David Barash is a professor of psychology at the University of Washington at Seattle, and has written many articles on evolution as well as several “trade” (i.e., popular) books on science for the public. In yesterday’s Wall Street Journal (link here, but you’ll hit a paywall), he’s reviewed two books on altruism in a piece called “Genes are selfish; humans are not.”
The first book he takes up is David Sloan Wilson’s new volume, Does Altruism Exist? Culture, Genes, and the Welfare of Others, published by Yale University Press. I haven’t read it, but the Amazon blurb suggests that Wilson is still banging on, as he has for years—nay decades—about his theory that altruism in humans and other species evolved by group selection. This is from the Amazon description:
From an evolutionary viewpoint, Wilson argues, altruism is inextricably linked to the functional organization of groups. “Groups that work” undeniably exist in nature and human society, although special conditions are required for their evolution. Humans are one of the most groupish species on earth, in some ways comparable to social insect colonies and multi-cellular organisms. The case that altruism evolves in all social species is surprisingly simple to make.
And it did not escape my notice, nor will it yours if you go to the Amazon page and inspect the acknowledgments, that Wilson was funded by, and vigorously osculates the rump of, the John Templeton Foundation, which for years has funded him and his program at the State University of New York at Binghamton:
For Wilson, the issue is settled: group selection explains altruism, religion, and all sorts of traits in humans and other species. If you don’t recall his claim, it’s that animal altruism is genetically based, and evolved through group selection: although altruistic individuals may suffer a reproductive deficit, sacrificing their lives or offspring to help individuals who are unrelated, groups of altruists do better than groups of selfish individuals, and hence displace them. Assuming that humans lived for much of our evolution in such competing groups, Wilson concludes that human altruism is a product of group selection.
The problems with this group-selection explanation are well known, and I’ve written about them a length. Rather than reprise them here, I refer you to Steve Pinker’s superb Edge essay on the question, “The false allure of group selection.” My own view, which I lay out in FvF, is that true altruism (in which one sacrifices one’s reproduction and/or life for unrelated individuals) is a rare phenomenon in humans, and, when present (viz., volunteer firemen and soldiers falling on grenades) is explained by either cultural phenomena (“the expanding circle” of Peter Singer) or the hijacking of behaviors that evolved by kin selection, in which one can evolve seemingly “altruistic” behaviors through natural selection, but in which those behaviors actually promote the spread of the genes producing the behavior. In a genetic sense, that’s not “altruism” at all. Group selection is a cumbersome add-on, and, as Pinker shows, there are formidable objections to that process as an explanation of altruism. Indeed, I can think of only one or two examples from nature (neither in humans) that point to group selection in any species.
But despite these problems, Wilson makes the best of a bad position, simply sounding an unseemly and scientifically unwarranted note of triumphalism in posts on his website such as “Mopping up final opposition to group selection,” and “The tide of opinion on group selection has turned.” Barash rejects the cry of victory:
. . . the best scientific explanation for altruism’s existence (and the one accepted by most evolutionary biologists) is that, at the most basic causative level, altruism isn’t really altruism at all, but rather selfishness. When bodies appear to be acting altruistically, what’s actually happening is that “selfish” genes within those seeming altruists are benefiting identical copies of themselves in other bodies, often genetic relatives. Other mechanisms have also been identified, including reciprocity, manipulation, reputation enhancement and, at least in theory, group benefit: Some have proposed, that the herd or colony (or as we might say, community) is the unit of natural selection, rather than the individual organism.
This last possibility, although accepted at times in the past, has been largely debunked, with the recognition that, in fact, genes are the entities that reproduce themselves and that persist over time. Moreover, altruism is necessarily overwhelmed by selfishness within a group. In order for natural selection to promote altruism, groups containing altruists would have to reproduce themselves so effectively as to outweigh the selection against altruism among the group’s individuals. It’s a mighty tall order.
David Sloan Wilson, a professor of anthropology and behavioral sciences at Binghamton University, has nonetheless been a persistent advocate for group selection, and “Does Altruism Exist?” is the latest salvo in his rather lonely campaign. Indeed, many evolutionary biologists can hardly believe that such an accomplished researcher can be so stubbornly persistent in a losing cause. “When smart people take a wrong turn at the beginning,” he writes at one point, “they often go a long way before realizing their mistake.” Indeed.
Note that, according to Barash, Wilson makes a pretty serious mistake in imputing multicellularity to group selection (my emphasis):
Many animals live in social groups and tailor their behavior to maximize their success and that of their relatives within those groups. But it is misleading to describe such individual-level adaptations as having evolved “for the benefit of the group.” Especially absurd is Mr. Wilson’s contention that the very existence of multicellular organisms, including human beings, supports his contention; he claims that each of us is a group whose cells might therefore be congratulated for their coordination and cohesion, as a manifestation of group-selected altruism. The simple reality, however, is that our cells are genetically identical. When a liver cell labors at the unpleasant task of detoxifying blood while leaving all the fun of reproducing to the gonads, that cell isn’t being altruistic at all but rather wholly selfish, since the success of the gonads is biologically indistinguishable from success of the liver cell.
“Does Altruism Exist?” presents a simple arithmetic model purporting to show how altruism can readily evolve by group selection. It does nothing of the kind. The model is based on some simple assumptions, including the rather large one that groups containing altruists are more fit than groups whose members are all selfish. From there, it is easy to see that group selection “works” and that altruism can win out over selfishness, even though individual altruists are less fit than their selfish colleagues. I could similarly demonstrate my ability to outrun Olympic gold medal sprinter Usain Bolt: Start with the assumption that I run 100 meters in 8.9 seconds; the rest is easy.
Barash then says that humans might indeed be a species in which group selection is theoretically possible, because we can punish defectors and, at least at present, feel that we should act for the benefit of the group. But Barash doesn’t mention that those feelings can be more parsimoniously explained by either reciprocal altruism or kin selection, as invoking group selection means a relentless pruning of entire groups, which then become unstable to the invasion of “selfish” genes. Altruistic groups are simply unstable to the invasion of non-altruists. (The turnover of entire groups must outpace the turnover of gene copies, an unrealistic assumption.) And, as Pinker points out, the qualities that have enabled societies to thrive are not sweetness, light, and empathy, but coercion, brutality, and oppression:
Thus we have a nice set of competing empirical predictions for any examples of group-benefiting self-sacrifice we do observe in humans. If humans were selected to benefit their groups at the expense of themselves, then self-sacrificial acts should be deliberate, spontaneous, and uncompensated, just like other adaptations such as libido, a sweet tooth, or parental love. But if humans were selected to benefit themselves and their kin in the context of group living (perhaps, but not necessarily, by also benefiting their groups), then any guaranteed self-sacrifice should be a product of manipulation by others, such as enslavement, conscription, external incentives, or psychological manipulation. [Pinker then shows that the latter hypothesis better fits the facts.]
