Social Structure and Human EvolutionThis page is about human social structure and human social groups. It treats culture as an extended, group phenotype that acts as the evolutionary target for human sexual selection. It summarizes how evolution by sexual selection and group selection, working together, can be expected to "map" human social structure onto sexuality. Hence, it argues, we should expect human sexualities to correlate with the epistemic structure of human social groups.
Social Structure and Human Evolution
Culture as a Human, Extended Phenotype and as the Target for Sexual Selection
Group Selection, Heterogeneity and Social Structure
Human Sexuality is Modified by the Evolution of Social Knowledge
There is no Meme, no Analog to the Gene, in Culture
The Data Flow Model for Evolving Systems
The key points used in the bioepistemic analysis that links human sexuality to human social structure are
- Humans are a sexually selected species.
- Sexual selection involves one gender being sexually attracted by some aspect of the phenotype of the other gender and therefore choosing partners who possess that phenotype in high degree. (The classic example is the peacock's tail.)
- The phenotypes that become the targets for sexual selection include extended phenotypes. (A non-human example is the Bower bird.)
- In most species, females either choose or are fought over, so that sexual selection operates on the male phenotype. However, humans are a pair forming species and both genders must makes a selection to form a pair. Hence, in humans, sexual selection operates on the phenotype of both males and females.
- Besides our physical phenotype, humans have a very large extended phenotype, culture, which is the knowledge associated with human social groups and whose properties are linked to human social structure. Bioepistemic evolution, which incorporates all forms of knowledge into a single evolutionary framework, sees culture as an extended human phenotype and as the target for human sexual selection.
- On that basis, human social structure, culture and the social status of prospective sexual partners, should be factors in human sexual selection.
- Hence, we would expect the properties of social structure to determine the sexual choices humans make and so, over time, to have become mapped onto human sexualities.
- Therefore, to understand human sexuality, we must study human social structure and the properties of human social groups.
Although evolutionary theory always refers to natural selection, two variants of it - sexual selection and group selection - seem very important in human evolution. The Architecture of Thought takes sexual selection, first described by Darwin in the The Descent of Man, to be an important mechanism driving human evolution. It also holds that group selection is an important aspect of human evolution. (Group selection argues that an important aspect of reproductive success or failure is the group to which an individual happens to belong.)
Sexual selection implies that the direction taken by the evolutionary development of a species is driven by the sexual choices made by partners. The classic example of sexual selection is the development of the peacock's tail. In that species, the female's preference for males with a long tail gives rise to a selective pattern of mating that progressively lengthens the male's tail. The structure of this mechanism places a sexuality in one gender, the female, and links it to a phenotype in the other gender, the male's tail. The net result is what The Architecture of Thought refers to as an "evolutionary arrow," a direction in the evolution of a species that may, or may not, be adaptive.
In most species, sexual selection operates on males so that selection is either by male-male conflict or by female sexual choice, with the result that phenotypic manifestations of selection are usually most apparent in the male. However, humans are unusual in forming long lived sexual pairs with dual parenting. A pair cannot form unless both partners make a choice so that, in humans, sexual selections are made by both males and females. The effect is that both men and women can exhibit sexually selected phenotypes, gender specific traits created by evolutionary arrows and arising from sexual selection. Each such trait should be matched by a corresponding sexuality in the other gender.
Social structure enters this discussion because the most evident and unique aspects of the human phenotype are culture and social structures. The implication of this discussion is that the physical and psychological traits that make human culture possible will have arisen through sexual selection. This implies further that the major features of the human phenotypes that enable human culture and society will have become mapped onto aspects of human sexuality. Therefore, we can argue and expect that the major, stable features of our extended phenotype, culture, will be mapped onto our sexual behaviors.
An important feature of evolution that can apply to social animals, such as humans, but not to nonsocial species, is group selection. If a species lives in groups, one group competes with another group and the biological fitness of an individual comes to depend, not just on his or her own qualities as an individual, but also on the fitness of the group of which they are a part. In a highly soical species, the main unit of selection may move from the individual to the group and The Architecture of Thought takes the group to be a major unit of selection in humans. It also holds that, in this group selection, the knowledge under direct selection is not genetic, level1 knowledge but social, level3 knowledge. Group selection will therefore alter a species' genetic endowment by altering its ability to handle and apply social knowledge.
Human groups have internal structure, a simple description being based on a hierarchy and some sort of class structure. For example, an army has a hierarchy of different ranks, from private up to general. In biology, all social species seem to have social structures based on hierarchy and, one presumes, hierarchically organized social groups are successful in competition with groups arranged in other ways. The different hierarchies of human groups indicates the presence of horizontal divisions within society, separating these different classes from one another.
