In this 'dark age' of intense political and ideological contestation, it's inevitable that some people should express (again) a strong desire for universal ’truth’ in social and political life. Genuine ideologues are immune to such concerns: for us, discourses create narratives for our moral instincts and power is the explanatory variable which mediates between ideas and reality.

Centrists also have moral intuitions but often appear to lack confidence that the narrative justifications for their instincts provide sufficient epistemological certainty. Such 'skeptics' dismiss ideology as a social contruct unsuitable for ethical inquiry, but often end up replacing it with appeals to authority and nature in the form of scientism or 'realism'. Not all centrists are skeptics in this definition: many are ideological utilitarians who believe they can calculate optimum social outcomes. But in philosophical terms, the so-called skeptics argue that certain kinds of intuitions (i.e. their own) have ethical consequences because they can be demonstrated scientifically. 

This appeal to the empirical comes at a potentially dangerous time for the infant sciences of evolutionary sociology and psychology. For the first time, the social and biological sciences can offer coherent accounts of the origins and evolution of human culture. While the default philosophical position is that natural facts do not create moral ones, this distinction may be break down when culture is (correctly) understood as part of, rather than distinct from, the natural world. And it should worry the left that right-leaning centrists have noticed and begun to mis-apply cultural evolution to discredit and devalue other positions. To my mind, such people oversimplify the complex implications of cultural evolutionary theory, and in particular the idea of gene-culture co-evolution. This blog attempts to correct those misconceptions, and it does so using a device I'm rather fond of: the colour analogy. 

The colour analogy

The electromagetic spectrum is continuous and infinite; light can possess almost any wavelength and no wavelength is particularly differentiated from any other. Out of this infinite variety, we can think of the visible spectrum as those wavelengths which convery potentially useful information on a planet like Earth, which is composed of certain elements at certain temperatures. What this implies is that it's useful for agents to know, for example, that most plants are 'green'; but linguistic colour categories ike red, blue and green are arbitrary linguistic constructs with no basis in physics. Firstly, since wavelengths are continuous, where we draw dividing lines between categories is completely random (or so it seems). And secondly, we have no way of guaranteeing that two agents see a colour distinction in the same place. We can agree that a plant is the same colour, but experience that colour in relation to others completely differently.

For the sake of the further analogy, consider light's wavelength a natural, scientific fact and subjective categorisation of that colour (a cultural construct) as their social construction of its meaning. 

For a long time in the twentieth century, this insight was the central underpinning of the Sapir-Whorf hypothesis: the idea that language categories were essentially arbitrary, and moreover these arbitrary categorical differences altered how individuals perceived the world. Anthropologists showed how different cultures described and experience colour in vastly different ways, and historians also noted the relatively paucity of words and concepts describing colour in the ancient world. This was a view of culture and language at home with the then-dominant 'blank slate' thesis of human psychology and the strict separation enforced between biology and culture in the aftermath of the discrediting of Social Darwinism. 

Yet in 1969 (and in continuing work since), Berlin & Kay showed that there was an underlying pattern to all this diversity. Colour terms did not emerge randomly, but appeared to follow patterns that the researchers believed corresponded with economic and social development. First, a society distinguished between light and dark, then red, then yellow and green, then blue, then brown, and finally orange, purple and grey. There were exceptions within this pattern, of course: some variation caused by randomness, others by specific adaption to particular ecologies. But on the whole, Berlin & Key had discovered that colour terms evolved in a common way amongst humans, suggesting an underlying structural pattern. The following explainer from Vox does the topic some justice:

In fact, this universality amongst the human experience of colour may be hard-wired into our biology. Like all Old World primates, but unlike most mammals, humans are trichomats - with three types of colour receptors in our visual system attuned to short- (blue), medium (green), and long- (yellow-red) wavelengths. It would uncontroversial to assert that the particular combination of visual receptors found in our biology are the product of adaption to the natural environment through natural selection: being a trichromat at these wavelengths conveys an evolutionary advantage (in the form of electromagnetic data) at acceptable cost. Similarly, it should be uncontroversial to state that the way we use and analyse that data socially is subject to selection effects based on whether our categorisations of colour convey socially and environmentally useful information at acceptable cost. 

