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kin selection – some fascinating stuff

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meerkats get together for ye olde family snap

Canto: So we’ve done four blogs on Palestine and we’ve barely scratched the surface, but we’re having trouble going forward with that project because, frankly, it’s so depressing and anger-inducing that it’s affecting our well-being.

Jacinta: Yes, an undoubtedly selfish excuse, but we do plan to go on with that project – we’re definitely not abandoning it, and meanwhile we should recommend such books as Tears for Tarshiha by the Palestinian peace activist Olfat Mahmoud, and Goliath by the Jewish American journalist Max Blumenthal, which highlight the sufferings of Palestinian people in diaspora, and the major stresses of trying to exist under zionist monoculturalism. But for now, something completely different, we’re going to delve into the fascinating facts around kin selection, with thanks to Robert Sapolski’s landmark book Behave. 

Canto: The term ‘kin selection’ was first used by John Maynard Smith in the early sixties but it was first mooted by Darwin (who got it right about honey bees), and its mathematics were worked out back in the 1930s. 

Jacinta: What’s immediately interesting to me is that we humans tend to think we alone know who our kin are, especially our extended or most distant kin, because only we know about aunties, uncles and second and third cousins. We have language and writing and record-keeping, so we can keep track of those things as no other creatures can. But it’s our genes that are the key to kin selection, not our brains.

Canto: Yes, and let’s start with distinguishing between kin selection and group selection, which Sapolsky deals with well. Group selection, popularised in the sixties by the evolutionary biologist V C Wynne-Edwards and by the US TV program Wild Kingdom, which I remember well, was the view that individuals behaved, sometimes or often, for the good of the species rather than for themselves as individuals of that species. However, every case that seemed to illustrate group selection behaviour could easily be interpreted otherwise. Take the case of ‘eusocial’ insects such as ants and bees, where most individuals don’t reproduce. This was seen as a prime case of group selection, where individuals sacrifice themselves for the sake of the highly reproductive queen. However, as evolutionary biologists George Williams and W D Hamilton later showed, eusocial insects have a unique genetic system in which they are all more or less equally ‘kin’, so it’s really another form of kin selection. This eusociality exists in some mammals too, such as mole rats. 

Jacinta: The famous primatologist Sarah Hrdy dealt something of a death-blow to group selection in the seventies by observing that male langur monkeys in India commit infanticide with some regularity, and, more importantly, she worked out why. Langurs live in groups with one resident male to a bunch of females, with whom he makes babies. Meanwhile the other males tend to hang around in groups brooding instead of breeding, and infighting. Eventually, one of this male gang feels powerful enough to challenge the resident male. If he wins, he takes over the female group, and their babies. He knows they’re not his, and his time is short before he gets booted out by the next tough guy. Further, the females aren’t ovulating because they’re nursing their kids. The whole aim is to pass on his genes (this is individual rather than kin selection), so his best course of action is to kill the babs, get the females ovulating as quickly as possible, and impregnate them himself. 

Canto: Yes, but it gets more complicated, because the females have just as much interest in passing on their genes as the male, and a bird in the hand is worth two in the bush…

Jacinta: Let me see, a babe in your arms is worth a thousand erections?

Canto: More or less precisely. So they fight the male to protect their infants, and can even go into ‘fake’ estrus, and mate with the male, fooling the dumb cluck into thinking he’s a daddy. 

Jacinta: And since Hrdy’s work, infanticide of this kind has been documented in well over 100 species, even though it can sometimes threaten the species’ survival, as in the case of mountain gorillas. So much for group selection.

Canto: So now to kin selection. Here are some facts. If you have an identical twin your genome is identical with hers. If you have a full sibling you’re sharing 50% and with a half-sibling 25%. As you can see, the mathematics of genes and relatedness can be widened out to great degrees of complexity. And since this is all about passing on all, or most, or some of your genes, it means that ‘in countless species, whom you co-operate with, compete with, or mate with depends on their degree of relatedness to you’, to quote Sapolsky. 

Jacinta: Yes, so here’s a term to introduce and then fairly promptly forget about: allomothering. This is when a mother of a newborn enlists the assistance of another female in the process of child-rearing. It’s a commonplace among primate species, but also occurs in many bird species. The mother herself benefits from an occasional rest, and the allomother, more often than not a younger relation such as the mother’s kid sister, gets to practice mothering. 

