The Dependent Gene: The Fallacy of "Nature vs. Nurture"

by David S. Moore

A masterful guide to human development that redefines the nature versus nurture debate

A much-needed antidote to genetic determinism, The Dependent Gene reveals how all traits-even characteristics like eye and hair color-are caused by complex interactions between genes and the environment at every stage of biological and psychological development, from the single fertilized egg to full-grown adulthood.

How we understand the nature versus nurture debate directly affects our thoughts about such basic issues as sex and reproduction, parenting, education, and crime, and has an enormous impact on social policy. With life-and-death questions in the balance surrounding stem-cell research, cloning, and DNA fingerprinting, we can no longer afford to be ignorant of human development. An enlightening guide to this brave new world, The Dependent Gene empowers us to take control of our own destiny.

Genres: Biology, Science, Psychology, Nonfiction

320 pages, Paperback

First published January 16, 2002

About the author

David S. Moore is a Professor of Psychology at Pitzer College and Claremont Graduate University in Southern California. He received his B.A. in psychology from Tufts University and his M.A. and Ph.D. in developmental and biological psychology from Harvard University; he also completed a postdoctoral fellowship at the City University of New York. He is a developmental cognitive neuroscientist with expertise in perceptual and cognitive development in infancy. His empirical research has produced publications on infants' reactions to infant-directed speech, on the development of spatial cognition, and on infants' rudimentary perception of numerical quantities. His theoretical writings have explored the contributions of genetic, environmental, and epigenetic factors to human development. His first book, The Dependent Gene (2001), was widely adopted for use in undergraduate education, was translated into Japanese, and was nominated for the Cognitive Development Society's Best Authored Volume award. His new book on behavioral epigenetics, The Developing Genome, was published by Oxford University Press in 2015.

Reviews

[Brandon · Rating 1 out of 5]

(This review is taken from my Amazon review)

The author of this book misrepresents the nature of the conclusions drawn from behavior genetics and oversimplifies how they do things. He writes as if they have not made any progress since Francis Galton founded the field and he repeatedly equates it with eugenics.

For one, sociobiologists and behavioral geneticists are well aware that everything occurs via gene-environment interactions.

Secondly, he completely fails to substantiate the claim that it is absurd in theory to separate gene and environment in concept. Of course you can separate them in concept. I have stands of DNA in me. There is an environment outside of me. Those are completely different things. Of course what he means is a bit more specific. He means that when discussing a phenotype it is impossible to separate the contributions made by genes and those by environment. Except that it is. Even when the environment completely changes the phenotype via epigenetic modifcations, we know exactly how this is done. There's nothing mysterious or inseparable or irreducible about it.

Here's some examples of the inaccuracies and straw man attacks in the book.

On page 41 he writes that heritiability estimates tell us about what causes *variability* in traits, but not what causes traits themselves. Fair enough, but he uses this to argue that NOTHING is genetically determined. What then about diseases like cystic fibrosis where the specific alleles and conditions for their expression are known? It follows a perfectly predictable autosomal recessive pattern of inheritance. So, how exactly is Moore's dynamic developmental perspective supposed to undermine the fact that C.F. is genetically determined?

"What is the value, then, of knowing what accounts for differences among people in a unique situation, if it is within our power to easily change situations?" For one, that's assuming we DO have the power to change how a gene is expressed just by changing a situation. Certainly for certain behavioral traits this is possible, but otherwise, he's basically just saying "Lalalalala I can't hear you geneticists I can't hear you lalalala" He COMPLETELY misses the point here of scientific understanding. Sometimes the goal is not just to understand what accounts for differences, but to understand for what accounts for SIMILARITIES across different situations over time.

He goes on to say that "for behavior geneticists, the goal is to predict the appearance of traits by looking at genes -- only genes! .... knowing what affects non-genetic factors have on a trait's appearance is simply not of interest to behavior geneticists, who consequently just ignore these factors." (pg. 46) That's completely and utter nonsense. There is TONS of research investigating the role environmental factors have on gene expression. Being that I have a stack of research papers right next to me, allow me to list just a few.

- Genetic and Environmental Influences on Human Psychological Differences, Bouchard & McGue, 2003
- Reconsolidation involves histone acetylation depending on the strength of memory, Federman, Fustinana, & Romano, 2012
- Epigenetics, brain evolution, and behaviour, Kervene & Curley, 2008
- Epigeneitc regulation of nervous system development by DNA methylation and histone deacetylation, MacDonald & Roskams
- Epigenetic Gene Regulation in the Adult Mammalian Brain: Multiple Roles in Memory Formation, Lubin, 2011
- Epigenetics: Behavioral Influences on Gene Function, Part 1. Maternal Behavior Permanently Affects Adult Behavior in Offspring, Orgen & Lombroso, 2008

I have more, but you get the picture. All of those studies involve understanding the roles genes play in biological function and take into account environmental factors, not just as measurement error or what can't be accounted for by genes, but HOW the environment works with genes. So his claim that behavior geneticists have no interest in these things is a lie and a low brow attack on the field.