. . . Finally, let’s turn to the role of altruism in the history of group-against-group conflict. Many group selectionists assume that human armed conflict has been a crucible for the evolution of self-sacrifice, like those in insect soldier castes. They write as if suicide missions, kamikaze attacks, charges into the jaws of death, and other kinds of voluntary martyrdom have long been the norm in human conflict. My reading of the history of organized violence is that this is very far from the case.
. . . The historical importance of compensation, coercion, and indoctrination in group-against-group competition should not come as a surprise, because the very idea that group combat selects for individual altruism deserves a closer look. Wilson’s dictum that groups of altruistic individuals beat groups of selfish individuals is true only if one classifies slaves, serfs, conscripts, and mercenaries as “altruistic.” It’s more accurate to say that groups of individuals that are organized beat groups of selfish individuals. And effective organization for group conflict is more likely to consist of more powerful individuals incentivizing and manipulating the rest of their groups than of spontaneous individual self-sacrifice.
I’d highly recommend that you read Pinker’s essay in toto if you want a good presentation of why group selection is an unrealistic explanation for cooperative behaviors. It’s accessible to the scientifically interested layperson.
Barash concludes that D. S. Wilson’s declaration of victory is completely unwarranted:
Mr. Wilson deserves a kind of admiration for his lonely battle to resuscitate group selection, even perhaps for his chutzpah, as when he claims that “multilevel selection” (which includes group selection) is “in the same category as other scientific advances, such as the Copernican view of the solar system, Darwin’s theory of evolution, and the theory of continental drift.” Nearly as bizarre is his claim that group selection has “won” the scientific battle, which brings to mind the suggestion by Sen. George Aiken, during the Vietnam War, that the United States ought to declare victory, unilaterally, and then leave. At least in that case the U.S. really had won every major battle. Mr. Wilson is of course free to declare his own victory, but his “forces” haven’t achieved anything of the sort.
I don’t think that “admiration” is the appropriate feeling here; “pity” is more apposite, or even distaste at the hubris of comparing multilevel selection to the ideas of Darwin and Copernicus. In my view, Wilson is wasting a perfectly good brain peddling a dubious scientific product, and, to make matters worse, then distorts the situation by falsely claiming that the battle is over: he’s won big time. But he hasn’t, for virtually everyone who works on the evolution of social behavior has rejected the hegemony of group selection. Why that makes Wilson declare victory even more vociferously is a matter for psychologists.
The other book that Barash reviews is a huge tome that deals not with the biology of altruism, but its various social aspects, as well as an attempt to promote it. It’s the 864-page behemoth Altruism: The Power of Compassion to Change Yourself and the World by Matthieu Ricard, a Buddhist monk. Since it doesn’t deal with biology, I’ll pass over it except to say that Barash, who has himself written approvingly of Buddhism, likes it a lot:
But whereas Mr. Wilson is interested in altruism in part because it serves his purpose — making a case for a scientifically dubious phenomenon (group selection) — Mr. Ricard is simply concerned with altruism for its own sake: He wishes to explore and promote it by whatever means necessary and regardless of the mechanism(s) by which it may be furthered.
. . . A personal confession: When I agreed to review this enormous book, I had the sneaky, selfish temptation to simply skim it (after all, I already knew a fair amount about the biology of altruism and about Buddhism). But I was waylaid by Mr. Ricard’s erudition, his captivating prose, the depth and the breadth of his material. This book is so rich, so diverse and, yes, so long that it is best kept as an inspiring resource to be consulted over many years.
Reblogged this on ShereeKrider.
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I always wonder if acts like jumping on hand grenades are a maladaptive fear/flight reflex response; an amygdala hijacking – a visceral attempt to control an uncontrollable situation. I have no creds to make such a statement, just something I try to make sense of however.
Like watching my (ex)wife try and stop a coasting chainsaw blade with her bare hand (not a good outcome); doesn’t make sense.
Maybe. But there are plenty of other cases of soldiers repeatedly exposing themselves to enemy gunfire to save wounded comrades. Some even do this repeatedly, and one would think that they had some time to think a bit first before just reacting instinctively.
The better explanation is that it is an appendage of kin altruism. The extremely strong bond between close family members has been supplanted by the extremely strong bond between soldiers in combat.
In Pinker’s book The Better Angles of our Nature he writes extensively (and convincingly) about altruism among soldiers as an appendage of kin altruism.
Actually, I meant ‘kin selection‘, but it worked anyway, I see.
I don’t think we should overlook the role learning plays in such acts. Soldiers receive a great deal of rigorous training designed to foster unit loyalty and to stress the primacy of mission success over any individual interests.
One might even say, brainwashing.
Hi Andrikzen,
A Royal Marine named Matt Croucher did lay on a hand grenade and won himself the George Cross. He relates his experience in a book Bullet Proof. He survived I assume you have guessed. He threw a knapsack onto the grenade and laid on the grenade curling into a ball. The grenade went off, Matt was able to get up and continue the patrol.
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On the subject of books, just to report that I am now the proud owner of a copy of WEIT, personally signed by Professor CC with added cat, thanks to PCC’s untimely mention of a certain C. J. W*rl*m*n. Thanks Jerry!
You’re welcome, but I won’t make that mistake again!
We’ll be watching!
I’ve mentioned this before, but I think it would be fun if everyone who has a cat illustration by PCC should send a photo of it to PCC for a fun post.
Agree. 🙂
The subject of group selection always seems to be attached to “real altruism” which, as you point out, is quite rare. But what about common emotions like compassion and empathy? When I see a child from the other side of the world suffering who is clearly not related to me, my feelings of compassion and empathy and the desire to help are off the charts. I donate money even though I am in debt. I cry a little and have overwhelming feelings of unity with those who are helping. Lump in my throat type of stuffI know these feelings are not learned behavior. This compassion and empathy is not learned, it’s in my genes to be this way.
Is this hijacked kin selection at work? If not. What is it? Is group selection definitely off the table here? I Would love to understand this better.
The first thing to keep in mind is that most human emotions haven’t evolved in a modern world, so how we behave in a city, say, isn’t necessarily the environment in which our ancestral lineage evolved. Organized cities didn’t even first appear until around five to seven thousand years ago, and most experts agree that “modern” Homo sapiens arose more or less one or two hundred thousand years ago.
