VariKin Findings: Frequently-used kinship terms evolve slowly

VariKin Findings: Frequently-used kinship terms evolve slowly

— by Maisie Ford

Language is constantly changing. As new words are born or enter a language, old words fall out of use. Linguists have known for a long time that some words endure longer than others. Some core vocabulary, like numbers, names of common animals/plants, and words for parts of the body can be thousands of years old and still in use. This intuition was put to the test by Mark Pagel, Quentin Atkinson, and Andrew Meade in their 2007 paper, Frequency of word-use predicts rates of lexical evolution throughout Indo-European history. Using language corpora (large collections of transcribed speech or collected text), and phylogenetic comparative methods, they found that more frequently used words from the core vocabulary are replaced at a slower rate in European languages.

Image credit: Altrincham Adventures in Art

But why is this? Do often-used words leave a stronger imprint in our minds and are therefore less likely to be lost? Or is it that large scale conceptual or social changes relating to how we think and talk about the world around us are more likely to displace words that are used less often?

VariKin team members Péter Rácz and Sam Passmore (lead authors), Catherine Sheard and Fiona Jordan explored this very question with kinship words in their open-access paper, “Usage frequency and lexical class determine the evolution of kinship terms in Indo-European”, published in Royal Society Open Science in October 2019.

Péter collected large-scale language corpora across 47 Indo-European languages, so as to determine the frequency of use of terms for family and kin. Using phylogenetic comparative methods, Sam modelled how fast kinship words are replaced in these languages. Kinship terms are not just single linguistic labels for individuals, because multiple relatives can be called by the same term such as “cousin” in English, or “tante” (aunt, in French). Kin terms form systems, and multiple terms shift together when one system is replaced with another one through social or cultural changes. VariKin team members explore this aspect in some of their other papers:

Image credit: Altrincham Adventures in Art

In the present paper, the team found that, as with core vocabulary, the most frequently used kinship terms are replaced more slowly over time. In fact, the relationship between rate of replacement and frequency of use was found to be even stronger in kinship terminology than in core vocabulary in general. This is hypothesised to be due to the fact that kinship words, in every language, constitute a closed lexical class, which suggests that the reason more frequent words are more resilient is not that they are more memorable. Rather it is that they are less likely to be affected by complex conceptual changes in language. Terms for ‘mother’ or ‘father’ last for thousands of years!

The findings shed further light on how language change is related to language use.  It also adds to what we know about the ways in which evolutionary parallels exist in biology and culture (we know that genes involved in multiple functions change more slowly), and informs debates on dynamics of change in linguistics and complex systems theory in general.

Watch this space for an interview coming soon with Péter Rácz and Sam Passmore in which we discuss this paper further. We will be posting these summaries of papers from the VariKin project over the next few months as the project winds up.

on classification [scrapbook]

Darwin, in The Descent of Man

Every naturalist who has had the misfortune to undertake the description of a group of highly varying organisms, has encountered cases (I speak after experience) precisely like that of man; and if of a cautious disposition, he will end by uniting all the forms which graduate into each other as a single species; for he will say to himself that he has no right to give names to objects which he cannot define.

1871, 1st ed. vol 1, p. 226-7

definitions of evolution [scrapbook]

Evolution is not changes in gene frequencies. Genes are part of a network of developmental causes that lead to the manifestation of traits that have general properties in common across individuals while retaining individual differences. Evolution is change in the frequencies of alternative developmental causes that yield variations in developmental trajectories (a phrase that is more cumbersome than ‘‘changes in gene frequencies’’ but nevertheless more correct).

Source: Michel, GF and Tyler, AN. Developing human nature:“Development to” versus “Development from?”. Developmental Psychobiology (2007) vol. 49 (8) pp. 788-799  DOI: 10.1002/dev.20261

on sex and suicide bombing

Please note this post was edited (below) on 23 May 2011

David Lawson, Kesson Magid and I have just published On Sex and Suicide Bombing: An evaluation of Kanazawa’s ‘Evolutionary Psychological Imagination’. This is a critique of Satoshi Kanazawa’s 2007 paper: “The Evolutionary Psychological Imagination: Why You Can’t Get a Date on a Saturday Night and Why Most Suicide Bombers are Muslim.”