Of course, there's also the famous prairie vole study. I'll leave it to you to look it up, but it can be found in Braintrust: What Neuroscience Tells Us about Morality and Animal Behavior: An Evolutionary Approach, 8th Edition.

The point is that no one thinks everything is determined by genetics. I recommend taking a look at the book The Triumph of Sociobiology. In it there is a chapter called Sociobiology and Genes and there is a section within called "The Myth of The Genetic Determinist". The author discusses a lot of the same things that David Moore does, except he doesn't draw scientifically irresponsible conclusions. Sadly, this book is the same sort of crap we used to see from S.J. Gould, Richard Lewontin, and Leo Kamin -- all otherwise great scientists who were scared to death of the implications their fields might have on their socio-political views, so they did everything they could to twist scientific fact to fit their social concerns.

[Caroline · Rating 4 out of 5]

I didn't know whether to love or hate this interesting and frustrating book. Moore makes an excellent case for the way development in the environment influences the expression of the raw genetic material in our chromosomes, with many useful examples. Part V was the most satisfying, as he laid out the reasons why a developmental perspective should put to rest any ridiculous public policy based upon the idea of superior or inferior genes. It's puzzling and frustrating that 20 years after the book was published, the media is still telling us that the gene for this or that has been identified, as it's so much more complex than that, and even if a gene really does point to a certain result, other factors influence whether and how that gene will be expressed in the person. And his repeated emphasis that environmental impact on development happens before birth is also a useful corrective. I kept waiting for "blame the mother" for faults in her baby crap, which fortunately never came.

Given his healthy skepticism about the role of any given gene in any given result, he is annoyingly willing to put forward a study here and a study there that points to a determinative role for a given environmental factor. The one that was most dangerous was the one that suggested (I think in the 1980s) lower testosterone levels in maternal blood during pregnancy lead to male offspring being gay. This implies that gay men are just testosterone-deficient, stunted males, which is ridiculous on its face and suggests the possibility for all kinds of abuse. I believe if he is committed to skepticism of such studies when they suggest genetic origins for traits, he should have been skeptical of that one. There was also discussion of studies in the 1990s that indicated maternal malnutrition could contribute to the expression of a genetic legacy of schizophrenia - if this is the case, shouldn't countries that have experienced severe famine have a gigantic population of people with mental health problems? and yet you never hear about plagues of schizophrenia or bipolar disorders in Biafra or in the famine Irish or the many other places in our world that people don't get enough to eat.

I found his discussion of PKU unsatisfying. I first heard of this about 30 years ago when a friend had a baby and they found she had PKU - she couldn't drink any sodas that are labeled for phenylketonurics, because she was unable to break down the phenylalamine in them (hope I'm spelling these things right!). He plays games with definitions here. My understanding is that PKU means that due to something genetic, a person's body is unable to make the proteins needed to break down phenylalamine - it is the inability to break them down. He decides that he's going to define PKU as the syndrome of disease that results from ingested and unprocessed phenylalamine, instead, because that lets him say that in the absence of phenylalamine in the person's internal environment, that disease does not develop. Yes, PKU is detected not by genetic testing but by analysis of newborn urine. But he continually points out that genes do nothing except make proteins, and this protein is missing in this person, who is a phenylketonuric because of this lack. Changing the definition, which he justifies by saying that not everyone with HIV has AIDS, is just a word game.

And I wish he had tackled the simplest genetic thing that we all learned in high school biology, about dominant and recessive genes, and addressed the simplest example, blue eyes. Yes, people with PKU who do not avoid consumption of phenylalamine develop a loss of pigmentation which includes having blue eyes despite being genetically coded for brown eyes. But that doesn't mean all eye color is environmentally determined. To really address the common person's understanding of genetics, he needed to start at our level and talk about why my brother has blue eyes and I do not - and saying that if I were injected with some kind of chemical my eyes would fade to blue is not enough. How is it that so many male descendants of Queen Victoria had hemophilia? It's not my understanding that people with the genetic makeup for hemophilia can still not have it? And my daughter carries the gene for beta-thalassemia and if she had a child with someone else who carries it that child would be likely to get two copies of the gene and need continual blood transfusions to live. Again it's not my understanding that you can have the genetic makeup for this disease and not actually have it. And how is it that my brother looks just like my mother's brother, and I have my mother's nose? - is it being suggested that if we had developed in a different environment we would have had different noses? I wish he'd begun his discussion at that level.