The second thing to keep in mind is that altruism in the biological sense isn’t the same as the everyday meaning of altruism as “compassionate and selfless”. A biologically meaningless charity donation today might once have been a clever genetically programmed strategy for gaining helpful allies, a good reputation, or even both.
Yes. We see similar behaviors in some animal societies, especially other primates. They can be generous with food and grooming but they expect a return. They are seen to be especially generous when they know they can be seen by others in their groups.
They seem all too human, or rather, we are all too monkey. So these compassionate acts are, likely, emergent from living in small close-nit groups.
Another thing: general niceness is not actually that hard to figure out from evolutionary principles. Trivers has what I think is a well-reasoned application of reciprocal altruism and how many of our emotions correspond to different parts of the strategy. The basic point is that, so long as the genes responsible for the strategy payoff through survival and replication via reproduction, or at least aren’t harmed by them, then “selfish gene” theories don’t pose much of a challenge when it comes to explaining such behaviour.
That’s why there’s such a focus on the “rare altruism”; because a gene that commits suicide would be a big deal for the theory, so if selfish gene theory is true, then it must explain such seemingly self-defeating behaviour without compromising the selfish-gene aspect.
Huh. And to think; a few days ago, I encountered someone online who praised E.O. Wilson’s contributions to group selection and described his critics’… well, criticism… of his idea as “a tremendous amount of angry, often ideologically-motivated opposition, including attacks from Richard Lewontin, Stephen J. Gould, Richard Dawkins, and Steven Pinker”.
Seeing how Wilson and his fellow group selection advocates go about their work, especially when contrasted with Dawkins’ and Pinker’s actual criticisms, I can’t help but think it’s more the other way around.
Don’t forget all the other critics of E.O. Wilson’s (and D. S. Wilson’s) views:
Patrick Abbot, Jun Abe, John Alcock, Samuel Alizon, Joao A. C. Alpedrinha, Malte Andersson, Jean-Baptiste Andre, Minus van Baalen, Francois Balloux, Sigal Balshine, Nick Barton, Leo W. Beukeboom, Jay M. Biernaskie, Trine Bilde, Gerald Borgia, Michael Breed, Sam Brown, Redouan Bshary, Angus Buckling, Nancy T. Burley, Max N. Burton-Chellew, Michael A. Cant, Michel Chapuisat, Eric L. Charnov, Tim Clutton-Brock, Andrew Cockburn, Blaine J. Cole, Nick Colegrave, Leda Cosmides, Iain D. Couzin, Jerry A. Coyne, Scott Creel, Bernard Crespi, Robert L. Curry, Sasha R. X. Dall, Troy Day, Janis L. Dickinson, Lee Alan Dugatkin, Claire El Mouden, Stephen T. Emlen, Jay Evans, Regis Ferriere, Jeremy Field, Susanne Foitzik, Kevin Foster, William A. Foster, Charles W. Fox, Juergen Gadau, Sylvain Gandon, Andy Gardner, Michael G. Gardner, Thomas Getty, Michael A. D. Goodisman, Alan Grafen, Rick Grosberg, Christina M. Grozinger, Pierre-Henri Gouyon, Darryl Gwynne, Paul H. Harvey, Ben J. Hatchwell, Jürgen Heinze, Heikki Helantera, Ken R. Helms, Kim Hill, Natalie Jiricny, Rufus A. Johnstone, Alex Kacelnik, E. Toby Kiers, Hanna Kokko, Jan Komdeur, Judith Korb, Daniel Kronauer, Rolf Kümmerli, Laurent Lehmann, Timothy A. Linksvayer, Sébastien Lion, Bruce Lyon, James A. R. Marshall, Richard McElreath, Yannis Michalakis, Richard E. Michod, Douglas Mock, Thibaud Monnin, Robert Montgomerie, Allen J. Moore, Ulrich G. Mueller, Ronald Noë, Samir Okasha, Pekka Pamilo, Geoff A. Parker, Jes S. Pedersen, Ido Pen, David Pfennig, David C. Queller, Daniel J. Rankin, Sarah E. Reece, Hudson K. Reeve, Max Reuter, Gilbert Roberts, Simon K. A. Robson, Denis Roze, Francois Rousset, Olav Rueppell, Joel L. Sachs, Lorenzo Santorelli, Paul Schmid-Hempel, Michael P. Schwarz, Tom Scott-Phillips, Janet Shellmann-Sherman, Paul W. Sherman, David M. Shuker, Jeff Smith, Joseph C. Spagna, Beverly Strassmann, Andrew V. Suarez, Liselotte Sundström, Michael Taborsky, Peter Taylor, Graham Thompson, John Tooby, Neil D. Tsutsui, Kazuki Tsuji, Stefano Turillazzi, Francisco Úbeda, Edward L. Vargo, Bernard Voelkl, Tom Wenseleers, Stuart A. West, Mary Jane West-Eberhard, David F. Westneat, Diane C. Wiernasz, Geoff Wild, Richard Wrangham, Andrew J. Young, David W. Zeh, Jeanne A. Zeh & Andrew Zink
Not an expert here, but as I recall it, the disagreement Gould and Lewontin had with E.O. Wilson concerned not group selection, but evolutionary psychology (or “sociobiology” as Wilson termed it; the “selectionist agenda” in Gould’s words). On this issue, Dawkins and Pinker (and Dennett, too) lined up on the same side as Wilson.
Yes, you’re right. I’ll say this for Wilson: it was appalling the way he was treated as a result of publishing his work on Sociobiology. Now they were some NASTY ideologically-motivated attacks, they were.
Right you are, though I sometimes wonder if Wilson didn’t engender professional resentment with his presumptuous use of the definite article in the subtitle of his Sociobiology book, the post-colonic “The New Synthesis” rather than simply “A New Synthesis.”
I think altruism is a product of civilization, the opposite of selfishness also the result of ownership. In nature there is only fair play. Whether within species or across predator-prey, it is give-and-take. If one member or one group take more than they contribute, it is a losing game in the long run.
“In nature there is only fair play”? Only if you have an idiosyncratic definition of “fair play,” one that comprises devouring the young and abandoning the sick and old.
Nature is red in tooth & claw. The hunt isn’t conducted according to marquess of queensberry rules, and apex predators aren’t big on noblesse oblige.
In the jungles of Wall Street, Madison Avenue, and silk-stocking Park Avenue law firms — where professional life can be “nasty, brutish, and short” — it’s called “eat what you kill.”
One thing I’m wondering about…where and how does one draw the line between kin and group?
