Genetics and Sociology

I was googling terms related to social science and genetics, and I happened on TCD’s research website, where they have a theme for “Genetics and Society“, selling their research in the area. Mostly anodyne boosterism but I tripped up at what they had to say about sociology:

In Trinity, multi-disciplinary teams work together to address key questions;


In Sociology: how will individuals and society benefit from this information?

Such weak sauce. They obviously didn’t talk to any knowledgeable sociologists.

It triggered a rant (though to be fair, about points I’d been thinking about already, relative to the relationship between the social sciences and the new biology, so this isn’t all really at TCD’s expense).

First, it wouldn’t be “benefits”, it’d be risks and benefits. Sociology will look this up and down and then pronounce. Mentioning “risks” in promotional material is likely unwelcome (“everything we do is good!”), but sociology would exactly focus on the potential down- as well as upside. More diplomatically you could perhaps say “the risks and benefits, with a view to minimising the former and maximising the latter”.

But that would only one angle sociology would take, focusing on ethics, the impact of technology, and Science and Technology Studies. The main sociological take should be as follows: Finally, we’re getting more or less reliable and broad-based estimates of the role of genetics in determining outcomes that are socially and behaviourally relevant: how can we use this to better assess the competing and interacting effects of social and biological causes in the determination of social inequality, of social and behavioural outcomes? That is, how do we use more reliable claims about biology (often more modest than the wilder assertions of the past) to better understand society?

But that not’s all: sociology is a population science, and population structure is latterly (quite well now but initially with reluctance) being recognised as a major dimension of the interaction of environment and genetics in determining a wide range of outcomes. In a simple sense, population structure is a problem because in the population there is a complex relationship between genes and environment. This is due to all sorts of processes of population sorting, in combination with genetic variation driven by drift or selection. Some of this is simple geography: populations in one place tend to be related and to have a great deal of shared environment. This is why a GWAS on one population might fail to generalise to another: there’s some sort of genetic stratification in the first population which is associated with environmental factors relevant to the outcome of interest, whereas in the second you might have the same genetic variety and range of environment but distributed differently. I understand that there are very clever statistical workarounds to deal with this, but that their efficacy is still contested.

But population stratification can and should be regarded as a topic of research in its own right, and here sociology (and geography, history, anthropology, archaeology and so on) can help. History of population movements, processes of residential and social segregation, social inequality and stratification, and a host of other “legible” phenomena lie behind this and there is really a signficant opportunity for dialogue between genetic and social sciences (it’s already going on but not everyone sees it).

One key form of “population structure” that catches my attention (because I’ve done a lot of research in the area in the past) is assortative mating. This emerges in genetics as a tweak in the simple model of inheritance where siblings have 50% similarity: in reality the figure will be higher if the parents have more than background levels of similarity, and an assortative mating parameter is use to account for that. There’s a natural tendency for every discipline to at least attempt to explain everything in its own terms, but sometimes it’s just better to interact with colleagues outside. I’ve seen more than one paper where the suggestion of AM leads biologists to speculate about how we are genetically determined to seek out partners who are genetically similar to us; as a sociologist I wouldn’t a priori exclude the possibility, but wow, there are a lot of other processes I’d look at first. Geography first of all: in populations that haven’t been very mobile, your neighbours will be more similar to you than people further away (and you’ll find a mate locally). Then there is so much existing sociological and anthropological research annotating and analysing other systematic mechanisms of assortative mating: religious endogamy, ethnic group endogamy, social class, social status, educational, everything from traditional match-making to Tinder, and so on. This sort of research theorises, and documents in detail, how AM arises for both socio-structural and normative reasons (or we could go with the economists, who see AM as arising not for structural or normative reasons, but out of competition for the mate with the best earning potential).

That is, while genetics can inform sociology (and sociologist co-researchers would clearly help avoid some of the more naive genetic determinism that is appearing about social outcomes), sociology, the social sciences in general, can help inform population genetics.

In other words, and not to bash Trinity too much, there is far more to it than genetics as a gift on a silver platter, handed down so we can ask “how will individuals and society benefit from this information?”.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.