By not addressing these things, which are common knowledge among ordinary people, head-on, he contributed to the feeling I came away from this book with, which is that genes don't determine anything. I believe he knew he was creating this impression, as once in awhile he would throw in a statement that oh yes, genes do have a critical role, but by not addressing the most simple examples he weakened the uptake of his argument. Which is unfortunate, because this is an early articulation of something we all need to believe about the foolishness of the idea of superior genes.

A favorite moment for me resulted partly from the randomness of typography. After repeatedly and effectively demolishing the idea of heritability estimates, he writes, "Heritability estimates continue to be useful in helping to predict the outcomes of selective breeding programs (because we can hold environments constant in these situations). As such, these estimates continue to be of practical use to both farmers and [turn the page here] Nazis (or eugenicists, more broadly)." Cheers to the layout expert who put the page turn there!

[ab-drizz · Rating 5 out of 5]

Read this book for a class and loved it! While the ideas in it are a little more complex and can be hard to follow at first, once you figure out the writing style the book becomes really enjoyable! It completely changed my perspective on ignorance in genetic determinism. Moore calls out the misconceptions in society. He also highlights the importance of agency and personal responsibility in development. This is a great introduction to the developmental systems perspective (DSP) and I think everyone needs to learn about it, or in Moore's words "the emergence of such a change in society's focus would be revolutionary!"

[Ab · Rating 4 out of 5]

Really liked the book, although I'd love to hear what mainstream geneticists think of it: I don't know the field enough to judge the quality of evidence presented. The main idea---that it is both Nature & Nurture---is of course correct. I learned a lot.

[Lizzy Cichoski · Rating 3 out of 5]

I felt like this was very interesting at times but pretty redundant. Moore argues strongly for a developmental systems perspective in research, and I agree with him, but he repeats his ideas often. Could be condensed.

[Tony duncan · Rating 5 out of 5]

This is another great book on the importance of understanding development in order to understand human nature. I am constantly amazed at how most people I know are unwilling to look at the concepts of human nature. This book is a direct attact on the almost universally accepted proposition that genes determine who we are. Even though these ideas have been around for a generation, the media is still filled with reports about how scientists have discovered "the gene for" fill in the blank.
And this is not just an academic concern. the consequences of this sort of thinking are staggering, Because they encourage the paradigm that people are who they think they are - end of story. That once their personalities are established, then there is not much point in going against the grain or even looking at feelings and behaviors, because "that is just who I am".
This book is written by a developmental psychologist, who really understands genetics, development AND psychology, and how they are interdependant. interestingly I was reading "The World in Six Songs" that, while brilliant and extremely important in its own right, is sorely wrong about some importnat issues because the author apparantly has no understanding about the modern science of evolutionary developmental biology. Reading the two books together showed just how easy it for even brilliant established scientists to make huge assumptions that are likely wrong because they believe that genes "determine" traits.

Moore gives a great history of developmental biology, and explains how now it has really synthesized knowledge in all the relevant fields, and how exploring the specifics about all aspects of development is essential before one can come to ANY conclusion about how plastic any behavior or even strictly biological trait is expressed. And most importantly looking at all the factors can help determine how to change traits.

In the book Moore gives increasingly relevant examples, such as hair color. Phenylketanuria, mating behavior, and even fear of snakes, as examples of traits that are still considered to be genetically determined, yet, when looked at from a developmental perspective, are not only NOT hardwired, but are extremely environmentally pliable.

His book takes one step by step in very plain language through a clear understanding of how organisms actual form, and how genetics actually works. he gives very clear explanations for the complex interaction between DNA, RNA, Proteins, and the multiple hierarchies of environment, from the the level of the cell to sunlight, and he shows how the complex interactions result in the formation of complex organisms, WITHOUT there being ANY blueprint.

I highly recommend this to everyone that wants to really understand how to understand who we really are

[Matt Kammeyer · Rating 4 out of 5]

I would never have simply picked up this book and read it--it was required reading for a child development class--but I am very glad that I did read it. The book is very accessible, especially considering the topic, and full of interesting examples that drive the reader forward rather than distract or obfuscate. Anyone who has ever been even mildly interested in the topic would enjoy reading this.

[Alex · Rating 4 out of 5]

Really made me want to read more about embryology - a confirmation on what you might think why clones are never exactly like the original and a bunch of other interesting anecdotes. 25 years ago, when I was studying biology, one of my teachers was telling me: at some point in the division of a fertilized egg, differentiation happens and we don't really understand much about it. It was still the case in 2001 when that book was written and I bet it still is.

[diana · Rating 2 out of 5]

I think this book brings up some really interesting points about what exactly constitutes environment, but I definitely had to skim through it. However, for someone without any background in molecular biology or genetics, it may be right on the money.

[Dawn · Rating 4 out of 5]

One of the most articulate and accessible books I've read on the fallacy of Nature v. Nurture.

[William · Rating 2 out of 5]

Reads like a textbook but at the conclusion I felt that I had not added to my understanding of the subject.