We are, after all, all cousins — even the ferns and the jellyfish. But Erik, my mother’s brother’s son, is much more closely related to me than a fern, and my (half) sister Nadine (shared mother). is even more closely related to me than Erik.
I’m assuming Nadine is my kin, for the purposes of this discussion. Is Erik? How about Damien, who’s Nadine’s brother by a different mother and father from mine?
Or how about somebody picked at random? If I remember right, no two living humans are more distantly related than about 30th cousins, with the global average much closer than that, and the regional (~100 mile radius) average much closer still.
…or, of course, Baihu, with whom I share an ancestor only about a mere hundred million years or so ago, give or take….
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I think you misunderstand the logic behind kin selection. It’s not genealogical connections that are important, per se. It’s the probability that an allele can find and help/be helped by a copy of itself in another body, and so the odds that such behaviour will pay off versus the odds of the allele taking itself out. Basically, instead of looking at the family tree for yourself, look at the gene probabilities as if you were a selfish allele trying to gain immortality through your copies.
Given the way sexual reproduction works, the gamble quickly becomes suicide after only a few degrees of relatedness, which is why you’re not likely to throw yourself in front of a bus for the sake of a fern thicket.
Probably someone has made my point further down already, but rather than “look at the gene probabilities as if you were a selfish allele trying to gain immortality through your copies” it would be better to specify “a selfish allele that only appeared by mutation in the last few generations“; that’s why the high average relatedness to random conspecifics doesn’t have much more relevance than relatedness to other species.
Oh, apparently nobody else made the same point. As far as I understand, the recent origin of the hypothetical mutant allele greatly simplifies the derivation of Hamilton’s Rule, but (for non-obvious reasons) is not a necessary assumption for its validity.
You have to draw the line at the species level, and the species has to be sexually reproducing. You can think of a particular trait as competing with all alternative traits to dominate its particular gene pool. In this case, either helping yourself or helping identical copies in others has the same effect – increasing your representation in an inter-connected pool. This is why we (humans) aren’t more fond of chimps than say, cats. Even though we share more identical DNA. Helping a gene in a chimp population does nothing to increase that gene’s frequency in the human population. This is also why kin selection does not apply to asexual clones (although it often is wrongly assumed to because of 100% shared genetic identity). However, such organisms are forever more reproductively isolated into a gene pool of one the moment they are arise and therefore should show no more altruism to each other than we do to chimps. If cooperation does evolve in these situations it has to through mutualistic benefit. And it is better understood as a group-selected process rather than a kin-selected one. This is why some argue that multicellularity is an example of group selection. It has to be if the first multicellular organism was also asexual.
Traits don’t compete with other traits, though. Alleles compete with other alleles via the traits they promote and influence, and the competition is always fiercest where animals have almost identical ecological niches, which would almost certainly be the case among asexual relatives with different alleles.
That’s why you’re incorrect to claim that asexual clones have no special ties to each other, and therefore are exempt from Hamilton’s rule. It’s true that, once an allele arises, its host’s descendants are going to carry it no matter what. Yet, an asexual species is still going to have competition over the resources for survival (and thus reproduction). In such contests, a tendency for an allele to help its descendants – who are going to carry it as a copy – could lend a huge survival advantage, and thus enable its spread. Hamilton’s rule at no point restricts itself to a sexually reproducing population. It only cares about the probability that a copy is in the recipient’s body, and the cost:benefit ratio of the recipient versus the donor.
Lastly, mutualistic benefit doesn’t need group selection. There are, in any case, much better theories for the origin of multicellularity. Here are some examples:
https://en.wikipedia.org/wiki/Multicellular_organism#Hypotheses_for_origin
I hasten to add that the competition here occurs within the species, not between different species. The competition is over food, other resources, and places in the next generation of the species in the environment.
No, your argument is one that is called a greenbeard – identical alleles ought to help each other. In that case, humans should help chimps with the same eye color over other humans with a different eye color. Greenbeards can work but also only within species (and to very limited extent). From a selection perspective, clone lines will rapidly diverge from each other by mutation. Your argument is that there is something special about the initial 100% similarity in clones versus 98.9% genetic similarity between humans and chimps, despite both evolving as separate “species”. One has to be consistent in either saying kin selection applies both within and across species and reproductive isolation does not matter. Or that it only applies for reproductively non-isolated individuals. That rules out asexual clones.
Your argument is that there is something special about the initial 100% similarity in clones versus 98.9% genetic similarity between humans and chimps, despite both evolving as separate “species”.
What? That’s not even remotely anything like my argument.
For one thing, that 100% vs 98.9% bit shows you can’t tell the difference between “probability of containing a copy of the allele” and “amount of total identical genetic material”. That’s a kindergartener error!
If it helps to keep them straight, remember that the allele is a mutant starting off in one founder body, and has to get from there to population fixation in a competitive environment surrounded by rival mutants of different alleles.
Seriously, confusing something like “your sibling has a 50% chance of carrying your gene(s)” with “chimps and humans share 98% of their DNA” is a huge error! You think a mutated allele in an archaean bacterium is ever going to care about what’s going on in the gene pool of a species it’s not even ecologically competing with?
I didn’t say “identical alleles ought to help each other”. My point was that, if an allele arises that, say, takes care of its descendants in an asexual population, then it can help itself to outcompete variants that don’t have that allele, meaning better survival (and therefore reproductive) chances. For instance, it might willingly take risks to increase the survival odds of its descendants, who in turn will make the same risks for their descendants, giving them a competitive advantage against near-identical species members who nevertheless don’t make such sacrifices.
Think about it. An asexually reproducing species might not mix genes reproductively, but they’re still fiercely competing for space and resources in a Malthusian battle for survival, if only because on that one slot where two different alleles have arisen and one is better at reproducing or surviving than the other. That’s all it needs. A mutant strain that can push back or even overwhelm the competing populations and thus fixate is going to, and kin selection offers one strategic avenue.
Sorry, that should’ve been “archaean OR bacterium”.
You were actually correct in your previous correction about operating within species. Although we can define “species” in many different ways, most are for helping us to organize our thinking about nature. The one that matters for evolution is based on whether or not reproductive isolation exists. By this definition every asexual individual must functionally be its own species. Until you can show why reproductive isolation does not matter, then it is your argument making the mistake of proportional comparisons (i.e., you are saying that 100% is somehow different from 98%). Competing for space is true – but you are now evoking group selection at a species level.
