A Different Kind of Animal: How Culture Transformed Our Species (University Center for Human Values)

This is a pretty easy to access book on Cultural evolution and how Culture transformed our species to a different kind of animal than our biological cousins like the chimpanzee. The writer is Robert Boyd and the book describes the results of a life-long research project of Boyd and other cultural anthropologists like Pete Richerson. The project started in early 80ies and the contribution of Richerson and Boyd to the subject of Human Evolution has been enormous.As a non-professional evolutionary enthusiast, I learned about Richerson and Boyd first time through the article "Punishment Allows the Evolution of Cooperation (or Anything Else) in Sizable Groups". Technically punishment together with the diversity of norms in human societies are the two factors which make it possible for (cultural) group selection to act on human groups.The DNA studies of recent days show that humans - dislike our nearest relatives like the Neanderthals or the eusocial insects like ants - have been able to co-operate in large groups of non-relatives for long times. How such co-operation has been possible is shown by the theory of Richerson and Boyd and the story is told in the book.Cumulative cultural evolution and human adaptation to almost all environments on the earth is besides evolution of co-operation between non-relatives discussed in the book.

The book consists of two lectures by Robert Boyd, followed by some critical remarks (made by a biologist, a behavioral ecologist, a philosopher and an economist), plus Boyd's reply to his critics. I'll focus on the parts from Robert Boyd, since the critical discussion in part two is rather technical, with little relevance for the 'big picture'.Why are humans different ? Humans have the largest geographical and ecological range of any terrestrial vertebrate, and our biomass is many times the biomass of all wild terrestrial vertebrate species combined. The history of Homo sapiens is a success story. What are the reasons underpinning our success?The standard, somewhat self-congratulatory answer to this question is that we are very smart.According to Boyd, just being smart cannot be the whole answer. He proposes two other reasons:a) Transgenerational cumulative cultureb) Cooperation in large groups of unrelated individualsBecause both a) and b) are not to be found in any other animal, biology or sociobiology cannot account for them.Humans do not learn and adapt as individuals, like other animals. We are much better at learning from others than other species are, and the results of these learning processes accumulate so that each individual 'stands on the shoulders' of past generations. This capacity allows humans to accumulate pools of adaptive information that exceed theinventive capacities of individuals. Cumulative cultural evolution, not individual learning, is the key to human adaptation.Boyd stresses that humans are intrinsically motivated to copy information and practices, especially from successful individuals, and that they even copy information while ignoring the reason why idea X or practice Y is useful; they adopt beliefs and practices just because that’s what the people around them believe and do.This is one of the basic (cognitive) processes responsable for cultural evolution. But how are cultural and biological evolution linked? Boyd writes: „Genes affect what people decide, and what people decide affects the behaviors that models perform in the next generation. So the genetic evolution and cultural change are coupled, a process called 'geneculture coevolution'. […] The account of cultural evolution I am giving here predicts that history will influence cultural adaptation in the same way that history influences genetic adaptation.“What does Boyd's concept of „cultural adaptation“ mean? In biology, an adaptation is any stable trait or behavior that has a positive influence on the 'fitness' of an organism, its probability to survive in an environment and to reproduce its genes. The body with its traits is but a means for spreading genes. Genes are pulling the strings by providing 'recipes' for building vehicles (ranging in size from viruses to whales), and success can be (roughly) measured by counting allel frequencies.But what does „adaptation“ and „success“ mean in culture?There are two possible answers. (a) Culture is a means for humans to cope with all kinds of problems and challenges. Artifacts, languages, ideas, norms, rituals, taboos, etc... are for us what dams are for beavers: an 'extended phenotype' (Richard Dawkins)Or (b) culture is two-faced: sometimes cultural traits and variants like ideas, norms, practices etc... help humans survive and reproduce (like mutualists), but sometimes they acquire a life of their own, they have their own evolutionary dynamic, their own fitness, their own 'strategies', their own success (like parasites or commensalists).If I understand Boyd correctly – but imo he is not very clear about that point -, he favors option (a) -Quote: „...culture can’t override biology. It can’t because culture is as much a part of human biology as our peculiar pelvis.