dirt.

[P K · Rating 3 out of 5]

We read this for a neuroscience book club I co-run. Message me if you want our guide and thought questions :)

Caveat, I read Robert Plomin's Blueprint before I read this book, and so a lot of the mind-bending twin study stuff and how we're understanding heredity all wrong (like the influence of nature on nurture) was covered in Plomin's book (more compellingly imo), so that probably affected how engaged I was with this book.

This book argues that who we are (our personality, intelligence, perception, tendencies, and mental health) is not shaped by our genes in a simple way, but rather by how those genes guide the development of our brain. So the core thesis is that more of our nature is "innate" than we think, but that randomness in how development occurs plays a surprisingly large role. Like identical twins who share all their genes and have a very similar environment, can be pretty different. For example, if one of them is gay, there's only a 50% chance the other one will be gay. Mitchell argues that stuff like this is much more likely to be caused by developmental randomness when the brain is wiring and not due to different experiences.

The developmental randomness was the most novel and interesting part of the book I think. In Plomin's Blueprint, the missing variance was presented as "non-shared environment." Plomin emphasizes that these environmental factors are largely unsystematic and unstable, making them unpredictable and beyond our control. Like traits would be 50% heritable, but then the best polygenic score estimates would only explain 15% of the variability in a trait and scientists also couldn’t find any systematic environmental factors.

Mitchell on the other hand, attributes this variability in psychological traits that cannot be explained by genetics largely to stochastic variations in gene expression during brain development. Because many of the genes related to complex traits are mainly involved in development, with each gene only explaining a very small percent of variability in a trait, these differences are amplified over time.

In reality, it's very likely to be both, I think I was just biased to like the biological concreteness and quantifiability of developmental randomness more than the catch-all nature of "non-shared environment."

Overall, interesting read!

[Adam · Rating 4 out of 5]

Quite interesting book which looks not only at how a lot of our behaviour is innate but explains how this doesn't always mean something is genetic but also isn't always the product of our environment as we consider it.

I'm a big fan of The Blank Slate and this book really elaborates on those ideas. In that book it's argued that while many trades are largely genetic the "environmental" component is mostly random, not due to parenting and such, but doesn't really go as far to explain how. This book really gets into the weeds and details of how genes lead to behaviours, personality traits, intelligence and illness in ways that are not guaranteed by one's genetics but also not influenced by things like parenting.

Very thorough. Well explained. Some great ideas and powerful concepts.

[Jitse · Rating 4 out of 5]

Accessible account of the interplay between genetics, brain and behaviour. Good philosophical final chapter. Recommended! Full review in Dutch: https://zijstraatjes.wordpress.com/20...

[Luke · Rating 5 out of 5]

Excellent and insightful. A comprehensive description of the role of genetics and development in determining personal traits. The parts about the role of developmental randomness, as well as the diminishing effects of shared environment in adulthood were particularly fascinating.

[Hind · Rating 4 out of 5]

Good book.

[周 大為 · Rating 4 out of 5]

這是一本說明基因如何影響大腦，大腦如何影響個性的一本書。這本書給的知識很紮實，讓人可以了解人類的個性如何被大腦所影響。同時也可以了解大腦的各種機制是如何在運作，比如男女差異、智商、特質，遺傳與後天經驗的影響等等。我最喜歡的是書中最後結語所說的，各式各樣的大腦產生了各種不同的人格特質，這是自然的一部分，所以我們不必總是追求某種性格上的完美，而應該接受人們性格的多樣性。 頗有啟發。

[Donal Hurley · Rating 5 out of 5]

This is a really excellent book. I attended a public lecture by this author a couple of years ago on the subject and was very impressed. I'm even more impressed after reading this book. His writing style is clear, engaging and very accessible. He discusses what behaviours are innate, what innate itself really means, he backs all the information with evidence and discusses the implications of what we know. One major discovery for me was that innate includes not only genetic variation between people but also a part that is due to random developmental variation. I would have to say this is one of the best science books I have ever read.

[Paul Spence · Rating 4 out of 5]

The author advances answers and explanations for many of the fundamental questions which vex clinicians such as myself. The difference from most such fare is that this guy knows what he’s talking about. He really really knows his stuff.

Two aspects make this book stand out. The author demonstrates the infallible sign of true mastery of the subject of discussion - the ability to use plain English, and explanations by analogy, to convey complex concepts to also-ran readers like me.