My point is that an asexual species competing in a Malthusian competition is the milieu in which kin selection is supposed to operate in an asexual species. While it’s true that defining a species for asexual creatures is not as easy as doing so for a sexual population, it’s ridiculous to go to the other extreme and act like every individual is suddenly its own species. Evolution doesn’t rely on reproductive isolation. It relies on competition between alleles over loci in the next generation. Usually this is the same genetic slot in bodies within a sexually reproducing species population, but it doesn’t HAVE to be so.
Take aphids trapped in a garden. All of them are clones of an original aphid founder from several generations back, and when they invade the empty garden, they fill up the ecological niche of sap-sucker. Although a single aphid can produce many clones, obviously they can’t all survive, so the population is stable, with no particular lineage gaining an advantage. Let’s call the unrivalled allele here Version 1.
Now one of them gains a mutation – Version 2 – and this mutation means that, when it reproduces, instead of leaving its descendants to fend for themselves, it gives them a packet of sap or something to boost their strength, at the cost of weakening itself or even dying. This is the kin selection altruism bit. Now, its descendants have the allele which means proportionally more of their descendants will gain more than their rivals, meaning more survive and reproduce, increasing the proportion of carriers in the population. Soon, the garden is devoid of Version 1, and Version 2 reaches fixation in the population.
There. Kin selection in an asexual population. What’s so hard about that?
Until you can show why reproductive isolation does not matter, then it is your argument making the mistake of proportional comparisons (i.e., you are saying that 100% is somehow different from 98%).
The point is that the Malthusian limits are what restrain the genes within the species of aphids and force them into conflict with each other. When a mutated allele arises, it “wants” to reach fixation against its rival at the genetic locus that either it can replace or it can be replaced by. And since closely related individuals are the stiffest competition, there’s no worry about talking about a species even in an asexual species.
This is the milieu in which kin selection operates. It is different from the genetic calculation that is involved in kin selection. Got it?
A species removed by a lot more genetic variation is also going to be in a different ecological niche enough for competitive fitness to not be an issue. Or to put it another way: genes in aphids don’t compete against and aren’t interested in a lineage all the way over there, minding its own ecological business. I really don’t see what’s so hard to grasp about this.
Competing for space is true – but you are now evoking group selection at a species level.
The heck are you on about? I’m invoking kin selection among a population, with an allele competing for the “locii” of the bodies in the next generation in an ecological niche, guided entirely by selfish gene theory.
“Now one of them gains a mutation – Version 2 – and this mutation means that, when it reproduces, instead of leaving its descendants to fend for themselves, it gives them a packet of sap or something to boost their strength, at the cost of weakening itself or even dying.”
What you are asking in this example is, should a parent invest more or less in an offspring it is producing? Assuming there is an “optimal” investment level, all you are demonstrating is an increase in direct reproduction and not indirect reproduction. You don’t need to invoke either kin or group selection – this is pure individual self interest. Of course the optimal trait spreads. What would not be favored is for the aphid to give the sap to a random clonemate. In your Malthusian world all the clones are competing for the same resource. What advantage would any individual have in reducing its own chances relative to another individual that is likely already differentiated through generations of mutations? It should keep the sap and reproduce itself even more. You are selecting for the best adapted clone (=species!) to the garden, with no kin selection involved.
Assuming there is an “optimal” investment level, all you are demonstrating is an increase in direct reproduction and not indirect reproduction. You don’t need to invoke either kin or group selection – this is pure individual self interest.
Dude! Parent-offspring interactions are a huge part of kin selection. Do you even know the first thing about the theory?
An individual helping its offspring is NOT doing it for “pure individual self interest”. It harms the individual’s chances, and in some cases kills it. The individual that benefits is someone else. It’s from the allele’s point of view that it’s pure self-interest, because the allele only does it when it’s in its own interests to do so. If the cost/benefit tips the other way, there won’t be any biological altruism.
And tell the difference between individual selection and gene selection!
What would not be favored is for the aphid to give the sap to a random clonemate.
For god’s sake, I never once said the theory predicted it would! A mutant allele that helps itself may or may not benefit from biologically altruistic behaviours towards other carriers. In an asexual population, an allele that arises that performs such altruism towards its descendants is fitting right into the factors that make up kin selection: high probability of the descendant carrying its allele, combined with a cost/benefit analysis for fitness.
Alleles, man. Probability of finding a copy in another carrier. NOT degree of overall genetic relatedness!
Parent-offspring relationships are direct fitness! Hamilton & kin selection are an attempt to explain why some individuals give up direct fitness to help others with their reproduction. If you simply define reproducing itself as kin selection, then of course everything is kin selection. All you have done is rediscover Darwin. Go back to your aphid example and replace Version 1 & 2 with Species 1 and 2 and you get the EXACT same outcome. No kin selection involved. Darwin could explain it for you.
Parent-offspring relationships are direct fitness!
Only in inclusive fitness. See:
https://en.wikipedia.org/wiki/Inclusive_fitness#Inclusive_fitness_and_parental_care
Inclusive fitness theory was developed in order to better understand collateral altruism, but this does not mean that it is limited to collateral altruism. It applies just as well to parental care. Which perspective one chooses does not affect the animals but just one’s understanding.
Kin selection is an explanation for biological altruism, which is concerned with reducing an individual’s fitness (survival and reproductive chances) in return for improving another’s. Let me repeat that: it is about biological altruism towards another individual, including offspring. That is not identical to any old interaction towards offspring. And it is not some midway point between “individual selection” and “group selection”. It falls naturally out of the selfish gene theory and other neodarwinian concepts.
Hamilton & kin selection are an attempt to explain why some individuals give up direct fitness to help others with their reproduction.
And survival. That’s the cost/benefit analysis in Hamilton’s rule. In this case, the explanation is that, from an allele’s point of view, it can be selfishly worth their time to make their hosts compromise individual fitness, like sacrificing a chess piece in order to aid a white or black side.
If you simply define reproducing itself as kin selection,
I don’t. The point is that, IF a copy of the allele has a certain probability of being in another animal (in this case, the descendant), AND if the benefit to the recipient outweighs the cost to the host, THEN you can get the evolution of altruism towards kin. The emphasis is on the probability that the allele is also present in that body. Hence why the aphid sacrifices its safety for the sake of its offspring, because in that particular case, the loss of the aphid parent is offset by the improved gain in the descendants. That doesn’t have to be the case; it might be that the cost/benefit analysis doesn’t favour such altruism, in which case the most successful allele will be the one that basically says “Bugger the offspring.”
Go back to your aphid example and replace Version 1 & 2 with Species 1 and 2 and you get the EXACT same outcome.