“ -From this perspective, when culture is maladaptive, it is (a) because a tradition with its inherent 'inertia' is lagging behind, unable to cope with recent environmental change, not because a cultural entity has evolved independently, away from human needs, away from being a human adaption. Or (b) a model-based bias like „imitate successful and prestigious people“ goes awry if those prestigious people happen to embrace a stupid idea. Anyway, a 'maladaption' is always a collateral damage of cultural adaption, seen from the human's point of view.But many traditions are not, and have never been adaptive. Examples abound: to sequester menstruating women ; eating the brain of the deceased ; astrology; smoking tobacco ; celibacy; believing in witches; foot binding (of Chinese girls); killing valuable livestock or even humans to placate ancestors or gods; the mutilation of female genitals ; blood-letting ; doing extreme sports ; etc...Boyd's basically functionalist theory cannot account for cases like these, when traditions acquire 'a life of their own', beyond any adaptive function. What the author does not see: What may look like a 'maladaption' from the human's point of view ( the 'host') may be an adaption from the perspective of those ideas, norms, rituals ....- - - - - - -Another core mechanism of cultural evolution, according to Boyd, is „cultural group selection“. He is not happy with this expression: „If I had to do it all over again, I would not use the term 'cultural group selection,' […] it would have been wiser to use the term […] 'group-structured cultural selection'.“Boyd does not like the expression >cultural group selection< because it is ambiguous; it can be parsed in two ways:(cultural [group selection]) or ([cultural group] selection).In the first case, it is just the well-known concept of group selection, but this time not in the sphere of biology, but in the sphere of culture. That's not what Boyd has in mind. His solution is the second version: There are groups that exist on the basis of cultural traits, and there is selection among these groups-consisting-of-cultural-traits.An example we are all acquainted with (Boyd does not mention it, but I think it is quite helpful) are firms. Each firm is a kind of „cultural group“; it is constituted of laws, rules, routines, etc... An important aspect is that in biology, group selection is weak or even absent if there is a lot of migration between groups, because biological groups are built of individuals; and when individuals migrate, their traits migrate with them.In cultural groups the focus is less on individual members, but on norms, values, ideas, practices. Therefore migration among firms – to take my example – does not threaten the effectiveness of group selection if migrating individuals adopt the dominant ideas, norms, rules of the new group (or firm). Individuals in this perspective are just temporary representatives or vehicles of specific norms.Boyd is absolutely right when he dismisses efforts to explain the extraordinary human cooperativeness with direct or indirect reciprocity, as many sociobiologists tend to do. Reciprocity may work in small-scale societies (like bands of foragers), but not in large-scale societies as they dominate the human world since the agricultural revolution. Boyd shows convincingly that human cooperation is fostered and maintained by NORMS members of any society (small and large-scale!) adopt early in their life. To put it metaphorically: Norms and their enforcement by third-party punishment are the OS of all human societies, be they small or large.I welcome Boyd's focus on norms, but I think that something important is missing in his picture: For want of a better expression, I'd call it 'tribal emotions'. People don't adopt a n y norm that happens to be around, not even any successful norm. We are not compulsive norm-adopters. We tend to adopt norms, beliefs etc.. that are the norms , beliefs or practices of o u r 'tribe'. Groups tend to remain loyal to their o w n culture, even if it condems them to backwardness. The tribal bias of 'doing it o u r way' often trumps 'success'. (Otherwise Arabs or Russians would have adopted lots of norms and ideas and institutions from successful Europeans during the last two centuries, like the Japanese did after 1870, but smart Japan was the exception.)Boyd writes: “living in societies in which norm violators suffered serious sanctions led to the genetic evolution of moral sentiments that caused people to be more cooperative, trusting, and willing to obey and enforce norms than otherprimates.” -I think it is the other way round: The genetic evolution of (proto-)moral sentiments (read any book written by Frans de Waal to get the details) predates our cultural evolution, including the evolution of culturally transmitted norms. Because they need language for their transmission, ideational norms were 'latecomers' to the scene; they co-opted and latched on to older evolved cognitive biases and emotions, be they proto-moralistic or tribalistic (in-group bias; or 'joint attention' à la Tomasello).Although Boyd clearly focuses on norms, unfortunately he does not dare to 'leap' and come to the – in my view – logical conclusion: That the focal entities in cultural evolution are not individuals or even groups of individuals, but non-genetically transmitted pieces of information: ideas, norms, practices … or what others have called 'memes'.Boyd writes: „...competition among groups can lead to the spread of some norms at the expense of others“.