Dr Paul St John Smith reflects on his personal journey and unpacks some of the most common misconceptions surrounding evolution-based thinking in psychiatry.
As a late career psychiatrist, the lack of progress in treatment as well as our system for defining/diagnosing has led me to believe our conceptualization of psychiatric illness requires a fundamental shift. This approach seems right to me. I remember learning about the hunter vs farmer approach to considering adhd years ago which resonated both with me and my patients. The cliff edge model is the latest theory I find particularly interesting.
I’ve loved having a career where considering fundamental questions about human consciousness is at the forefront. No other medical specialty comes close.
"Evolution occurs at the population level, not the individual level."
To be clear after reading Robin Dunbar's book "An Introduction to EV" many years ago I have been a proponent of EV. It made sense as I failed to see why the brain an evolved organ was not subject to evolutionary pressures at the micro and macro levels, for all the reasons you have outlined.
But I have an issue, imho I think it fundamental that evolution acts on the individuals within a group. If the individual's overall fitness allows them to pass on a benefitting gene to offspring (this is not a certainty) it can gain traction become a dominant trait, evolved behaviour and benefit the group as a whole.
Or conversely in some cases it could have a proximate advantage but if an environment changed, a noose around the individual and the groups collective neck.
In my belief evolution can only occur at the population level, and individual's genes do not change across their lifetime with mutations being the exception:
E.g. If a mutation for antibiotic resistance arises in one bacterium, it’s just a mutation. If it spreads through reproduction and becomes more common in the whole bacterial population, that’s evolution.
Although evolutionary pressures act on individuals/genes, evolution itself occurs at the population level.
I'd love to see more on this topic from open-minded experts. What the author writes about -- hostility to new ideas -- I see often in the autism field, unfortunately.
This is fascinating and a subject area that I have been interested in for decades, although only as a layperson.
Do you know if there are any recorded studies for the village of Oberammagau in Europe which escaped the Bubonic Plague and so could provide a useful "before and after" for the way humans have evolved post pandemic from the middle ages?
Thank you for the article, well written and comprehensive. However, this statement caught my attention and to which I would appreciate a clarification:
"There is no evidence to suggest that evolution is guided by a teleological force or purpose."
My understanding is that all organisms share a common teleological goal that is Survival. Even unicellular organisms share this same goal, and multicellular organisms like mammals add another teleology to this, Reproduction. So it seems to me that survival and reproduction are the overarching teleologies of evolution, and there is plenty of evidence suggesting this.
You claim: "evolution does not have a predetermined goal or endpoint". Seriously? I was under the impression the predetermined goal was reproduction... Survival until procreation had been accomplished (possibly a bit longer to ensure survival of offspring and their survival to reproductive age). You're seriously upending all of evolutionary theory - at least what I was taught at University biology? If transmission of genes to the next generation is not the endpoint, you need some evidence!!! Not just unsupported claims which just sound like yet another ignoramus with a pulpit...
Quite apart from which, nobody asks why the genes for x,y,z physical illness exist... At least not the ones that have hundreds of genes worth of polygenetic inheritance, which is the case for psych illnesses. If you come up with a credible rationale for the evolutionary inheritance of osteoarthritis, let me know! It's a fool's errand. Nobody is doing the research, because in the general medicine world, they know that evolutionary medicine is irrelevant. It's irrelevant to psychiatry too.
As a late career psychiatrist, the lack of progress in treatment as well as our system for defining/diagnosing has led me to believe our conceptualization of psychiatric illness requires a fundamental shift. This approach seems right to me. I remember learning about the hunter vs farmer approach to considering adhd years ago which resonated both with me and my patients. The cliff edge model is the latest theory I find particularly interesting.
I’ve loved having a career where considering fundamental questions about human consciousness is at the forefront. No other medical specialty comes close.
Hi Paul,
Thanks for your comments and stopping by, great to hear the evolutionary approach has been useful.
Not an expert.
"Evolution occurs at the population level, not the individual level."
To be clear after reading Robin Dunbar's book "An Introduction to EV" many years ago I have been a proponent of EV. It made sense as I failed to see why the brain an evolved organ was not subject to evolutionary pressures at the micro and macro levels, for all the reasons you have outlined.
But I have an issue, imho I think it fundamental that evolution acts on the individuals within a group. If the individual's overall fitness allows them to pass on a benefitting gene to offspring (this is not a certainty) it can gain traction become a dominant trait, evolved behaviour and benefit the group as a whole.
Or conversely in some cases it could have a proximate advantage but if an environment changed, a noose around the individual and the groups collective neck.
Hi Keith,
Thanks for your comment there.
In my belief evolution can only occur at the population level, and individual's genes do not change across their lifetime with mutations being the exception:
E.g. If a mutation for antibiotic resistance arises in one bacterium, it’s just a mutation. If it spreads through reproduction and becomes more common in the whole bacterial population, that’s evolution.
Although evolutionary pressures act on individuals/genes, evolution itself occurs at the population level.
I hope that helps
Thanks again
Thanks for this excellent piece! Like the other commenter, I'm a layperson interested in these topics. I hit on evolutionary mismatch theories and research as they pertain to neurodivergence here: https://strangeclarity.substack.com/p/evolutionary-mismatch-just-one-part
I'd love to see more on this topic from open-minded experts. What the author writes about -- hostility to new ideas -- I see often in the autism field, unfortunately.
Hi Laura,
Thank you for your comments, it's wonderful to see your article and substack - wishing you all the best
This is fascinating and a subject area that I have been interested in for decades, although only as a layperson.
Do you know if there are any recorded studies for the village of Oberammagau in Europe which escaped the Bubonic Plague and so could provide a useful "before and after" for the way humans have evolved post pandemic from the middle ages?
Hi Shirralee
Thank you for your comment, not to our knowledge but please do let us know if you find something!
Are you familiar with the story, at all?
Thank you for the article, well written and comprehensive. However, this statement caught my attention and to which I would appreciate a clarification:
"There is no evidence to suggest that evolution is guided by a teleological force or purpose."
My understanding is that all organisms share a common teleological goal that is Survival. Even unicellular organisms share this same goal, and multicellular organisms like mammals add another teleology to this, Reproduction. So it seems to me that survival and reproduction are the overarching teleologies of evolution, and there is plenty of evidence suggesting this.
Or am I missing something?
You claim: "evolution does not have a predetermined goal or endpoint". Seriously? I was under the impression the predetermined goal was reproduction... Survival until procreation had been accomplished (possibly a bit longer to ensure survival of offspring and their survival to reproductive age). You're seriously upending all of evolutionary theory - at least what I was taught at University biology? If transmission of genes to the next generation is not the endpoint, you need some evidence!!! Not just unsupported claims which just sound like yet another ignoramus with a pulpit...
Quite apart from which, nobody asks why the genes for x,y,z physical illness exist... At least not the ones that have hundreds of genes worth of polygenetic inheritance, which is the case for psych illnesses. If you come up with a credible rationale for the evolutionary inheritance of osteoarthritis, let me know! It's a fool's errand. Nobody is doing the research, because in the general medicine world, they know that evolutionary medicine is irrelevant. It's irrelevant to psychiatry too.