No you don’t! In the example, the ONLY difference between Version 1 and Version 2 is that the latter has an allele at, say, Locus 1287 on the genome that favours biological altruism towards offspring in accordance with Hamilton’s rule. A biologist would still class either within, say, Microchromus acephalis. Define species practically as a population of organisms that have a high level of genetic similarity, or define them phylotypically, as many researchers do when classifying asexual species. It makes no difference to the kin selection case, but it would help if you stopped getting so hung up on it.
Look, I think you really don’t grasp what kin selection actually is. I’d recommend tracking down a 30th anniversary edition of The Selfish Gene, finding the footnote to page 94, and reading the discussion on kin selection. It is not rocket science.
Appealing to one’s own credentials is kind of the lowest form of argument, but since it is obvious that one of us has no grasp of inclusive fitness, kin selection and the difference between the two (and you keep insisting it’s me!) – here’s a few of my peer-reviewed papers to consider:
How (not) to review papers on inclusive fitness. (2015) TRENDS IN ECOLOGY & EVOLUTION 30:235-237.
Kinship, parental manipulation and evolutionary origins of eusociality. (2015) PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 282:20142886.
Monogamy and high relatedness do not preferentially favor the evolution of cooperation. (2011) BMC EVOLUTIONARY BIOLOGY 11:58.
Social heterosis and the maintenance of genetic diversity. (2007) JOURNAL OF EVOLUTIONARY BIOLOGY 20:2253-2265.
Transactional skew and assured fitness return models fail to predict patterns of cooperation in wasps. (2006) AMERICAN NATURALIST 167:467-480.
Testing models of parental investment strategy and offspring size in ants. (2006) OECOLOGIA 146:667-674.
Optimal reproductive-skew models fail to predict aggression in wasps. (2004) PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES 271:811-817.
Measuring and using skew in the study of social behavior and evolution. (2000) AMERICAN NATURALIST 156:577-589.
Alloparental care and eusocial evolution. (1991) OIKOS 62:122-125.
Queen number in colonies of social hymenoptera as a kin-selected adaptation. (1988) EVOLUTION 42:566-580.
Ant reproductive strategies and sex allocation theory. (1986) QUARTERLY REVIEW OF BIOLOGY 61:1-21.
So I think there is some evidence that I kind of know what I’m talking about… when I say you’re wrong.
Indeed, we share 99.9% of genes with every other human. That’s a lot of common genes that get passed on no matter what human we help.
Then why the dearth of human altruistic self-sacrifice for our 99% cousin the chimp?
We are the 1…er, the .9 percent?
I care about chimps deeply. Don’t you? I suspect most people do.
Sure, Matt, I care about chimps and bonobos and all my fellow great apes, too.
But I’m not planning on sacrificing any of my own reproductive fitness for them (especially the bonobos, who always have their freak on). Are you?
Great article, Ken. Loved the dog humping the dowager’s fleshy calf…
I voluntarily discarded my reproductive fitness because my wife and I like to travel and double income no kids rocks. The bonobos can have it if they want.
The rather straightforward mathematics of kin selection led J.B.S. Haldane to say that ‘he would willingly die for two brothers or eight cousins’.
A question frequently heard in the Kentucky marriage registrar’s office.
I remain skeptical of the claim that volunteer firefighters exhibit “true” or “pure” altruism. Seems to me there’s considerable social cachet conferred on firefighters: mayors pin medals on them; photographers publish beefcake calendars of them; women want to date them; little boys want to grow up to be them. So that has to be weighed against the risk of death (which if they’re doing their job properly is fairly small).
I imagine a case could also be made that conspicuous risk-taking altruism of this sort can be construed as a kind of advertisement to potential mates: if I do this for strangers, imagine what I’ll do for our children.
Volunteer (as opposed to “true” or “pure”) firefighters? They usually have all the cachet and beefcake appeal of chubby, balding slow-pitch softball players or high-handicap golfers.
(Advance apologies to any members of the WEIT commentariat who serve as volunteer firefighters. Thanks for your dedication.)
I read with amusement the blathering about volunteer firefighters from those who apparently don’t know one. I was one for 30 years–firefighting, heavy rescue, technical rescue (high angle, confined spaces, underwater S&R), and EMS. There is precious little ‘pure’ altruism, but there are a lot of rewards. I recall coming back to the station sometime around 2:30 am, tired and dirty after a pesky chimney/attic fire. After we got the equipment cleaned up and back in service, half a dozen of us sat on folding chairs in a semicircle on folding chairs in an open truck bay, summoning the energy to get up and go home. Finally one guy, Denny G, raised his head and said with not a little sarcasm, “Remember, guys. It’s the camaraderie.”
From that very real camaraderie (see a firefighter’s funeral) to being able to drive big trucks with red lights and sirens and air horns, there’s a wide range of reinforcements for volunteer firefighters. Please stop using us as an example of ‘pure’ altruism. Truth be told, we get a helluva kick out of our avocation.
Free version of Barash essay here:
http://www.wsj.com/articles/genes-are-selfish-people-are-not-1434144343
Oops. Try clicking on this URL.
http://www.wsj.com/articles/genes-are-selfish-people-are-not-1434144343
Do I need to create an account there to read it and is that free?
The idea of altruism among cells in the embryonic development of multicellular individuals is interesting. There is a quite different idea in Leo Buss’ old book “The Evolution of Individuality”. Buss develops a compelling argument that in the first multicellular sexual organisms there was competition (not altruism) among cells to become germ cells (sperm & eggs). Some lines of cells ‘won’ that competition by evolving molecular signals that forced all other cells in the organism to become somatic (and never become sexual). Once those signalling mechanisms were well-established, it was possible for somatic cells to evolve specializations to form different tissues and organs (because what else are they going to do?). Buss argues that these signalling adaptations in the earliest multicellular organisms (to resolve conflict among cell lines) are the early evolutionary predecessors of the signalling processes that run embryonic development in present-day organisms, and turn the fertilized egg into millions of cells consisting of hundreds of different cell types. That embryonic development looks to us like a sort of harmonious, cooperative dance of dividing, moving, differentiating cells. But in reality (according to Buss) this process and the molecular signals that run it originally arose out of natural selection based on competition and conflict rather than out of selection for harmony and altruism.
I think I understand, more-or-less, the arguments against a genetic basis for group selection. However, it seems plausible and even likely to me that “true” altruism could be due to cultural evolution. Cultural norms and memes that encourage altruism must have a strong effect of the survival of cultures and the individuals within them. The family proud of their son who won the Medal of Honor gets status, just like the family proud of their son who was a suicide bomber does. The (presumably) celibate Catholic priest and his family have status within a traditional Catholic culture.
This assumes that cultural evolution is a real thing, which I think it is, and that it’s a reasonable metaphor or analogy to biological evolution, which I think it is.