Many objections to evolutionary psychology are ideological or political. This is not the case in our paper: nothing makes me (and my co-authors) froth at the mouth more than bad science. We say:

The beauty of the scientific method is that it allows us to ask, and sometimes answer, tough questions.
Addressing the tough questions without the transparency afforded by the scientific method is not brave: it is simply cavalier.

Kanazawa’s paper is full of bad science. We are not the first to criticise him on such grounds, but it bears repeating that when there are controversial and sensitive issues at stake, we beholden to demand a high standard of scholarship and science.

EDIT 23 May 2011

In the light of another piece of “science” by Kanazawa, reported on his blog, I have decided to add to this post a list of the published academic responses to Kanazawa’s work. It really saddens me that someone who pushes an agenda to carry out controversial investigations cannot pair that agenda with quality science. As said above, with academic freedom comes responsibility.

This list was compiled with the help of colleagues. Please let me know of any additions or corrections. At last count, the 20 listed papers involved 56 separate authors.

Continue reading →

blue is not better than white, and metaphor is unhelpful

The blue-beats-white winning bias in judo as reported in 2006 appears to have been confounded by a number of factors, and there is no bias after all. So say Dijkstra & Preenen in Proceedings B:

A study by Rowe et al. reported a winning bias for judo athletes wearing a blue outfit relative to those wearing a white one during the 2004 Olympics. It was suggested that blue is associated with a higher likelihood of winning through differential effects of colour on opponent visibility and/or an intimidating effect on the opponent. However, we argue that there is no colour effect on winning in judo. We show that alternative factors, namely allocation biases, asymmetries in prior experience and differences in recovery time are possible confounding factors in the analysis of Rowe et al. After controlling for these factors, we found no difference in blue and white wins. We further analysed contest outcomes of 71 other major judo tournaments and also found no winning bias. Our findings have implications for sports policy makers: they suggest that a white–blue outfit pairing ensures an equal level of play.

I love negative results. They’re a complete bummer if it was your darling positive result in the first place, but they provide the clearest demonstration of how science works. The red-wins bias reported in 2006 appears to be still (pardon the pun) in play!

From the realms of philosophy of biology, an interesting article by Bjorn Brunnander about intentional language in evolutionary discourse. Is the trade-off between the efficiency-and-power of metaphorical shorthand, and the misconceptions it produces (the never-ending of conflation of proximate and ultimate), actually producing more problems than it solves?

Many evolutionists today argue for the need to make evolutionary theory an integrated part of psychology and the social sciences. If this is the agenda it should be in the interests of these thinkers to worry about factors that affect the probability of successful communication across boundaries. The track record of communication of evolutionary thinking is not altogether impressive. This is commonly recognised by evolutionists themselves, as shown by presentations of ‘popular misunderstandings’. The fact that some recurring misconceptions are clearly what we would expect to find if processing of the intentional shorthand was unreliable should make us lift questions about efficiency of exposition above the realm of rather effortless rationalisation.

Is the language of intentional psychology an efficient tool for evolutionists?(doi)

a rather disheartening game of bingo

Backlash isn’t really the right word.

Evolutionary Psychology Bingo.

I fully expect to see this linked-to, emailed, and generally be the object of a bit of discussion online. On the one hand, I’m all for the satirisation of poor science (a more biting example appeared last week), especially poor science that uses the tools (evolutionary thinking) that I do. We must, after all, stringently promote the self-correcting aspect of the scientific method. And there is some poor “evolutionary psychology” research around.

On the other hand: seeing that bingo card just makes my stomach sink into the floor.

