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There's a paper out in PNAS that features a number of evolutionary psychology speculations about SARS-CoV-2. Some of my friends are coauthors, so I apologize in advance to them, but I don't like parts of the paper, and I want to briefly explain why. https://www.pnas.org/content/early/2020/10/21/2009787117
The first "insight" offered is that the virus may be manipulating its human hosts by influencing social behavior during periods of infectiousness.
This is almost certainly a bat virus. Beyond D614G, there is minimal evidence of adaptation since this virus entered the humans.
This is almost certainly a bat virus. Beyond D614G, there is minimal evidence of adaptation since this virus entered the humans.
The claim is that this virus may be (1) reducing feelings of illness during transmissibility or (2) engendering mood disorders.
But it's a bat virus. That hasn't evolved substantially sincee entering humans. How precisely has it managed to do these things?
But it's a bat virus. That hasn't evolved substantially sincee entering humans. How precisely has it managed to do these things?
Maybe it does the same thing in bats. They're social too, after all.
Maybe.
But the context of the bat immune system is so different from that of the human immune system that I'm skeptical.
@caraebrook's work provides some useful background. https://elifesciences.org/articles/48401
Maybe.
But the context of the bat immune system is so different from that of the human immune system that I'm skeptical.
@caraebrook's work provides some useful background. https://elifesciences.org/articles/48401
The authors acknowledge, at least, that there is no actual *evidence* for this first insight.
In short, there is no evidence that the virus influences human social behavior, and there's substantive evidence that it *hasn't* evolved appreciable since entering the human population. As such, the adaptationist argument in this section seems premature at best.
The authors go on to suggest that understanding these issues will help us shape the evolutionary trajectory of the virus to our benefit.
How? This is a huge claim to make with no further explanation.
And (save for driving to extinction), have we done that for any other virus?
How? This is a huge claim to make with no further explanation.
And (save for driving to extinction), have we done that for any other virus?
Before I continue, I want to stress something for my non-scientist followers. These authors are experts in their fields. They are not crackpots, frauds, or anything of the sort. I've coauthored with some of them. I'm not questioning their competence.
But I do disagree with some of the claims and speculations here.
In other words, this is a scientific disagreement, and I'm not going to pull punches.
In other words, this is a scientific disagreement, and I'm not going to pull punches.
The second insight that the paper offers is at least as speculative, and almost certainly more harmful in the hands of those who want to justify the go-for-herd-immunity arguments that are currently in favor in White House circles.
The idea is that by keeping our kids at home, we are denying opportunities to be exposed to viruses that may somehow be important for brain development. As far as I know, the science is very far from settled on this. The reference list is short and not particularly authoritative.
To my surprise, discussion of more mainstream issues—the hygiene hypothesis and the old friends hypothesis—is entirely lacking. http://www.grahamrook.net/OldFriends/oldfriends.html
We're left with the conjecture that reduced social interaction is reducing virus exposure enough to cause problems that we don't really know would be caused by complete elimination of viral exposure in the first place.
And the authors are *optimistic* about adolescent behavior:
And the authors are *optimistic* about adolescent behavior:
Not only does the evidence cited here come from work in germ-free mice, not humans; we are given no evidence that reduced social activity will deprive humans of their normal biota.
In the end, this second point might be reasonable to bring up during a nothing-too-out-there brainstorming session, but to call it an insight from evolutionary biology and drop it into a heated national conversation about pandemic control strikes me as irresponsible.
I don't have too much to say about the evolutionary biology behind the third insight, the role of disgust. It seems reasonable to me that there's an evolutionary component to the capacity for disgust, and presymptomatic transmission would sidestep that avoidance mechanism.
That said, the authors seem to veer dangerously close to advocating for a program of stigmatizing disease carriers.
I assume I'm misreading this, and that after the travesty of our victim-blaming response to HIV/AIDS, public health professionals would be loathe to suggest such.
I assume I'm misreading this, and that after the travesty of our victim-blaming response to HIV/AIDS, public health professionals would be loathe to suggest such.
The section on changes in sexual behavior never gets off the ground. It seems to have learned nothing from the HIV/AIDS crisis, offers no empirical evidence about the effects of COVID on this domain, and cites nothing but a few David Buss pieces on life history theory.
"...some nations already on the cusp of population replacement level will fall dangerously below it as people opt to avoid bringing a baby into a virus-plagued world."