Agree. It’s no accident that we celebrate our heroes–the more people who crave that “glory,” the better off we are.
A fireman of my acquaintance said that the appeal of the profession is the opportunity to smash things with a hammer or axe. He thought that all firemen felt the same way.
One that I used to know in Brooklyn was torn between his love for big machines and shiny new technology, which he could play with on Long Island, or big fires in abandoned buildings, which he could fight with older equipment in Brooklyn. He opted for the bigger fires.
I got the impression from years ago (we went to a fire station as a field trip when I was in kindergarten, IIRC) that the fire pole was part of it too 😉
If, as Barash says, the apposite quote regarding D.S. Wilson’s group-selection strategy comes from Senator Aiken’s suggestion that the US declare victory unilaterally in Vietnam and get out, then the apposite Vietnam quote for the strategy of abandoning group selection in order to promote altruism by the Buddhist monk author, Matthieu Ricard, comes from a major in Bến Tre province: “We had to destroy that village in order to save it.”
Come to think of it, it was a Buddhist monk in Vietnam who provided the paradigmatic example of altruistic self-sacrifice in service to one’s group.
Or sociologists. I’ve noticed that Spiritual writings which invoke science are very fond indeed of taking beliefs and theories which were discarded decades or even centuries ago and proclaiming them now accepted and settled. I’m thinking in particular of vitalism, dualism, and quantum physics showing us that matter depends on consciousness. If you read what comes out of the Spiritual crowd, they’ve all won and materialism is dead.
One of the first things I wonder when someone otherwise reasonable suddenly seems otherwise is “okay — who are they hanging around with?”
If you use Firefox then: Paywall Pass gets you through with a button click. It automates a procedure that’s universally available in the Google search engine.
There seems to be a semantic issue. If “altruism” can only properly be used in a context of genetic self-sacrifice, then what is the word for helping another when the cost is not fatal? A woman who nurses an abandoned baby while also nursing her own, does not sacrifice her own baby’s reproductive future.
My understanding is that a nursing woman is less likely to get pregnant again while doing so — such that, by doing so, she may be partially or temporarily sacrificing her “reproductive fitness.” If so — and if the woman is wet-nursing a non-consanguineous child without compensation or the expectation of future compensation — then I think that would qualify as “biological altruism.”
I’m no expert in biology (or on lactation, for that matter), and my own commitment to altruism sometimes falters, but that’s my speculative, amateur take on the matter, anyway.
Various hunter gatherers have been observed letting abandoned primate infants suckle alongside a human baby.
‘There seems to be a semantic issue. If “altruism” can only properly be used in a context of genetic self-sacrifice…’
The sense of “altruism” that’s being used here is a technical sense, used in evolutionary biology. There’s no reason you can’t also use the word in its ordinary sense.
There seems to be a semantic issue. If “altruism” can only properly be used in a context of genetic self-sacrifice,
Strictly speaking, it shouldn’t. Biological altruism is about an individual harming or even destroying its fitness (i.e. survival and reproductive chances) in order to improve another’s. The point is that, in selfish gene theory, this should not be genuine altruism but a form of selfishness.
Kin selection provides one way to resolve this. It explains some biological altruism by pointing out that the beneficiary also carries (or likely carries) a copy of the gene. Basically, it’s helping itself. So apparent self-sacrifice of individuals is actually like a chess side sacrificing a pawn in order to give the queen a much better shot.
If genuine genetic altruism occurred, and doesn’t get wiped out of the gene pool, then we’d have to leave the selfish gene theory and explain its persistence some other way.
You seem to be someone that might have an idea about the answer to my question at the bottom of the comments (#23). Being a couple of weeks late here I fear it will get left unanswered, so I draw your attention to it with the hope you might be able to help. Thanks 🙂
sub
“…or the hijacking of behaviors that evolved by kin selection…” I never saw it formulated so succinctly (although I would have added ‘and reciprocal altruism’).
Religion as an attempt at group selection, I really like that hypothesis.
Excellent post.
Wilson recently had a conversation with Tom Stoppard, the playwright, in which Wilson claims that that group selection is now the accepted theory. Link is:
https://evolution-institute.org/article/the-playwright-and-the-scientist-a-conversation-between-tom-stoppard-and-david-sloan-wilson/
If we reject group selection, then by what means did the behavior of norm enforcement arise? E.g. I saw a news story the other day about a man who had told two youths to stop urinating in an alley. They beat him half to death.
He was enforcing a norm, at significant risk to himself. And in evolutionary history, such a confrontation would have been even more risky than in todays society with its effective law enforcing institutions. It is easy to see how the group could benefit from his actions, but what about him?
The rewards granted to you by others for enforcing norms seem limited, but even if that is what drives it, why would anyone reward others for such behavior? The problem remains – why not just let others reward the ‘altruists’?
I am no more convinced by EO Wilson or David Sloan Wilson than anyone else here. But I do struggle to see how behaviors like norm enforcement or intense feelings of patriotism and the behaviors they result in can be explained by conventional kin or reciprocal altruism.
I’m not sure I see the problem. If someone is peeing in my yam plot, it’s in my interest to stop them. If it’s a communal yam plot, it’s in everyone’s interest (including mine) to stop them. So it’s not clear why you think this should be classified as an instance of altruism.
In a village context, reputation matters. Peeing in the yam plot won’t make you any friends, but neither will being known as the guy who lets people get away with peeing in the yam plot. People keep track, and free riders who consistently fail to do their duty as norm enforcers will be noticed and dealt with.
Also, it could originally have been only the alpha males (or females, where applicable) that enforced norms. Being in control enhanced their fitness as long as they could defend their status.
Thanks for the replies.
@Gregory
It was in his interest for the urinating not to happen, though the gain is minimal. It is not in his interest to do the confrontation himself. Such a strategy leaves room for cheaters who don’t enforce, but benefit from someone else doing the confronting.
Had he just walked past without doing anything, the loss to his reputation will be extemely minimal, especially given that he was, iirc, fairly old and thus people would not expect him to take this on himself. But even if there is status of some kind to be gained from enforcing norms, and this status entails raised fitness, that is at the expense of somebody else. Status is relative. Somebody else has to do something altruistic in order that the enforcer gains fitness. Why do that? again, why not let others do it?
Its the same problem with the firemen. They save people for altruism. But ok, its not really altruism, they do if for fitness that comes from others raising your status. But why raise their fitness versus your own, why not let others do it? Ok, so somebody judges you harshly for not giving to the Volunteer Fire Dept, but why them? Why don’t they let someone else confront me? So on ad infinitum.
