I haven’t thought about the possible relationship between SLEEP DEPRIVATION and ADHD symptoms before (also @Ryan).
Now it seems obvious to me that when people are sleep deprived, that they will be less able to pay attention, that they will tend to be less inhibited (thus more impulsive), may get bored faster, which might make paying attention even more difficult etc.
The link was more obvious to me for depression. Take a look at it’s DSM criteria (major depressive episode) and then ask yourself how many symptoms may be due to sleep deprivation (which already is one of the symptoms in itself). Lack of concentration? Lack of energy? People will move less? They cannot enjoy their daily activities any more? (Physical pain, though not an official DSM criterion of this disorder, often correlates with it.) They will gain weight? Realizing all of this, they will feel depressed? And if this persists for a long time, they may even question their life’s worth and ask themselves whether being dead might be better?
I’m not saying that all cases can be explained like this, but it seems obvious to me. Serious life events remain the major risk factor. Not in all people this triggers sleep deprivation. Some people actually sleep much more than normal.
Whether or not this kind of reasoning also applies to ADHD: Clinicians concede that there’s also a lot of “comorbidity” between ADHD and major depressive disorder (besides other conditions). Which, generally, undermines the distinctive validity of these categories, at least to some extent.
I agree (see also my comment regarding sleep deprivation @Steve).
My more general point would be that even if it’s BIOLOGICAL in the sense that our psychological processes are necessarily embodied, biology (just as the other sciences) simply lack the linguistic means to cover our PSYCHOLOGY.* To me this sounds like a philosophical truism – and that it’s “philosophical” doesn’t make it less true, while in my experience many in biological psychiatry don’t care about theoretical/philosophical insights and naively-positivistically keep producing data. (Recommended read: Turkheimer, 1998, Heritability and Biological Explanation, Psychol. Rev.)
The MiA editors explicitly invited me to write an essay about heritability. If they’d also be interested in my view on why psychology (and psychiatry) cannot generally be reduced to biology (or even physics), I might be able to write this on another occasion.
* Of course, this raises that question about the subject matter of PSYCHOLOGY. Even if I don’t have a final answer, I think that the quality vs. quantity distinction (e.g., our experience, consciousness, shaped by culture) or, as philosophers put it, intentionality and phenomenal content, provide a good answer for the time being. It’d also concede that the boundary between biology and psychology cannot be drawn clearly in all cases. Anyway, agreeing that organisms/individuals cannot be understood without their environment would already help a lot.
Thanks, that’s a great quote and another way to formulate my thought that “it’s not as simple as 2 + 2 = 4”. I’ve downloaded the book and will have a closer look at it and the idea of “biological relativity”.
I agree – which raises the question why such estimates, despite being biased and wrong, are made and being cited for so long in that area of research. (I guess, but cannot prove: because otherwise people with career interests in these fields would have to admit that their method won’t deliver what they promise to deliver, which is what we have been witnessing for decades.)
The law of behavioral genetics is already – I say it again – a direct quote from the linked article.
The statement about The Bell Curve can be checked in the linked source, too, a book review by a renowned professor in 1995. The argument is developed throughout the book and not in one single sentence, as some here seem to assume.
The genetic racism in the book led to a huge discussion back then, which is well documented in various online and offline sources. However, that’s totally not the point in my essay, but that misunderstandings of “heritability” were already discussed a long time ago, e.g., by that professor in the 1990s (follow the link).
Put differently, the controversy here is not whether IQs differ between blacks and whites, but whether the “heritability” concept is misleading.
P.S. If you’re interested in the discussion of genetic racism in the 1990s, you can, besides the references I quoted, best read Chapter 13 in The Bell Curve, especially the section Genetics, IQ, and Race, starting on p. 295 – and judge for yourself.
The quote about heritability is literally how Turkheimer formulated the first law of behavior genetics, e.g. in the paper referenced here. I myself prefer to publish as much open access as possible – and even don’t have access to all scientific papers I need via our university’s library.
When I looked up the paper on Google Scholar right now (just pasting the title into the search field), there appeared a link (“[PDF] sagepub.com”) on the result page that allowed me to download the article that might also work on your computer.
But regarding your interpretation of the first law: I think this shows once more how fuzzy and dangerous the heritability concept is, how easy it can lead to misunderstanding.
I’d formulate it thus: As we are also physical, biological beings with an evolutionary history, everything has a genetic basis – genes being a kind of “blue print” which controls the production of molecules that literally constitute our organs, tissue, bodies. But as gene activity is itself subject to the environment and there is causality on the higher level (e.g. organs), genes can only explain part of the variability of the organism’s phenotype and behavior.
The information about The Bell Curve can also be found in the article by Ned Block that can be accessed via the link.
I haven’t thought about the possible relationship between SLEEP DEPRIVATION and ADHD symptoms before (also @Ryan).