Claims like this one are desperately in need of supporting evidence.
Claims like this one are desperately in need of supporting evidence.
The fifth insight involves the increasing gender inequity that is resulting from the pandemic. The observations that are made in the first two paragraphs, including the ones about academia, seem spot-on.
That said, I am skeptical of claims that these patterns result from sex-specific adaptations. While one can arrive at these predictions from "evolutionary reasoning", one can reach the same by applying economic reasoning to consider how agents respond to existing gender inequity.
It's hard to find fault with insight 6, provided that "people might be nicer during in a pandemic, but they might not" can be called an insight at all.
I couldn't find the evolutionary reasoning anywhere in this section, for better or for worse.
I couldn't find the evolutionary reasoning anywhere in this section, for better or for worse.
I'm largely sympathetic to insight 7. Humans poorly internalize systemic risk, particularly on scales larger than we have historically faced. Perhaps this has an evolutionary explanation—I'm agnostic about that—but the consequences merit serious consideration.
This section also hints at the epistemic challenges we are facing in a highly interconnected world. Indeed there is a likely a profound mismatch between our current information environment and the ones we evolved to inhabit.
This deserves careful consideration as well. Moreover, I think it's worth thinking about how tech platforms are hijacking our evolved psychology to maximize our engagement rather than any more socially desirable outcome such as veracity or relevance.
While the word "requires" is strong, I likewise find little to object to in Insight 8.
The key idea here is that people are trying to different approaches to dealing with the virus in different places, and this generates the conditions for selection on cultural practices.
The key idea here is that people are trying to different approaches to dealing with the virus in different places, and this generates the conditions for selection on cultural practices.
I think we're seeing something like this on a small scale with college reopenings in the US. We have variation, we have differential success. Now let's hope for heritability: that schools that failed in August will copy the success stories in January.
Insight 9 applies author Michele Gelfand's notion of loose vs. tight cultures to varied pandemic responses around the globe. The overall theory is a bit heavy on the ecological determinism for my taste, but it's just that—a matter of taste.
Insight 10 begins with a falsehood....
...and transitions immediately to a straw man.
He is then fleshed out, though mercifully not in book-length form this time.
We meet the grim entropic reaper....
....and learn that the immune system is a product of natural selection.
And are left with a scientific agenda.
Imagine putting this as Principal Aim 1 on your next R01.
Imagine putting this as Principal Aim 1 on your next R01.
Writing by committee is hard, and the present paper seems to have largely avoided the challenges by pasting together ten short opinion pieces.
The authors—wisely, in my opinion—are unwilling to take collective responsibility for the totality of the manuscript.
I worry, however, that this point will be lost on those who find it expedient to promote individual insights from the piece.
I worry, however, that this point will be lost on those who find it expedient to promote individual insights from the piece.
All in all, the paper is an amalgam of interesting claims that are unsubstantiated and uninteresting claims that are little more than platitudes—with occasional bursts of insight hidden away here and there like a magpie's treasure.
I'm not much troubled by the platitudes. What else would one expect of a contributed perspective in PNAS? I certainly never would have written a long thread to complain about points 6 and 8-10. Besides, I'd be a hypocrite to condemn such too harshly. (Check PNAS early next year.)
I am troubled by the unsubstantiated speculation that will likely be misused to advance a libertarian agenda and set back our efforts at pandemic control.
Scientific speculation has societal impact, particularly during a pandemic. Hence the time invested in this thread.
/fin
Scientific speculation has societal impact, particularly during a pandemic. Hence the time invested in this thread.
/fin
Addendum: Lead author @Benjamin_Seitz replied to my thread with some comments of his own. Thank you, Benjamin.
I'd encourage everyone who read my words to read his response with an open mind. https://twitter.com/benjamin_seitz/status/1319514907021209601
I'd encourage everyone who read my words to read his response with an open mind. https://twitter.com/benjamin_seitz/status/1319514907021209601
Further addendum: Please read this response from author @AthenaAktipis, particularly about insight 1.
(Also, if I've missed responses from other authors, apologies—my mentions are a nightmare. Please DM me and I'll post links here.) https://twitter.com/AthenaAktipis/status/1319781063028211713
(Also, if I've missed responses from other authors, apologies—my mentions are a nightmare. Please DM me and I'll post links here.) https://twitter.com/AthenaAktipis/status/1319781063028211713