However, the different ranks of a human society also display the existence of vertical divisions, especially among the lower ranks. Going back to an army as an example, these vertical divisions separate different soldierly specialisms, one group is artillery, another infantry, while soldiers on horseback are cavalry. In any social group, the vertical divisions separate subgroups who are playing different roles in the overall group.
Among the animal kingdom, all social species have some sort of hierarchy, and hence the horizontal divisions in their social structure but many do not exhibit obvious vertical divisions - for example, grazing animals have little subgroup structure. However, humans do and we can also be expected to display biological adaptations that fit us to struggle for and display our social status and, as Veblen observed, we are very anxious to display that status. We can also be expected to display adaptations thst fit us to take on one of the disparate social roles involved in subgroup formation and the vetical divisions in society. Successful social adaptation will, therefore, probablly arise both from adaptations to status and to subgroup formation. The latter involves different people having different characteristics, each being adapted to play different roles within a group. Hence, social adaptation in humans is likely to produce a population containing a heterogeneous mixture of social characteristics. In other words, human beings will all be different from one another, even though they are members of the same group.
If human populations are sexually selected and have a heterogeneous mixture of personality types and physical characteristics, then, as a sexually selected species, they must also be expected to display a heterogeneous mixture of sexualities. Human sexual heterogeneity arises from the phenotypic heterogeneity required by social groups. An analysis of human sexuality must, therefore, be linked to an analysis of social knowledge and social organization and to the role sexuality plays as a social glue in adult pair formation.
This is one the arguments on which the bioepistemic interpretation of human sexual "deviation" is based. Some elements of human sexual "deviation" arise because they are the sexualities needed to produce the heterogeneous mixture of phenotypes that constitute a successful group.
Humans sexuality, meaning what we would call "normal" heterosexuality, is not normal at all and quite different from that of other mammals. This modified heterosexuality is most visible in the unusual nature of human female sexual characteristics, such traits - permanent breasts, cryptic ovulation and the menopause are just three of the ways in which the sexual biology of human females differs from that of even our closest animal relatives. In general, these sexual traits seem to be designed to create social pairs between men and women, the roles of those pairs being to raise and educate human children. This parental pairing is an adaptation that serves the needs of social knowledge. Young humans need a long childhood to acquire social knowledge from their elders. Sexually paired parents are better able to provide this protection and education.
In later life, an older woman would not be able to raise any new offspring through the long human childhood, so an older woman's social efforts are better expended on helping with grandchildren. Hence, the menopause seems designed to create a population of grandmothers who will have a genuine biological role - to pass on knowledge of child care to their own daughters and help raise and educate their grandchildren. Insofar as our sexual adaptations encourage joint parenting, they make sex into a social glue that holds men and women together in social pairs, so producing the family units into which children are born and within which they are nurtured. The female sexual trait that seems most linked to this pair formation is cryptic ovulation, which forces men to form a permanent pair if they are to ensure their own paternity.
The above changes to human sexuality arise from social knowledge but there two other mechanisms by which social knowledge will have changed human sexuality. All our other, non-sexual traits that are linked to social knowledge, such as longevity, long childhood and facility with language, will be among the traits that arise from sexual selection and serve the needs of social knowledge. Given that our evolution is via sexual selection, we must have sexual preferences, in either male or female, to drive the development of the corresponding, social knowledge linked trait. For example, if we have a voice box to serve the needs of social knowledge, there must be some form of sexual selection for articulate people to have driven its development.
Finally, we note that humans are a phenotypically heterogeneous species. We look different from one another, grow to different sizes and have a variety of traits and abilities. Some of us are very clever, others very athletic, some are dominant leaders, some are submissive followers etc. This variability can be called phenotypic heterogeneity and it arises within group selection because it helps to create and populate the divisions in our social groups. Phenotypic heterogeneity means that a group of humans will have members who display a range of different skills and are naturally fitted to a variety of different roles. Thus the group may have some members who are good leaders and others who are natural followers, some will be good hunters and others skilled making the tools the hunters will need. Still more will have good brains, they will remember the past, connect cause with effect and be able to communicate their conclusions to other group members.
In sum, humans are phenotypically heterogeneous and this heterogeneity is an adaptation to the needs of the social groups that are associated with social knowledge. However, this phenotypic heterogeneity must have arisen through sexual selection, implying that not only is the human phenotype heterogeneous but so will be the sexualities that drive the production of this range of phenotypes. In other words, in a normal population of humans, different people should display different sexualities, each in its different way, reflecting the needs of social knowledge. It is this picture of sexuality that is capable of interpreting the "sexual deviations,"traits such as homosexuality and sadomasochism, that are such puzzling aspects of the human sexual makeup. Bioepsitemic evolution concludes that the main sexual deviations should map onto the structure of social knowledge and this is, indeed, the case. Please see the "other sexualities" page of this web site for a more detailed discussion.