Canto: So this is part of what is called ‘inclusive fitness’, where, in this case, the kid gets all-day mothering (if of varying quality) the kid sister gets to learn about mothering, thereby increasing her fitness when the time comes, and the mother gets a rest to recharge her batteries for future mothering. It’s hopefully win-win-win. 

Jacinta: Yes, there are negatives and positives to altruistic behaviour, but according to Hamilton’s Rule, r.B > C, kin selection favours altruism when the reproductive success of relatives is greater than the cost to the altruistic individual. 

Canto: To explain that rule, r equals degree of relatedness between the altruist and the beneficiary (aka coefficient of relatedness), B is the benefit (measured in offspring) to the recipient, and C is the cost to the altruist. What interests me most, though, about this kin stuff, is how other, dumb primates know who is their kin. Sapolsky describes experiments with wild vervet monkeys by Dorothy Cheney and Robert Seyfarth which show that if monkey A behaves badly to monkey B, this will adversely affect B’s behaviour towards A’s relatives, as well as B’s relatives’ behaviour to A, as well as B’s relatives’ behaviour to A’s relatives. How do they all know who those relatives are? Good question. The same researchers proved this recognition by playing a recording of a juvenile distress call to a group of monkeys hanging around. The female monkeys all looked at the mother of the owner of that distress call to see what she would do. And there were other experiments of the sort. 

Jacinta: And even when we can’t prove knowledge of kin relations (kin recognition) among the studied animals, we find their actual behaviour tends always to conform to Hamilton’s Rule. Or almost always… In any case there are probably other cues, including odours, which may be unconsciously sensed, which might aid in inclusive fitness and also avoiding inbreeding. 

Canto: Yes and It’s interesting how this closeness, this familiarity, breeds contempt in some ways. Among humans too. Well, maybe not contempt but we tend not to be sexually attracted to those we grow up with and, for example, take baths with as kids, whether or not they’re related to us. But I suppose that has nothing to do with kin selection. And yet…

Jacinta: And yet it’s more often than not siblings or kin that we have baths with. As kids. But getting back to odours, we have more detail about that, as described in Sapolski. Place a mouse in an enclosed space, then introduce two other mice, one unrelated to her, another a full sister from another litter, never encountered before. The mouse will hang out with the sister. This is called innate recognition, and it’s due to olfactory signatures. Pheromones. From proteins which come from genes in the major histocompatibility complex (MHC). 

Canto: Histowhat?

Jacinta: Okay, you know histology is the study of bodily tissues, so think of the compatibility or otherwise of tissues that come into contact. Immunology.  Recognising friend or foe, at the cellular, subcellular level. The MHC, this cluster of genes, kicks off the production of proteins which produce pheromones with a unique odour, and because your relatives have similar MHC genes, they’re treated as friends because they have a similar olfactory signature. Which doesn’t mean the other mouse in the enclosure is treated as a foe. It’s a mouse, after all. But other animals have their own olfactory signatures, and that’s another story. 

Canto: And there are other forms of kin recognition. Get this – birds recognise their parents from the songs sung to them before they were hatched. Birds have distinctive songs, passed down from father to son, since its mostly the males that do the singing. And as you get to more complex species, such as primates – though maybe they’re not all as complex as some bird species – there might even be a bit of reasoning involved, or at least consciousness of what’s going on. 

Jacinta: So that’s kin selection, but can’t we superior humans rise above that sort of thing? Australians marry Japanese, or have close friendships with Nigerians, at least sometimes. 

Canto: Sometimes, and this is the point. Kinship selection is an important factor in shaping behaviour and relations, but it’s one of a multiple of factors, and they all have differential influences in different individuals. It’s just that such influences may go below the level of awareness, and being aware of the factors shaping our behaviour is always the key, if we want to understand ourselves and everyone else, human or non-human.

Jacinta: Good to stop there. As we’ve said, much of our understanding has come from reading Sapolsky’s Behave, because we’re old-fashioned types who still read books, but I’ve just discovered that there’s a whole series of lectures by Sapolsky, about 25, on human behaviour, which employs the same structure as the book (which is clearly based on the lectures), and is available on youtube here. So all that’s highly recommended, and we’ll be watching them.