That feat is allowed in part by the author’s command of related contemporary psychology, and philosophy. The insight on show, in those areas, is deeper than that displayed by many current loudmouth professional psychologists and philosophers.

The most important concept expounded, the most important fact for any clinician reader to grasp, is that of the many-to-one and one-to-many relation between genetic variations on the one hand, and clinically defined entities such as autism and schizophrenia, on the other. Autism can be caused by many different genetic variations; because it is not really one disease/disorder. Whereas one genetic variation which causes autism in one individual will cause a different ‘condition’, or nothing at all, in another individual.

But there’s heaps of other important, interesting stuff too.

Complaints? Well, I could point out that the book does not contain any sophisticated examination of the construct of ‘ADHD’, only passing mentions. This is almost certainly because the author has spent no time in his academic life, examining the entity himself. This in turn indicates that the author isn’t stupid, since examination of the quasi-entity currently called ADHD is obviously a dead end which no amount of attempted sciencing will add to. But I would have enjoyed the book even more if the author had wasted a year or two of his academic life before he realised that, and written of his revelation - see above about his not being stupid, however.

Also, I listened to the audiobook. I understand the choice of a fairly posh sounding English narrator; he does an excellent job. Americans can’t understand most Strine (unadulterated Australian accent and vernacular); only an enlightened minority would make sense of Full Irish Narration.

But still it seems a shame - key observations, such as the following contained in Chapter 9, would have sounded even more compelling if uttered by the likes of Dylan Moran: “Men also have thicker skulls, especially in front, which may reflect the fact that we like to punch each other in the face a lot.”

[Per Kraulis · Rating 5 out of 5]

This is a clear and well-structured discussion of the current state of knowledge about what makes a human mind. It carefully describes from where differences between humans arise, and how genetic and environmental variation can play out in different ways. The main message is that genes provide a set of potentials, or propensities, for how the organism can develop depending on the environment. Sometimes the genes limit the possible panorama of outcomes very tightly, sometimes only slightly, and sometimes a small set of possible outcomes are available. Importantly, in the latter case, the effects of pure chance can become crucial: if a system is set up to allow a divergence in development - a fork in the road, as it were - then the final result cannot be said to be neither "in" the genes nor determined by the environment. And yet it is innate.

I have a minor quibble: In a few paragraphs, the language has a few too many bio-jargon terms, which ought to have been edited away.

In the last pages, Mitchell makes a brief visit in the philosophical mine-field of determinism. He states that his view does not undermine free will, but he rejects dualism (the view that brain and mind are different). But he also writes "The mind is not a thing at all - at least, it is not an object. It is a process, or a set of processes - it is, simply put, the brain at work."

This seems to me to beg the issue. When he continues to affirm that the logical content of a thought - its meaning - can have a casual power in and of itself, by being an emergent phenomenon, then he seems to me to be much more of a dualist than he wants to admit. Now, I have absolutely no problem with this at all. The notion that the content of thoughts can have a causal power seems to me to contradict material determinism. The dualism (or rather theory of Worlds 1, 2 and 3) that Karl Popper espoused in "The Self and Its Brain" (with John Eccles) is, in my mind (!), a highly fascinating attempt at solving the mind-body problem.

[Shima Ghaheri · Rating 3 out of 5]

This book very clearly explains the relationship of innate characteristics as genetically stablished framework modified by the complexity of experience laid down on the coded framework. The obvious nature of differences between people, peoples, and genders causes some people a great deal of angst. It shouldn’t. This text helps explain the differences without suggesting determinism or eugenics. There are no claims of value hierarchy, but instead a call to relish and celebrate the variances in the human innate. Quick read.

[Peter P. · Rating 5 out of 5]

Kevin Mitchell, an associate professor at the Smurfit Institute of Genetics at Dublin's Trinity College, has written, in my view, the definitive text on the question of Nature versus Nurture. Supported by research and science, Mitchell expertly lays out the case for the power of innate traits and the degree to which we can or cannot overcome those predispositions. He explores how traits lead us to seek out environments that reinforce the traits and the degree to which parenting influences behaviors. Brilliantly done.

[Adam Calhoun · Rating 4 out of 5]

Excellent overview of the modern consensus on how genetics influences behavior and individuality. Written in a way that does not condescend to the reader, it is technical and enjoyable while also being readable by anyone interested in the material. Very much worth reading whether you are a new to the ideas or a scientist working in the field.