„Norms causing a group to survive will become more common compared to those that lead to extinction“.That is very close to what Dan Dennett or Richard Dawkins would call a 'meme's-centered view' of cultural evolution.In biological evolution, the last sentence would be like this: „Genes causing an organism to survive and reproduce (compared to other organisms) will become more common compared to those that lead to a reduction of fitness or even death“. Therefore, imo the logical conclusion of „cultural group selection“ would be a 'meme's-centered view' of cultural evolution, but since Boyd does not like the concept of 'memes' he continues to speak of 'norms', sometimes in a rather ambiguous way.Because Boyd (mostly) limits himself to talking about norms in the book, he misses the Big Picture of cultural evolution. That is obvious when we read sentences like this one: „I am not keen on folktales as evidence about past societies. The problem is that the content of such tales is not determined by some social function, but instead by what people find interesting and memorable,...“ - - That is true, but a lot of culture is made of tales, jokes, recipes, tunes, body adornment, fashion, gestures, beliefs and so on … etc... - short: ideas and practices that do not primarily serve some function for survival.That is one of the weaker points of Boyd's book: His poster examples from anthropological studies make perfect sense in a functionalist framework, as they are all about norms that have a strong (positive) effect on survival of HUMAN beings (useful food taboos, detoxifying material to obtain food, building shelters, etc..), but many, maybe even most of cultural variants (aka 'memes') do not have such effects. A lot of those entities culture is made of exist - and are reproduced - just because people find them interesting and memorable. That is exactly what is predicted by scholars who consider cultural variants aka 'memes' as a second replicator with its own independent 'fitness'.Cultural group selection, or 'group-structured cultural selection', as Boyd would prefer it, brought to its logical conclusion would be a kind of meme theory: Memes are to groups in culture what genes are to individuals (in biology).Human history of the last 20.000 years with its unique dynamic can only be understood if we focus no longer on humans and their needs, but on cultural entities and their own evolutionary dynamic. These entities are not inert like badges or tools, waiting to be used by humans, but they can be seen as evolutionary 'agents'.Applying the theory of multi-level selection we could say: On an elementary level, there is selection of single cultural variants (ideas, norms, practices), on the level above there is selection of bundles of them (a religion, a philosophy, a complex ritual), and finally there is also selection of 'cultural groups' like firms or ethnic groups that are based on, and built of bundles of cultural variants. This multi-level approach predicts that there would be tensions between these levels: an idea or practice can spread on its own level although it is detrimental on the level of the group; functioning groups can be subverted by 'rogue memes' (like organisms can be killed by viruses or bacteria).As I see it, there is a striking analogy with levels of selection in biology : gene, genome, cell, individual organism, groups of individuals. So-called rogue genes can spread even if they are detrimental to the genome or the organism. Cells can proliferate at the expense of the organism.... In biology all these entities on its different levels are 'targets of selection', but – and this is crucial - there is only one logical candidate for the position of 'unit of evolution': the gene. Why? Cells or individuals per se do not evolve, because they lack a specific mechanism for inheritance.In a unified theory of cultural evolution, the logical candidate for the position of 'unit of evolution' would be the meme (= norms, ideas, artifacts, practices etc...). Whatever happens on the level of the group does not form lineages and therefore it does not evolve, because groups have no group-specific mechanism of cultural inheritance. As there is no evolution of the individual in biology, there is no evolution of groups in culture, even if groups are targets of selection processes.