There are plenty of people who are attempting to rehabilitate the term “evolutionary psychology” into an umbrella concept covering all research in the human evolutionary behavioural sciences (EP is much shorter and catchier, for one thing). This encompasses things like evolutionary economics, behavioural ecology, cultural evolution, evolutionary archaeology, etc, i.e. things that I do.

I am not actually in favour of this rehabilitation anymore. A couple of years ago I was, but I do think that the public perception of evolutionary psychology as catastrophically simplistic, sexist, privileged and daft is (sadly) firmly entrenched. We (the academic we) might be able to rehabilitate it within academic circles, but it is badly damaged in public discourse.

I’m not wanting to discuss in detail why EP has a bad name, as that’s a really nuanced and important set of problems that I can’t do justice to today. Part of it is poor science, sure. But there is poor science everywhere, just like there is poor customer service, poor computer hardware, and poor music in the Top 40: all examples where is supposedly a quality filter somewhere along the line. Part of it is bad science reporting. Evolution is a technical subject, and terms such as “nature”, “culture”, and “development” do not have the same meanings to people reading a news report as they do to people writing a research paper. It is also a subject dealing with trends and probabilities and on-averages: not with predictions about individual behaviour.

That last point cannot be stressed enough, as some of the cells in the bingo card seem to stem from a mis-reading from the population level to the individual. For example:

“I can rotate three-dimensional objects in my mind and you can’t.”

If I remember second-year perceptual psychology well enough, men are, on average, better at mental rotation tasks than women are. There are population bell-curves of ability, and they overlap a lot, but the mean of men’s mental rotation ability is some value higher than the mean value of women’s. This does not mean men can and women can’t. This does not mean an individual man will always do better than a woman.

These subtleties are really. Really. Important. And seeing the bingo card does not give me hope that these subtleties have been or can be communicated easily. I think it is the responsibility of scientists to communicate the exact nature of those important messages to journalists and the public. I also think that journalists and the public have a responsibility to want to hear them and not dismiss them as “quibbles” or “difficult statistics”, and simply latch on to the sensational. Especially if it is controversial, as is the case with gender issues.

I can’t cover everything in one blog post, but the other thing that saddens me about the bingo card is the conflation of “evolutionary” with “natural”, “genetic”, “permanent”, and “unchangeable”. A lot of very smart people (Patrick Bateson springs to mind) have written about how this conflation is central to the wearisome “nature-nurture debate”, but this has also not been communicated well beyond academic journals.

I’m not sure how to remedy this. I don’t feel I have any new insights, but perhaps I should start on a couple of posts detailing the ways in which the term “human nature” should be employed with utmost caution. Not because it doesn’t exist, but because we all need to know what exactly we’re referring to.

Anyhow, satire is always useful for stimulating debate. At the very least it’s a clever discussion aid for a seminar on evolutionary psychology.

evolution 2007

Radio silence for the last couple of weeks as I was in New Zealand at the Evolution 2007 meeting. Yes, there is internet access on my small island home, but I’m not one of those superstars who can multitask a big conference and blogging. So before it all dribbles out of my brain, here’s a brief rundown. [link to program pdf]

Russell Gray and I organised a symposium on Cultural Phylogenetics. There are pictures, but they will have to wait another day.

Our speakers (Mark Pagel, Michael Dunn, Simon Greenhill, Quentin Atkinson, Russell, and myself) spoke on different aspects of applying phylogenetic and comparative methods to interesting and cool questions in linguistics and anthropology. Click on the picture for an overview of the talks.


Given that it was early on a Sunday morning we had a great turnout (80-120 people) over the three hours. Really fabulous to have the hardcore evolutionary biologists come along to see some novel applications of “their” methods, and it seemed to be well-received!

The conference had about 900 people in attendance with up to eight simultaneous sessions going on for the four full days, so it was hectic running about from room to room to catch talks. Luckily most of what I wanted to hear was fairly systematically (haha) grouped, so I got to attend a number of talks on phylogenetic theory and methods, behavioural/social evolution, sexual selection, coevolution, and teaching evolution. The last day also had a great session on molecular anthropology, most of which was concentrated on questions about Pacific dispersals and human migrations.