References

R Sapolski, Behave: the biology of humans at our best and worst. Bodley Head, 2017

https://www.britannica.com/science/animal-behavior/Function#ref1043131

https://en.wikipedia.org/wiki/Kin_selection

https://en.wikipedia.org/wiki/Eusociality

 

 

 

 

 

is this the best use of journalism?: attn Katie McBride and Outline magazine

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Rat Park, in colour

Jacinta: Now we’re going to do something slightly unpleasant but wholly necessary: take someone to task, as teachers must occasionally do.

Canto: Yes, it relates to a previous post, a recent one, about Rat Farm and the war on drugs.

Jacinta: In writing that post we happened upon an article entitled  ‘This 38-year-old study is still spreading bad ideas about addiction” – which kind of shocked me with its provocative title. It was written by Katie MacBride and published by Outline, an online magazine. I only skimmed the article at the time, bemused to find the Rat Park experiment still creating such negative vibes after all these years, but some obvious problems in the article stood out, even on the most cursory reading, so I’ve decided to revisit it with a more careful analysis, with Canto’s help.

Canto: Well the first red flag with the article comes with the first words, before even the title. Pop science. In other words, this article, or rather its subject, should be filed in the category of ‘pop science’, as opposed to real science. This is designed to instil prejudice in the reader from the outset, and is clearly a cheap trick.

Jacinta: Yes, and for an immediate antidote to this kind of cheapsterism, I’d advise anyone to read the Wikipedia article on the rat park experiment, which is calmly and reasonably presented, as is usual. And let me here heap praise on Wikipedia for its general reliability, its objectivity and its pro-science approach. It’s one of the greatest gifts the internet has provided to our world, IMHO.

Canto: The next red flag comes with the title – ’38 years old and still spreading bad ideas’…. As if the date of the study is relevant. There are a number of landmark psychology studies even older than Bruce Alexander’s Rat Park, and also ‘flawed’ – of which more later, – which continue to resonate today for obvious reasons…

Jacinta: Yes, for example Stanley Milgram’s electric shock experiments, over fifty years ago now, and the Stanford Prison experiment of 1971. These, and Alexander’s Rat Park experiment, deserve to be regarded as landmark pieces of work because they make you think. And they often overturn previous thinking. They shake our complacency.

Canto: And what about the latter part of the title, that Alexander’s work is still spreading bad ideas?

Jacinta: It’s interesting that she claims this, considering that the main reason Alexander embarked on this study was to combat bad ideas – particularly the war on drugs itself, and the prevailing view, promoted by the likes of Harry Anslinger and his zero tolerance approach to drugs such as cannabis and cocaine, that use of these drugs led inevitably to a kind of madness that was extremely harmful to self and others. Remember the rat adverts of the time, which showed rats dropping dead after regularly imbibing morphene-laced water, with the message ‘this could happen to you’.

Canto: Yes, and the rats may well have been choosing the drug over plain water because, like many lab rats of the time – hopefully things have changed – the conditions they were kept in made their life something of a living hell. What Alexander’s experiment showed was that, given a far more enriched environment, rats made far less simplistic and self-destroying choices. That’s all. So how could this be a ‘bad idea?’

Jacinta: MacBride doesn’t say. But to be fair, Alexander’s thesis may have been that opiates aren’t addictive at all, which is not what his results showed – they showed that environment matters hugely in respect to the willingness to get hooked on drugs. And that’s a really really important finding, not a ‘bad idea’.

Canto: And we’re still on the title of MacBride’s essay, which is followed by a tiny summary remark, ‘The Rat Park study was flawed and its findings have been oversimplified, but it keeps getting cited.’ Any comments?

Jacinta: Yes – as a regular listener to the podcasts of the Skeptic’s Guide to the Universe (SGU) over the years, as well as a reader of Ben Goldacre and other science-based critics of medical/psychological studies and experiments, I can safely say that every piece of research or experimentation, since the dawn of time, is flawed. Or imperfect. Or limited. Some more than others. of course. So to say the study is flawed is to say nothing at all. Every episode of SGU, and I’ve listened to hundreds, features one piece of published research or other, which Steve Novella picks to pieces to determine whether it’s very or mildly interesting, or a piece of rubbish, but even with the best study, the mantra is generally ‘needs more research’. So a critic needs to show how an experiment is flawed, and how those flaws affect the results. And MacBride’s effort to do this is pretty abysmal.

Canto: Okay, before we examine that effort, I’d like to quote something from early on in MacBride’s article:

The Rat Park study undermined one popular misconception about addiction, that chemistry of drugs is the single most important factor in addiction. But instead of pushing the popular understanding forward, it merely replaced that misconception with a new one: that environment is the most important factor.