Robert Boyd is one of most respected evolutionary anthropologists, that since the 80's with Peter Richerson tried to develop and apply mathematical modelling to cultural evolution. Here, almost without an equation, he gives us a perspective of what he and his colleagues have found, when started to apply their models to the real situations. Reading it will change your thinking about humans and the evolution of culture and behaviour of our species.

The book consists of two lectures by Robert Boyd, followed by some critical remarks (made by a biologist, a behavioral ecologist, a philosopher and an economist), plus Boyd's reply to his critics. I'll focus on the parts from Robert Boyd, since the critical discussion in part two is rather technical, with little relevance for the 'big picture'.Why are humans different ? Humans have the largest geographical and ecological range of any terrestrial vertebrate, and our biomass is many times the biomass of all wild terrestrial vertebrate species combined. The history of Homo sapiens is a success story. What are the reasons underpinning our success?The standard, somewhat self-congratulatory answer to this question is that we are very smart.According to Boyd, just being smart cannot be the whole answer. He proposes two other reasons:a) Transgenerational cumulative cultureb) Cooperation in large groups of unrelated individualsBecause both a) and b) are not to be found in any other animal, biology or sociobiology cannot account for them.Humans do not learn and adapt as individuals, like other animals. We are much better at learning from others than other species are, and the results of these learning processes accumulate so that each individual 'stands on the shoulders' of past generations. This capacity allows humans to accumulate pools of adaptive information that exceed theinventive capacities of individuals. Cumulative cultural evolution, not individual learning, is the key to human adaptation.Boyd stresses that humans are intrinsically motivated to copy information and practices, especially from successful individuals, and that they even copy information while ignoring the reason why idea X or practice Y is useful; they adopt beliefs and practices just because that’s what the people around them believe and do.This is one of the basic (cognitive) processes responsable for cultural evolution. But how are cultural and biological evolution linked? Boyd writes: „Genes affect what people decide, and what people decide affects the behaviors that models perform in the next generation. So the genetic evolution and cultural change are coupled, a process called 'geneculture coevolution'. […] The account of cultural evolution I am giving here predicts that history will influence cultural adaptation in the same way that history influences genetic adaptation.“What does Boyd's concept of „cultural adaptation“ mean? In biology, an adaptation is any stable trait or behavior that has a positive influence on the 'fitness' of an organism, its probability to survive in an environment and to reproduce its genes. The body with its traits is but a means for spreading genes. Genes are pulling the strings by providing 'recipes' for building vehicles (ranging in size from viruses to whales), and success can be (roughly) measured by counting allel frequencies.But what does „adaptation“ and „success“ mean in culture?There are two possible answers. (a) Culture is a means for humans to cope with all kinds of problems and challenges. Artifacts, languages, ideas, norms, rituals, taboos, etc... are for us what dams are for beavers: an 'extended phenotype' (Richard Dawkins)Or (b) culture is two-faced: sometimes cultural traits and variants like ideas, norms, practices etc... help humans survive and reproduce (like mutualists), but sometimes they acquire a life of their own, they have their own evolutionary dynamic, their own fitness, their own 'strategies', their own success (like parasites or commensalists).If I understand Boyd correctly – but imo he is not very clear about that point -, he favors option (a) -Quote: „...culture can’t override biology. It can’t because culture is as much a part of human biology as our peculiar pelvis.