Conferences really are great for making your brain swim 24/7 in a soup of ideas, whether they’re directly related to your work or not. It’s simply stimulating being around loads of other people who like to ask questions and think of clever ways to answer them.

While I was away I read Evolutionary Pathways in Nature: A Phylogenetic Approach by John Avise. It’s a collection of short essays that tackle questions about different critters, from spider-web building to the tracking of the AIDS virus in humans. What they have in common is that moledular phylogenies have been used to help with the detective work. It was a fun book to dip into (it’s the book the ultra-geeky biologist has in the loo), but the theme was only a thin thread on which to peg the various stories. Although the Introduction and Appendix gave a little background to phylogenetics and molecular systematics, a complete newcomer would no doubt be confused. Sadly (or perhaps not…) I think the popular science book on phylogenetics remains to be written.

the two cultures revisited (ad nauseum)

A short while ago I attended one of a series of talks set up to create some dialogue between evolutionary and interpretive approaches in archaeology. I was only able to attend the last of the series, but others who attended earlier talks reported that the presentations themselves (one from each of the two “styles”) were interesting and informative, but that the discussions that took place afterwards, where, ostensibly, the dialogue was to get into full swing, were quite fraught, full of misunderstandings and tense “science versus post-modernism” exchanges.

Which is, as always, a shame. I think to most scientifically-minded archaeologists and anthropologists–indeed anyone in the social sciences who appreciates the scientific method–the lack of useful dialogue, collaboration, and proper communication with our colleagues who have other approaches is felt as a keen deficit. From afar, we can observe the wealth of rich material (dare I say “data”?) collected by social anthropologists (for instance). More importantly, we can observe their ability to contextualise, interpret and suggest new or alternative hypotheses for what we, with the necessity of abstract or simple models, are sometimes missing in our approaches.

However, after attending the last talk, I don’t think that they (“they” being in this case those in the social sciences who probably prefer the term humanities) really feel any keen need for such dialogue in the other direction. I could be (and would be delighted to be) very wrong about this. I got the sense of a lamentable misunderstanding how science as applied to human affairs. Misunderstanding the scientific method is of course a more general malady, from the sub-editors at the Evening Standard right on through to nutritionists with dodgy qualifications.

But at this talk there were some SHOCKERS. Continue reading →

please leave a msg, the aliens are on myspace

Geoffrey Miller writes in SEED Magazine about Why We Haven't Met Any Aliens.

Basically, I think the aliens don't blow themselves up; they just get addicted to computer games. They forget to send radio signals or colonize space because they're too busy with runaway consumerism and virtual-reality narcissism. They don't need Sentinels to enslave them in a Matrix; they do it to themselves, just as we are doing today. Once they turn inwards to chase their shiny pennies of pleasure, they lose the cosmic plot.

According to GM, the best and brightest minds get seduced by fancy entertainment technologies that mimic our evolutionary go-to impulses: fast-food, porn, iPods. There'll be no-one left to run NASA, and maybe–like the aliens–there'll just be no-one left.

Uh, I don't think so. As a bright spark in our discussion group said, Miller deflates his own argument later on:

Some individuals and families may start with an "irrational" Luddite abhorrence of entertainment technology, and they may evolve ever more self-control, conscientiousness and pragmatism.

That is, natural variation will contain strategies that will outcompete the Sims-addicted entertainment-happy phenotypes. This happens to me all the time because other people read journal articles when I read Batman. 

It's provoking, this piece, and I suspect not entirely serious–although the last remarks concerning the rise of  fundamentalism(s) need to be unpacked with respect to evolutionary motivations ALSO. I do like the term "creative class", but it irks me because it comes from a place of privilege. Someone's gotta be out there running the hamster wheel that makes the internet go. Someone's soldering the chip in your VR goggles. And that someone will quite likely be more than motivated to take your place in the great quest for knowledge if you're just slouched on the couch.