What do you make of that? Do you think it a fair description of the study?

Jacinta: It’s an odd description, or mis-description, of the study. The first sentence you quoted isn’t problematic. The study did undermine the idea that it was all about chemistry. Or rather it would have, had anyone paid attention to it. It should have, as MacBride implies, but instead of then regretting that the study didn’t have any impact, she presents it as deserving of oblivion. It doesn’t make much sense.

Canto: The quote claims that it’s a misconception that environment is the most important factor in drug addiction. Do you agree?

Jacinta: I don’t know if it’s the most important factor, but it’s obviously an important factor, and the Rat Park experiment provided strong evidence for this. It seems MacBride is confusing Alexander’s possible claims or commentary on the study with the study itself. The study doesn’t prove that environment is the most important factor, but it certainly makes you think about addiction in a very different way from the horrific but dumb rat ads  that prompted it. It makes you think, as all good studies do, and that’s something MacBride seems extremely reluctant to admit. And I wonder why.

Canto: But MacBride does provide cogent criticisms of the study, doesn’t she?

Jacinta: Well, she quotes one particular critique of the study, by a Dr Sam Snodgrass, who found that the Rat Park environment, in which rats were no longer isolated and therefore mated, as rats are wont to do, would have rendered the findings questionable. According to Snodgrass, “You can’t have one group of subjects mating and with pups and compare it to a group that doesn’t engage in these behaviors and say that the difference between the two groups is caused by environmental differences.” But I beg to differ. An environment in which you’re isolated and unable to have sex is obviously very different from an environment in which you breed as normal – especially for rats. As to the rat pups ruining the experiment, I think if you looked closely at any rat study in which rats get to live together and breed, the actual experiment would be more messy than the published results indicate, but I doubt the problems would be so great as to invalidate those results.

Canto: And what about attempts to replicate the experiment?

Jacinta: Well there seem not to have been enough of them, and that’s not Alexander’s fault. Above all, similar experiments should have been conducted with different drugs and different concentrations etc. And of course rats aren’t humans, and it’s hard to bridge that gap, especially these days, as lab testing of other non-human animals (and rats too) is increasingly frowned upon, for good reason. I note that MacBride briefly mentions that others did replicate Alexander’s results, but she chooses to focus almost wholly on those who found differences. She’s also quite brief in describing the obvious parallel, presented in much greater detail in Johann Hari’s Chasing the scream, of American soldiers taking heavily to heroin in the alienating environment of Vietnam and giving them up on their return to what was for them an obviously more enriched environment. The facts were startling – 20 time the heroin addiction in Vietnam, as MacBride admits – but not much is made of them, as she is more concerned to pour cold water on Rat Park, so to speak.

Canto: Yes it’s strange – MacBride admits that the war on drugs has been an abject failure, but her obsession with criticising Rat Park prevents her from carrying through on that with, for example, the alternatives to this American approach in Europe. She mentions the again startling fact, reported by the Brookings Institute, that the combined hardcore user rate for hard drugs was approximately 4 times higher in the US than in Europe, after decades of the US war on drugs, but fails to note that the Rat Park experiment was one of the main inspirations in implementing more humane and vastly more successful policies, not only in Europe but, more recently, in some US states.

Jacinta: Yes MacBride is clearly concerned to get everyone’s facts straight on the opioid epidemic that’s currently gripping the US, and about which I honestly know little, but I think she has gone overboard in seeking to vilify the Rat Park study, which surely has little to do with that epidemic. The Rat Park experiment hardly promotes drug-taking; what it does strongly suggest, as does Johann Hari’s book, is that environment is one of the most important factors in determining a person’s willingness to escape into drugs. My own personal experience tallies with that, having been brought up in a depressed and disadvantaged region, hard-hit in the seventies by economic recession, and watching the illicit drug trade take off around me, as houses and gardens became more and more derelict.

Canto: Yes, it’s hard to understand why she’s focusing so negatively on Rat Park, when the problem is really one of interpretation, insofar as there is a problem. And I don’t know how it relates negatively to the opioid crisis. Maybe we should find out more about this crisis, and do a follow-up?

Jacinta: Maybe, but it’s so hard trying to fix the world’s problems… but of course that’s what we’re here for…

 

Written by stewart henderson

April 13, 2018 at 11:53 am