[Yanick Punter · Rating 4 out of 5]

I enjoyed this. Some parts were underwhelming, while others were really good. There was a discussion on geniuses and IQ but not creativity - which I would have liked. I was familiar with some of the information in the book.

I recommend watching this interview by the Dissenter:
https://www.youtube.com/watch?v=VBc9A...

[Ben Zimmerman · Rating 4 out of 5]

This book takes on the Nature vs. Nurture debate, but focuses on the unique perspective that who we are, our personality, intelligence, perception, tendencies, and mental health, is not shaped by our genes in a simple way, but rather by how those genes guide the development of our brain. So the core thesis is that more of our nature is "innate" than we think, but that randomness in how development occurs plays a surprisingly large role.

One of the most counterintuitive and powerful points that reflects this are studies done on identical twins with identical DNA and nearly identical environments and yet are meaningfully different in core traits. One of the striking examples to me was that of homosexuality. If you cloned someone who was gay 100 times, on average, only about 50 of those clones would be gay (!). I think that a common way to think about this fact is that there must be important early life experiences that causally determine this outcome. Maybe one twin spent a lot more time looking at Superman's rippling abs in comic books as a kid or something. But Mitchell argues that this is much more likely to be caused by developmental randomness when the brain is wiring, that actually has very little to do with learning or life experiences.

Another important theme focused on misconceptions about heritability, which was also a major focus of another excellent book on this topic, Blueprint, by Robert Plomin. One of these misconceptions is that what we call "nurture" is often shaped by nature. People gravitate towards environments that match their innate tendencies, and so the heritability of traits tends to increase with age, rather than decrease, against many people's intuition. Also, heritability of traits tends to increase in populations that have more equality in opportunity. So, for example, the heritability of intelligence is higher in countries where everyone has similar access to education.

In this book, the most interesting way that this manifested to me was when Mitchell was discussing innate sex differences. Mitchell discusses the paradoxical finding that sex differences in psychological traits, including personality, are often larger in more gender-equal and resource-rich societies, which seems counterintuitive. Many people assume that as cultures become more egalitarian and supportive, gender differences should diminish, but instead the opposite pattern emerges. Mitchell reasons that in more egalitarian societies, people have more freedom to choose their own careers, hobbies, lifestyles and emotional expressions that align with their intrinsic dispositions. These dispositions, which are shaped by innate wiring, are then amplified.

Overall for me, this book really changed the way that I looked at the nature vs. nurture question because it revealed a sort of "third variable" of developmental noise, which makes a lot of sense, given that so many of the genes related to complex traits are mainly involved in development, with each gene only explaining a very small percent of variability in a trait. In Blueprint, I remember the "missing variance" being presented sort of like an unexplained mystery. Like traits would be 50% heritable, but then the best polygenic score estimates would only explain 15% of the variability in a trait and scientists also couldn’t find any environmental factors, that when combined with each other, explained anything close to 50% of the variance. I was very satisfied with the idea that developmental randomness could account for a significant amount of that missing variance.

Another fascinating theme for me in the book was the idea of developmental robustness and its relationship to mutational load. On average, we each carry about 200 severe mutations that negatively impair the function of some gene. But since we evolved in the context of this problem of mutations, we also seem to have a high level of development robustness. There are multiple processes that can help compensate for the things that happen to not be working optimally, especially in guiding the initial development of our brains. Mitchell actually suggests that part of the reason that we might have a relatively high degree of mental illness is because, as a species, our brains changed so rapidly so recently that they might not have adapted enough robustness yet. This way of conceptualizing genetic origins of mental illness makes a lot of predictions that seem to be true. Many genes are involved in mental illness; the genes involved in mental illness significantly overlap between different mental illnesses even though the phenotypes are different; and also, mental illness doesn't seem to be ultra-heritable, like if you have schizophrenia, there is only ~50% that your clone would also have schizophrenia.

The final chapters do the obligatory wrestling with the implications. If people truly differ in innate capacities and tendencies, what does that mean for education, equality, free will, and moral responsibility? Mitchell strongly argues that acknowledging individual differences should promote compassion and support, not discrimination. A society that assumes everyone starts from the same baseline sets many people up for failure.

[Emil O. W. Kirkegaard · Rating 4 out of 5]

review is on blog