Its the same with ‘politics’. Lets say you hear someone say something racist. Confront them? Altruism? Maybe you say its for status from other people that don’t like racism. But if you are one of these others, why sacrifice your own fitness for the confronter? Why not let others do it?
I’ve repeated myself a lot here I realise, I’m just trying to make my point clear.
@Diane
Maybe I’m missing your point but this seems unlikely since we all experience instances of anger at some norm breaking behavior. It doesn’t seem likely there is some programme that says ‘if you are dominant, enforce norms, else do not’.
Your question was “by what means did the behavior of norm enforcement arise?” The correct context for answering that question is not the modern urban environment of volunteer firemen and violent strangers lurking in alleys. It’s the tribal or village context of our evolutionary past, in which norms were enforced neighbor to neighbor, and free riders were easily identified.
Asking how these behaviors benefit us now does not address the question of how they arose in the first place.
I agree about the right context, but I don’t see how that solves the problem. Enforcing norms is altruistic unless you get rewards from someone else. But rewarding enforcers is also altruistic unless they get rewards from someone else. And so on.
At some level – either the original norm enforcement, or rewarding someone for enforcing a norm, or rewarding someone who has rewarded someone for enforcing a norm, etc, – somebody is being altruistic.
People might judge you for breaking a norm, or not enforcing it, but with each stage that judgement decreases.
E.g. you might judge someone for swearing, and possibly judge someone for not getting annoyed at someone else for swearing, but did you ever get annoyed at someone for not getting annoyed at someone for not judging someone that swore? Eventually we reach a level where free riders can get away with it. And when they eventually do, those at the next level can then become free riders. Right up to the top.
I still don’t get why you think this must be true. If someone in my social group is behaving badly, then I benefit directly from suppressing that bad behavior (and from encouraging others to help me suppress it). I don’t need a reward from a third party to enforce the norms of good behavior; the benefit of living in a more congenial group is sufficient.
The problem is that strategy is vulnerable to invasion by the strategy of letting other people do the enforcing. You take the risk, and if it works, you get the benefit. But I stand back and let you take that risk. I too get the benefit if it works, but do not have the downside of the risk of the enforcing going wrong.
[And therefore the genes for my strategy spread at the expense of the genes for yours. Thus humanity becomes like me. Yet humanity is not like that as far as I can tell.]
You have the downside that your neighbors will notice you standing back and letting someone else take the risk. And that will cost you next time you need a favor from someone. Why should they help you if you refuse to help them? By trying to exploit the group for your own benefit, you forego some of the benefits of group membership.
So your free-rider strategy isn’t the clear win you think it is; as soon as it starts to gain a foothold, it puts selection pressure on your neighbors to detect and counter it. This is why we have moral intuitions about honesty, fair play, and reciprocity.
You’re making the common mistake of thinking that all of a given species’ evolutionary traits will be selected for the same way. (Poorly expressed, but bear with me.) On the contrary, traits will remain in the gene pool to the extent that they’re fit under certain conditions. If those conditions are rare, they will start to diminish, until the rare situation arises again and they thus gain in fitness again. So variability is maintained in a population to the extent that under some conditions it proves important.
That was going to be my response, too–that the question was, “how did this arise,” not how has it been maintained.
With humanity one has to start allowing for non-evolutionary reinforcement (i.e., cultural, economic, etc.) at some point.
I agree with the first part. The modern examples were just more readily at hand. You can argue time-lag if you want, but the case needs to be made.
Perhaps you could expand a bit on your second sentence.
I think it’s pretty self-explanatory. And cultural selection is much faster than natural selection.
Maybe I’m just thick, but it is not self-explanatory to me. Help me out?
@Gregory
This is the point I’ve been making over and over. You are suggesting those 3rd party observers do something different to what they would have done, towards me, as a result of my reluctance at enforcing a norm. But why do that? Why should they stick their neck out to punish me or reward the enforcer? This strategy will get invaded by the one that does not do this. The 3rd party that does not get annoyed at me.
This problem does not go away by invoking more parties, it just gets pushed back.
Why do you characterize it as “sticking their neck out”? Their choice is whether or not to include you in the circle of reciprocal favor-granting. If you consistently fail to demonstrate willingness to reciprocate, excluding you is the lesser risk and the smarter strategy for them. I don’t see how that’s vulnerable to invasion by a strategy that ignores reputation and blindly trusts everyone.
But I am not demonstrating a lack of willingness to reciprocate. It is in my selfish interest to carry on being a good reciprocal altruist. If you refuse to deal with me, then it is to your own cost as well as mine.
I continue to persue a good reciprocal altruist strategy, I just don’t enforce norms.
That seems like hair-splitting to me. Stepping up and being the enforcer from time to time, in the expectation that others will do the same in their turn, is part of the cycle of reciprocity. By exempting yourself from this social duty, by accepting that favor with no intention of returning it, you are in fact not pursuing a good reciprocal altruist strategy; you’re pursuing a selective strategy, and hoping nobody will notice your occasional defections.
Or if we do notice, you’re hoping that being caught shirking on norm enforcement won’t damage your reputation in other respects. But I don’t think it works that way; the line between norm enforcement and other exchanges of favors isn’t that sharp. If you’re willing to cheat on this, maybe you’re willing to cheat on other things as well. Once trust has been undermined, it pays us to be cautious in all our dealings with you.
That’s my take on it anyway. You’re free to disagree, of course, but I don’t see how treating norm enforcement as distinct from other forms of reciprocity explains the actual facts of human behavior any better.
Its not hair splitting if the two strategies of norm enforcer and individual reciprocal altruist are not inextricably bound up together. If it is possible from a genetic/developmental perspective to create a brain that is only a norm enforcer or only an reciprocal altruist or both or neither. That seems perfectly possible to me.
If you want to imagine what such a person would look like it would be that friend that is totally chill about everything. A super-nice guy that you can always rely on when you are in a bind. BUT he does not care when he hears someone be racist or when he sees someone urinate on a park bench.
If you think you would get annoyed with that guy, and that is why his is a bad strategy, then we just push it back further. Do you also get annoyed with your other friend who does not get annoyed with Chill guy when he doesn’t enforce norms?
As for ‘if you’re willing to cheat on this..’, that’s the same issue. You’re assuming the two strategies must be tied up together. If that is the case then it makes sense to take that skeptical approach towards me. But if they are not, and I really am a good reciprocal altruist on an individual level, just not a norm enforcer, then your strategy to assume I am the former because I am the latter is just another bad strategy that will hurt you versus people that see that I am one but not the other.