Dear Professor Nesse, what is your opinion regarding obesity as an adaptive mechanism to an obesogenic environment with a high supply of high-calorie and highly palatable foods? Those who cannot form fat would not be able to survive in that environment.
I recently read your book Good Reasons for Bad Feelings and it opened up a new way of looking at the causes of my behavior and that of others. I quoted your book in the post below. about meeting my wife. Jealousy definitely fueled our relationship.
> For instance, it has been repeatedly suggested that tendencies to ADHD gave selective advantages in the past, but individuals in ancestral environments who had lower-than-average ability to focus attention would be expected to have lower than average fitness in ancestral environments; the disadvantages are magnified in modern environments.
Setting aside the subjectivity and broadness of ADHD diagnostic criteria, I think the most compelling argument in favor of the evolutionary advantageousness of ADHD-related personality traits (and the broad variation of human personality traits in general) is that humans evolved in groups, and that human groups are more successful when they are made up of individuals who are diverse along these dimensions. I think that Peter Gray makes this argument very convincingly [here](https://petergray.substack.com/p/follow-up-to-letters-on-adhd). I would also argue (as Peter Gray does) that diversity of personality traits is still extremely beneficial to modern human groups, but is often viewed as being less so because of the overly rigid and coercive nature of modern schooling, which is often not representative of modern work. This does not mean that there is no degree of "distractibility" or similar that is so extreme as to be deleterious overall, but taken together does, I think, mean that we should approach the question of where that line is with great humility.
I see your point (and being a non-expert, I would question myself if I didn't)
But if I understand correctly, you concede that part of the reason why many diseases haven't been selected against is (1) they bring some small advantages, or (2) they would have brought less harm in ancestral environments than they do now
Isn't there only a difference of degree between your position ("small positive selection, small negative selection") and VDAA ("important positive selection, negligible negative selection")?
If so, I understand why you would consider this line of thinking as overrated and unsubtle, but not why you would deny it categorically, as you seem to be doing
Yes, good point. And I should have given greater emphasis to diseases that are not selected against because they don’t harm fitness because their effects are late in live. But are there any diseases or disorders that themselves give a net fitness advantage? I have argued previously that too-fast male orgasm is a candidate for a trait that increases fitness at a cost to the individual and his partners but that idea may still be premature!
Surely if we could point to a specific characteristic that unambiguously improves fitness both in ancestral and modern environments we would hesitate to call it a disease
Also premature ejaculation may decrease fitness by affecting pair bonds?
I guess part of my point was, can we define "net advantage" precisely? Is there a clear counterfactual?
Like, what's the alternative to "premature ejaculation and always ejaculating"? Is it "no premature ejaculation and always ejaculating", or "no premature ejaculation and sometimes failing to ejaculate"?
It tried to think of other examples of unclear tradeoffs, including sickle cell-malaria and your long-legged-horse analogy, but I got lost in the nuance, this is tricky stuff
Dear Professor Nesse, what is your opinion regarding obesity as an adaptive mechanism to an obesogenic environment with a high supply of high-calorie and highly palatable foods? Those who cannot form fat would not be able to survive in that environment.
Thank you very much.
I recently read your book Good Reasons for Bad Feelings and it opened up a new way of looking at the causes of my behavior and that of others. I quoted your book in the post below. about meeting my wife. Jealousy definitely fueled our relationship.
https://robertsdavidn.substack.com/p/you-had-me-at-a-glance-cf9
I'm so glad you're on Substack.
> For instance, it has been repeatedly suggested that tendencies to ADHD gave selective advantages in the past, but individuals in ancestral environments who had lower-than-average ability to focus attention would be expected to have lower than average fitness in ancestral environments; the disadvantages are magnified in modern environments.
Setting aside the subjectivity and broadness of ADHD diagnostic criteria, I think the most compelling argument in favor of the evolutionary advantageousness of ADHD-related personality traits (and the broad variation of human personality traits in general) is that humans evolved in groups, and that human groups are more successful when they are made up of individuals who are diverse along these dimensions. I think that Peter Gray makes this argument very convincingly [here](https://petergray.substack.com/p/follow-up-to-letters-on-adhd). I would also argue (as Peter Gray does) that diversity of personality traits is still extremely beneficial to modern human groups, but is often viewed as being less so because of the overly rigid and coercive nature of modern schooling, which is often not representative of modern work. This does not mean that there is no degree of "distractibility" or similar that is so extreme as to be deleterious overall, but taken together does, I think, mean that we should approach the question of where that line is with great humility.
I see your point (and being a non-expert, I would question myself if I didn't)
But if I understand correctly, you concede that part of the reason why many diseases haven't been selected against is (1) they bring some small advantages, or (2) they would have brought less harm in ancestral environments than they do now
Isn't there only a difference of degree between your position ("small positive selection, small negative selection") and VDAA ("important positive selection, negligible negative selection")?
If so, I understand why you would consider this line of thinking as overrated and unsubtle, but not why you would deny it categorically, as you seem to be doing
Yes, good point. And I should have given greater emphasis to diseases that are not selected against because they don’t harm fitness because their effects are late in live. But are there any diseases or disorders that themselves give a net fitness advantage? I have argued previously that too-fast male orgasm is a candidate for a trait that increases fitness at a cost to the individual and his partners but that idea may still be premature!
Hmm
Surely if we could point to a specific characteristic that unambiguously improves fitness both in ancestral and modern environments we would hesitate to call it a disease
Also premature ejaculation may decrease fitness by affecting pair bonds?
I guess part of my point was, can we define "net advantage" precisely? Is there a clear counterfactual?
Like, what's the alternative to "premature ejaculation and always ejaculating"? Is it "no premature ejaculation and always ejaculating", or "no premature ejaculation and sometimes failing to ejaculate"?
It tried to think of other examples of unclear tradeoffs, including sickle cell-malaria and your long-legged-horse analogy, but I got lost in the nuance, this is tricky stuff