Taking the idea of social knowledge as evolving much as do animals, it is natural to want to draw analogies between biological evolution and social evolution and compare the two evolutionary processes. There have been a number of such attempts, perhaps the best known being sociobiology and memetics. The present author feels that both these approaches suffer from a weakness, namely that they suppose genetics to be a prototypical or foundational base from which all other evolutionary processes can be modeled. In the opinion of this author, that supposition is wrong.
Sociobiology almost seeks to derive culture from genetics. However, it is in the nature of evolutionary theory that deriving testable predictions from it is difficult - evolutionary theory is good at interpreting observations but not very good at making predictions. Social systems are too far removed from genetics to derive predictions about their properties and trying to do so is a bit like trying to derive the workings of a steam engine from quantum mechanics - possible in principle but not sensible in practice.
Memetics has a different and more fundamental fault; it simply assumes that social knowledge will have the same structure or formatting as genetic knowledge, in other words that social knowledge will be packeted into memes, in the way genetic knowledge is packeted into genes. Actually, the author is aware of no serious evidence for data packeting in social knowledge - if readers know better, he would be grateful for information on the matter. The memetic assumption of data packeting seems to be simply an error and there is, in reality, no reason to think that the data packeting seen in genetics and biological evolution will be prototypical of evolution in general. There is no reason to postulate "memes" or to believe that they exist.
Genes are commonly called "fundamental replicators" but even that is a bit dubious since, in fact, they cannot replicate on their own. The smallest known replicator in biology is the cell. However, biological evolution is certainly based on genes, which are packets of data or atoms of biological evolution but the essential point is that the packeting of genes arises from biology and biochemistry, not from evolution. The reason biological information becomes "packaged" into genes is because, in biology, each gene must code for a complete protein molecule. A gene only functions correctly if the protein for which it codes is produced as a complete and functioning protein molecule. This constraint demands a strict sequence of DNA to perform the coding. If a gene codes for only part of a protein molecule then it is faulty and that gene codes for no biological activity. That is why genes behave as packets or atoms in evolution. However, these biochemical facts provide no ground for an analogy with social knowledge; in short, they provide no grounds for believing that social knowledge will be packeted into atoms of social evolution, into memes that somehow resemble genes. The argument just given undermines the foundations of memetics and the analogies it draws between social and genetic evolution. In the opinion of this author, the fundamental postulate of memetics, namely the notion of the "meme" as an indivisible unit of social information, is unlikely to have any reality and that ideas like "replicators" or "atoms of evolution" should be restricted to biology. (Even the meaning of such terms is unclear in biology, where, as mentioned, the smallest known "replicator" is the cell.)
Accordingly, the hierarchical picture of evolution developed in, "The Architecture of Thought," does not allow genes, memes or other replicators to be fundamental concepts. Instead, bioepistemic evolution advances data, information and knowledge as its fundamental concepts and develops its evolutionary framework from them.
"The Architecture of Thought" develops an analytical formalism in which data is interpreted into information and the information is then selected from to produce knowledge. In evolving systems, these processes of interpretation and selection require data flows to take place inside each evolving system. The data flow model of evolution involves describing the pattern of these data flows. This approach to describing evolution is applicable not just to organisms but also to other evolving systems, such as cultures. Hence, the data flow model enables the main features of biological and cultural evolution to be directly compared.
So, for example, in biological evolving systems the main data flows occur from DNA, to RNA to protein and arise from transcription and translation. These data flows can be compared with those in social evolving systems where the data flows arise from learning and education and from political activities. Through the political comparison, bioepistemic evolution and the data flow model identify elites as the social entities analogous to the germ lines of biological evolution.
Data flow also allows one to understand the importance of the division of labour - the way in which different people come to play different social roles. The data flow model has implications for general human nature and the sexual selection processes that lead to different individuals being fitted to their disparate social roles can be seen is part of the process that creates sexual deviation. The same argument also enables one to interpret aspects of human psychology - for example, the structure of irrationality can be seen as arising from the different roles people play as actors in the evolving system of culture. However, we will leave the matter there.
© John A. Hewitt. This is the social structure page from part of the site sexandphilosophy.co.uk and is very abbreviated from material in the book The Architecture of Thought.
Last Updated, 22 November 2005