Gene-culture coevolution contains both these premises, but also something extra: the types of colour category that can emerge culturally are constrained by our common biological inheritance (and vice-versa). In other words, cultural variation and adaption is not infinite, but shaped by genetic factors common to all homo sapiens - cultural evolution is path dependent and part of that path is a universal biological inheritance. Any human society, pre-loaded with red, green and blue colour visual receptors and operating in an Earth-like natural environment will develop colour terms in a (relatively) predictable fashion depending on its level of social complexity. The same is true of all culture: tolerable variations in behaviour must be suited to a bipedal, social animal with consistent biological needs such as food, water and shelter.

Sex and Gender

Let's consider what these insights mean for social policy, choosing an example with clear biological and cultural elements. Opponents of so-called 'gender ideology', a.k.a. the completely obvious conclusion that sex and gender are different things and gender is socially constructed, argue that biological categoriesof sex create an inarguable moral case against culturally recognising non-binary genders. Yet sex, like light wavelength, is not a strictly binominal category: biological sex is made up of a number of different indicators (i.e. reproductive role, secondary sexual characteristics etc) each of which in turn encloses some degree of variation. When these variances are given weights and summed for a species like humans that reproduces sexually, we would likely see two clusters of sexual characteristics with distinct statistical peaks but some variation and potential for overlap. Not a binary, but bimodal. 

Scientists can treat these clusters of biological averages as distinct 'sexes', and we can think of our day-to-day ability to distinguish between them our 'sex receptors'. While gender roles are a social construct, evidence that even very young children are sensitive to sex differences in adults suggests that there is at least some part of our developmental biology that is tuned to probabilistically distinguish sex categories. Thus, most (but far from all) human societies have developed binary gender roles because the cultural evolution of gender is influenced (but not dictated) by sexual dimorphism. But what's important is that there is clearly no barrier to recognising additional gender(role)s or different ones or none altogether - plenty of cultures have done so.  As societies become more open and tolerant of individual self-expression and definition, we can and should re-examine our existing social categories of gender and be more tolerant of categorical innovation. This really isn't that hard! 

Moral Colours

So let's bring this back to moral philosophy. I've mentioned Jon Haidt, his Moral Foundations Theory, and my problems with both him and it before. Haidt is becoming something of a guru to centre-rightists and 'classical liberals', but I feel this is because he has drawn the wrong ethical conclusions from his own research (a risk for any scientist). To summarize briefly, Haidt and his collaborators posit that humans are equipped with modular cognitive capabilities relating to ethical and social reasoning. The most well-studied of which are our aversion to physical harm (i.e. 'care'); our biases towards fair outcomes (or 'proportionality'); mechanisms for resolving stresses caused by social hierarchy (i.e. 'loyalty'); a slider for resolving the Omninove's Dilemma (i.e. 'openness to experience'); and a sensor to avoid potentially harmful substances (disgust or 'sanctity'). All of these biological modules make sense for a social species operating in a potentially hostile environment, and can be demonstrated in human populations of all levels of social organisation. 

Where Santa Barbara-style evolutionary psychologists, Haidt and their respective followers go wrong, however, is to leap immediately from these universal biological constraints to ethical rules, without considering culture or evolutionary history as intermediary variables. They believe, like sex-essentialists, that science has provided them with universal and objective 'truths' that can and should form the basis for universal ethical philosophy. Because Popperian science provides standards of falsifiability and objectivity, they believe their ethical conclusions are superior to conventional philosophy and ideologies. But all they have done is cloak their naive intuitionism with a naturalist fallacy.

The correct response to such claims is not to keep human culture and ethics separate from biology, but to understand that biological and cultural evolution both partially (and validly) contribute to social norms and practices. In other words, we can accept Haidt's claim that certain moral instincts (with both genetic and environment-driven variability) are universal to the human species. But we must also recognise that these merely weight the sorts of cultural systems humans can develop and do not determine them. In philosophical terms, our evolved intuitions may provide a useful short-hand way of resolving simple ethical questions, but complex societies require more complex and nuanced rules. Cultural rules and norms must always contend with these intuitions and biases (as the behaviourial economists believe), but they work together as often as against one another. Whether genes and culture are complementary or antagonistic depends on the types of social problem a society is trying to solve. 

As is common with sorts of enquiry, it turns out that complex philosophical and ethical problems don't actually have simple solutions. Reasonable people can and will disagree about what the categories of 'right' and 'wrong' include, in much the same way as we might disagree on distinguishing 'purple', 'magenta' and 'mauve'. While evolutionary science may be putting the intuitive case on firmer foundations, a full appreciation of cultural evolution must also recognise and knowledge that ideologies and culture are no less adapted to solving the sorts of social problems we face as a society.