Now it seems obvious to me that when people are sleep deprived, that they will be less able to pay attention, that they will tend to be less inhibited (thus more impulsive), may get bored faster, which might make paying attention even more difficult etc.
The link was more obvious to me for depression. Take a look at it’s DSM criteria (major depressive episode) and then ask yourself how many symptoms may be due to sleep deprivation (which already is one of the symptoms in itself). Lack of concentration? Lack of energy? People will move less? They cannot enjoy their daily activities any more? (Physical pain, though not an official DSM criterion of this disorder, often correlates with it.) They will gain weight? Realizing all of this, they will feel depressed? And if this persists for a long time, they may even question their life’s worth and ask themselves whether being dead might be better?
I’m not saying that all cases can be explained like this, but it seems obvious to me. Serious life events remain the major risk factor. Not in all people this triggers sleep deprivation. Some people actually sleep much more than normal.
Whether or not this kind of reasoning also applies to ADHD: Clinicians concede that there’s also a lot of “comorbidity” between ADHD and major depressive disorder (besides other conditions). Which, generally, undermines the distinctive validity of these categories, at least to some extent.
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I agree (see also my comment regarding sleep deprivation @Steve).
My more general point would be that even if it’s BIOLOGICAL in the sense that our psychological processes are necessarily embodied, biology (just as the other sciences) simply lack the linguistic means to cover our PSYCHOLOGY.* To me this sounds like a philosophical truism – and that it’s “philosophical” doesn’t make it less true, while in my experience many in biological psychiatry don’t care about theoretical/philosophical insights and naively-positivistically keep producing data. (Recommended read: Turkheimer, 1998, Heritability and Biological Explanation, Psychol. Rev.)
The MiA editors explicitly invited me to write an essay about heritability. If they’d also be interested in my view on why psychology (and psychiatry) cannot generally be reduced to biology (or even physics), I might be able to write this on another occasion.
* Of course, this raises that question about the subject matter of PSYCHOLOGY. Even if I don’t have a final answer, I think that the quality vs. quantity distinction (e.g., our experience, consciousness, shaped by culture) or, as philosophers put it, intentionality and phenomenal content, provide a good answer for the time being. It’d also concede that the boundary between biology and psychology cannot be drawn clearly in all cases. Anyway, agreeing that organisms/individuals cannot be understood without their environment would already help a lot.
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Thanks, that’s a great quote and another way to formulate my thought that “it’s not as simple as 2 + 2 = 4”. I’ve downloaded the book and will have a closer look at it and the idea of “biological relativity”.
Report comment
I’ve added here another comment regarding these questions and suggest, again, that you do your own research if that’s a topic you find interesting: https://www.madinamerica.com/2025/05/heritability-explains-less-about-mental-disorders-than-you-think/#comment-317742
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I agree – which raises the question why such estimates, despite being biased and wrong, are made and being cited for so long in that area of research. (I guess, but cannot prove: because otherwise people with career interests in these fields would have to admit that their method won’t deliver what they promise to deliver, which is what we have been witnessing for decades.)
Report comment
The law of behavioral genetics is already – I say it again – a direct quote from the linked article.
The statement about The Bell Curve can be checked in the linked source, too, a book review by a renowned professor in 1995. The argument is developed throughout the book and not in one single sentence, as some here seem to assume.
The genetic racism in the book led to a huge discussion back then, which is well documented in various online and offline sources. However, that’s totally not the point in my essay, but that misunderstandings of “heritability” were already discussed a long time ago, e.g., by that professor in the 1990s (follow the link).
Put differently, the controversy here is not whether IQs differ between blacks and whites, but whether the “heritability” concept is misleading.
P.S. If you’re interested in the discussion of genetic racism in the 1990s, you can, besides the references I quoted, best read Chapter 13 in The Bell Curve, especially the section Genetics, IQ, and Race, starting on p. 295 – and judge for yourself.
Report comment
The quote about heritability is literally how Turkheimer formulated the first law of behavior genetics, e.g. in the paper referenced here. I myself prefer to publish as much open access as possible – and even don’t have access to all scientific papers I need via our university’s library.
When I looked up the paper on Google Scholar right now (just pasting the title into the search field), there appeared a link (“[PDF] sagepub.com”) on the result page that allowed me to download the article that might also work on your computer.
But regarding your interpretation of the first law: I think this shows once more how fuzzy and dangerous the heritability concept is, how easy it can lead to misunderstanding.
I’d formulate it thus: As we are also physical, biological beings with an evolutionary history, everything has a genetic basis – genes being a kind of “blue print” which controls the production of molecules that literally constitute our organs, tissue, bodies. But as gene activity is itself subject to the environment and there is causality on the higher level (e.g. organs), genes can only explain part of the variability of the organism’s phenotype and behavior.
The information about The Bell Curve can also be found in the article by Ned Block that can be accessed via the link.
Report comment