Kevin Mitchell (2018) “Innate
– How the Wiring of Our Brains Shapes Who We Are”
[This repeats and adds to relevant content from an earlier partial review.]
Several of the more important books I’ve read recently have felt mostly like syntheses and restatements of things I already felt I knew one way or another – Solms’ “Hidden Spring“, McGilchrist’s “Matter With Things” and Sigmund’s “Exact Thinking in Demented Times” (say) – and I’ve gone straight into gutting them for content to add to my own theses.
Reading “Innate” however I found several levels of details new to me. Highly recommended therefore as an educational read – very matter-of-fact / common-sensical style, free of hyperbole, with its only agenda focussed on increasing understanding.
For example, on understanding that pre-wired traits are not hard-wired (the extent to which there’s plasticity) and that genes & DNA really do drive most of the (genetic) process of development of the human individual – traits, propensities, capabilities of brain and mind – without being reductively deterministic.
“Wiring” as the processes – not just the resultant paths– by which neurons and other structures seek and form connections at all stages in the process, that once in a unique development lifetime process of that individual.
From conception / fertilisation to our early 20’s, birth itself is just one point in the complex processes of development in a multi-layered landscape of time and place. So “innate” includes heritable genetic variation from parental DNA and “de novo” mutations specific to the particular gametes, as well as the unique pre-birth experience of the individual. Why sexual reproduction and the enormous starting asymmetries (size, number and lifetimes) between the gametes (egg and sperm) and the sex-specific chromosomes (XX and XY) is so important to our success as “the clever ape”.
No shying away from the facts that as a species, we homo-sapiens are special in many important respects.
Mitchell is also very good on distinguishing between individuals and population distributions – and sub-set distributions – when it comes to human nature(s) and the value in understanding these without being in any way prescriptive or limiting of individuals. Makes it easy and natural to talk about differences – not least for example sex/gender differences (and even sexual preferences), free of “woke” political distraction. A whole chapter on many different sex differences, in both normal cases (eg things vs people) and in the prevalence of atypical conditions (eg autism, schizophrenia, bipolar). For sure there are strong environmental / cultural interactions with these, but great danger in denying and failing to understand the real differences. Difference – differences that make a difference – is a strong theme.
The complexity of the many feed-back and feed-forward loops in the nature of nurture – and the scale of the numbers involved – in neural and mental / behavioural development are endlessly fascinating and yet, as I say, presented in a very readable and digestible style.
The combination of functional and developmental flow descriptions and system / sub-system connectivity diagrams obviously appeals to my original cybernetics systems-thinking perspective. Mitchell’s book is an example of how powerful it is and why it is so important that such thinking is properly rehabilitated in a world of human affairs that rejects the mechanistic impression of our 20th C electro-mechanical computing machines. Original cybernetics was always about human governance, even the word “machine” in the Turing sense is a valuable abstraction before any physical embodiment.
The verb “shape” is so much more architectural than the over-simple determine when it comes to the rich complexity and multiplicity of human traits and capabilities arising from our genes. One feature of the systems-architectural view is that one can properly choose to ignore details which are not relevant to the behaviour of any given sub-system and yet assemble a functional view of the complex whole. Mitchell brings a very particular set of details applicable to the ideas of genetic and/or innate, pre-wired and/or more-or-less hard-wired or plastic when it comes to who we turn out to be.
Many highlights of interest to my own agenda:
An obvious one is that infamous Pinker “Blank Slate” finding, much quoted here since 2002 about the rough ratios of influence in personal traits development (nature vs nurture vs culture – Lewens) between:
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- genetics (~30-40%),
- parenting & formal teaching (~10-20%) and
- wider social, environmental & peer-group experience (~50-60%).
Mitchell shows that the “environmental” aspect is so misleading – actually very like the content<>context distinction in knowledge generally. (ie context is just more content, but often in meta-layers removed from the current content). At any point, our existing brain / mind IS the context for our ongoing content development. We are a large part of our own environment. That large mysterious part of our development is mostly indirectly – many layered loops of influence – driven by our own genes and other DNA including those we share with our parents and siblings.
Nurture and culture are natural processes too.
Another, without specific references, very reminiscent of both Solms and Pirsig in terms of “the subjective experience of the environment that matters” – “affective or emotional states that drive initial behavioural responses” – experience in terms of categorical good / bad qualities – “to learn from things … which we know only because they felt good or bad to us, because they were tagged with subjective, affective value.”
And, as with the ubiquitously contentious differences like sex and sexual preference mentioned above, differences like racial groups are also addressed. A passage on why, whilst such mental differences are real, these are “multiple traits affected by the genetic variants in hundreds and thousands of genes which often also affect other traits” – “this will tend to constrain the possibilities for change” and “directional selection (within the species) will fight a losing battle against mutation, which will instead constantly generate diversity within groups. There would need to be an extremely strong – [external, eugenic] – selection force to drive stable group differences”.
And so many more annotations for future reference, not to mention the various graphical summaries.
Kevin Mitchell’s Innate manages to be both broad in scope and detailed in example content, whilst remaining readable and informative. Even without the strong fit with my own cybernetic agenda as the initial reason to pick it up, it was a positively enjoyable read. Highly recommended.
[End]
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[Post notes:]
From Kevin Mitchell’s own tweeted “Public Service Announcement” later the same day:
Genetics as a science is not about genes causing traits. It’s about how *variation* in genes causes *variation* in traits.
So, it’s necessarily reductive in its methodology. But that doesn’t mean geneticists think that specific genes produce specific bits of the organism or characters all by themselves
Making an organism requires the whole genome, in the context of a fertilised egg cell, in a permissive environment
But specific variations in DNA sequence can nevertheless cause specific phenotypic differences (all else being equal)
Note that that also does not imply a one-to-one mapping (in either direction) between specific DNA variants and specific traits – most such relationships are highly complex
Developmental biologists try to understand how the whole organism is put together, guided by the information in the genome.
That’s a necessarily holistic exercise, but it can be informed by results from reductive experiments (like knocking out one gene at a time and seeing what happens to development)
The tricky bit is integrating these two perspectives! (And remembering that using reductive methods does not commit us to reductive theories!)
That pesky term “causation” in the first tweet. And reminds me of Dan Dennett’s “greedy reductionism” warning. It’s OK to use reductive methods to understand the parts at any and all levels, but don’t forget to re-assemble the holistic whole – complex system of systems – before claiming causal explanations.
PSA: genetics as a science is not about genes causing traits. It’s about how *variation* in genes causes *variation* in traits.
— Kevin Mitchell (@WiringTheBrain) May 31, 2022