“ -From this perspective, when culture is maladaptive, it is (a) because a tradition with its inherent 'inertia' is lagging behind, unable to cope with recent environmental change, not because a cultural entity has evolved independently, away from human needs, away from being a human adaption. Or (b) a model-based bias like „imitate successful and prestigious people“ goes awry if those prestigious people happen to embrace a stupid idea. Anyway, a 'maladaption' is always a collateral damage of cultural adaption, seen from the human's point of view.But many traditions are not, and have never been adaptive. Examples abound: to sequester menstruating women ; eating the brain of the deceased ; astrology; smoking tobacco ; celibacy; believing in witches; foot binding (of Chinese girls); killing valuable livestock or even humans to placate ancestors or gods; the mutilation of female genitals ; blood-letting ; doing extreme sports ; etc...Boyd's basically functionalist theory cannot account for cases like these, when traditions acquire 'a life of their own', beyond any adaptive function. What the author does not see: What may look like a 'maladaption' from the human's point of view ( the 'host') may be an adaption from the perspective of those ideas, norms, rituals ....- - - - - - -Another core mechanism of cultural evolution, according to Boyd, is „cultural group selection“. He is not happy with this expression: „If I had to do it all over again, I would not use the term 'cultural group selection,' […] it would have been wiser to use the term […] 'group-structured cultural selection'.“Boyd does not like the expression >cultural group selection< because it is ambiguous; it can be parsed in two ways:(cultural [group selection]) or ([cultural group] selection).In the first case, it is just the well-known concept of group selection, but this time not in the sphere of biology, but in the sphere of culture. That's not what Boyd has in mind. His solution is the second version: There are groups that exist on the basis of cultural traits, and there is selection among these groups-consisting-of-cultural-traits.An example we are all acquainted with (Boyd does not mention it, but I think it is quite helpful) are firms. Each firm is a kind of „cultural group“; it is constituted of laws, rules, routines, etc... An important aspect is that in biology, group selection is weak or even absent if there is a lot of migration between groups, because biological groups are built of individuals; and when individuals migrate, their traits migrate with them.In cultural groups the focus is less on individual members, but on norms, values, ideas, practices. Therefore migration among firms – to take my example – does not threaten the effectiveness of group selection if migrating individuals adopt the dominant ideas, norms, rules of the new group (or firm). Individuals in this perspective are just temporary representatives or vehicles of specific norms.Boyd is absolutely right when he dismisses efforts to explain the extraordinary human cooperativeness with direct or indirect reciprocity, as many sociobiologists tend to do. Reciprocity may work in small-scale societies (like bands of foragers), but not in large-scale societies as they dominate the human world since the agricultural revolution. Boyd shows convincingly that human cooperation is fostered and maintained by NORMS members of any society (small and large-scale!) adopt early in their life. To put it metaphorically: Norms and their enforcement by third-party punishment are the OS of all human societies, be they small or large.I welcome Boyd's focus on norms, but I think that something important is missing in his picture: For want of a better expression, I'd call it 'tribal emotions'. People don't adopt a n y norm that happens to be around, not even any successful norm. We are not compulsive norm-adopters. We tend to adopt norms, beliefs etc.. that are the norms , beliefs or practices of o u r 'tribe'. Groups tend to remain loyal to their o w n culture, even if it condems them to backwardness. The tribal bias of 'doing it o u r way' often trumps 'success'. (Otherwise Arabs or Russians would have adopted lots of norms and ideas and institutions from successful Europeans during the last two centuries, like the Japanese did after 1870, but smart Japan was the exception.)Boyd writes: “living in societies in which norm violators suffered serious sanctions led to the genetic evolution of moral sentiments that caused people to be more cooperative, trusting, and willing to obey and enforce norms than otherprimates.” -I think it is the other way round: The genetic evolution of (proto-)moral sentiments (read any book written by Frans de Waal to get the details) predates our cultural evolution, including the evolution of culturally transmitted norms. Because they need language for their transmission, ideational norms were 'latecomers' to the scene; they co-opted and latched on to older evolved cognitive biases and emotions, be they proto-moralistic or tribalistic (in-group bias; or 'joint attention' à la Tomasello).Although Boyd clearly focuses on norms, unfortunately he does not dare to 'leap' and come to the – in my view – logical conclusion: That the focal entities in cultural evolution are not individuals or even groups of individuals, but non-genetically transmitted pieces of information: ideas, norms, practices … or what others have called 'memes'.Boyd writes: „...competition among groups can lead to the spread of some norms at the expense of others“.„Norms causing a group to survive will become more common compared to those that lead to extinction“.That is very close to what Dan Dennett or Richard Dawkins would call a 'meme's-centered view' of cultural evolution.In biological evolution, the last sentence would be like this: „Genes causing an organism to survive and reproduce (compared to other organisms) will become more common compared to those that lead to a reduction of fitness or even death“. Therefore, imo the logical conclusion of „cultural group selection“ would be a 'meme's-centered view' of cultural evolution, but since Boyd does not like the concept of 'memes' he continues to speak of 'norms', sometimes in a rather ambiguous way.Because Boyd (mostly) limits himself to talking about norms in the book, he misses the Big Picture of cultural evolution. That is obvious when we read sentences like this one: „I am not keen on folktales as evidence about past societies. The problem is that the content of such tales is not determined by some social function, but instead by what people find interesting and memorable,...“ - - That is true, but a lot of culture is made of tales, jokes, recipes, tunes, body adornment, fashion, gestures, beliefs and so on … etc... - short: ideas and practices that do not primarily serve some function for survival.That is one of the weaker points of Boyd's book: His poster examples from anthropological studies make perfect sense in a functionalist framework, as they are all about norms that have a strong (positive) effect on survival of HUMAN beings (useful food taboos, detoxifying material to obtain food, building shelters, etc..), but many, maybe even most of cultural variants (aka 'memes') do not have such effects. A lot of those entities culture is made of exist - and are reproduced - just because people find them interesting and memorable. That is exactly what is predicted by scholars who consider cultural variants aka 'memes' as a second replicator with its own independent 'fitness'.Cultural group selection, or 'group-structured cultural selection', as Boyd would prefer it, brought to its logical conclusion would be a kind of meme theory: Memes are to groups in culture what genes are to individuals (in biology).Human history of the last 20.000 years with its unique dynamic can only be understood if we focus no longer on humans and their needs, but on cultural entities and their own evolutionary dynamic. These entities are not inert like badges or tools, waiting to be used by humans, but they can be seen as evolutionary 'agents'.Applying the theory of multi-level selection we could say: On an elementary level, there is selection of single cultural variants (ideas, norms, practices), on the level above there is selection of bundles of them (a religion, a philosophy, a complex ritual), and finally there is also selection of 'cultural groups' like firms or ethnic groups that are based on, and built of bundles of cultural variants. This multi-level approach predicts that there would be tensions between these levels: an idea or practice can spread on its own level although it is detrimental on the level of the group; functioning groups can be subverted by 'rogue memes' (like organisms can be killed by viruses or bacteria).As I see it, there is a striking analogy with levels of selection in biology : gene, genome, cell, individual organism, groups of individuals. So-called rogue genes can spread even if they are detrimental to the genome or the organism. Cells can proliferate at the expense of the organism.... In biology all these entities on its different levels are 'targets of selection', but – and this is crucial - there is only one logical candidate for the position of 'unit of evolution': the gene. Why? Cells or individuals per se do not evolve, because they lack a specific mechanism for inheritance.In a unified theory of cultural evolution, the logical candidate for the position of 'unit of evolution' would be the meme (= norms, ideas, artifacts, practices etc...). Whatever happens on the level of the group does not form lineages and therefore it does not evolve, because groups have no group-specific mechanism of cultural inheritance. As there is no evolution of the individual in biology, there is no evolution of groups in culture, even if groups are targets of selection processes.