Category Archives: Uncategorized


Tone and humidity

Does the weather effect the languages we speak?

This week, Caleb Everett, Damian Blasi and I have a paper out in PNAS (also available here) on the effects of humidity on the production and perception of lexical tone, and the subsequent predictions about the distribution of tone across the world.

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Map of humidity (lighter = more humid) with complex tone languages in red and non-complex tone languages in blue.

The basic principle behind studies of cultural evolution is that a selective pressure on communication can transform the structures of a language over time.  What we explore is whether speaking in dry environments exerts a pressure to avoid using sounds that are more difficult to produce or comprehend, leading to those sounds being selected against.

Edit: See also this FAQ page

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Issues in Cultural Evolution 2.1: Micro Evolution, Dawkins and Memes

It’s time I get back to my attempt to lay out a map of approaches to cultural evolution in a limited number of posts, say a half dozen or even less (in my first post I said three). This is the first of two or three posts in which I look at ideas of the microscale entities and processes. In this post I’ll take a close look at Dawkins’ concept of the meme as he laid it out in The Selfish Gene. In my next post or two I’ll lay out other positions while developing mine in the process.

Dawkins Defines the Meme

I’m going to take a close look at two paragraphs from the 30th Anniversary edition of The Selfish Gene (Oxford 2006). First I’ll quote the paragraphs without interruption and commentary. Then I’ll repeat them, this time inserting my own comments after passages from Dawkins.

The book, of course, is not primarily about culture. It is about biology and argues a gene-centric view of evolution. In the process Dawkins abstracts from the biology and extracts two roles, that of replicator and that of vehicle. Genes play the replicator role and phenotypes play vehicle role. From a gene-centric point of view, the function of phenotypes is to carry genes from one generation to the next.

Have set this out in ten chapters, Dawkins then turns to culture in the eleventh chapter, where he introduces the meme in the replicator role in cultural evolution. The paragraphs we’re examining are on pages 192-193:

Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation. If a scientist hears, or reads about, a good idea, he passes it on to his colleagues and students. He mentions it in his articles and his lectures. If the idea catches on, it can be said to propagate itself, spreading from brain to brain. As my colleague N. K. Humphrey neatly summed up an earlier draft of this chapter:’… memes should be regarded as living structures, not just metaphorically but technically. When you plant a fertile meme in my mind you literally parasitize my brain, turning it into a vehicle for the meme’s propagation in just the way that a virus may parasitize the genetic mechanism of a host cell. And this isn’t just a way of talking—the meme for, say, “belief in life after death” is actually realized physically, millions of times over, as a structure in the nervous systems of individual men the world over.’

Consider the idea of God. We do not know how it arose in the meme pool. Probably it originated many times by independent ‘mutation’. In any case, it is very old indeed. How does it replicate itself? By the spoken and written word, aided by great music and great art. Why does it have such high survival value? Remember that ‘survival value’ here does not mean value for a gene in a gene pool, but value for a meme in a meme pool. The question really means: What is it about the idea of a god that gives it its stability and penetrance in the cultural environment? The survival value of the god meme in the meme pool results from its great psychological appeal. It provides a superficially plausible answer to deep and troubling questions about existence. It suggests that injustices in this world may be rectified in the next. The ‘everlasting arms’ hold out a cushion against our own inadequacies which, like a doctor’s placebo, is none the less effective for being imaginary. These are some of the reasons why the idea of God is copied so readily by successive generations of individual brains. God exists, if only in the form of a meme with high survival value, or infective power, in the environment provided by human culture.

Dawkins says more about memes (the chapter runs from 189 to 201), but I’ll confine my commentary to those two chapters. Before I do that, however, I’d like to quote two short paragraphs from the end of the chapter (pp. 199-200):

However speculative my development of the theory of memes may be, there is one serious point which I would like to emphasize once again. This is that when we look at the evolution of cultural traits and at their survival value, we must be clear whose survival we are talking about. Biologists, as we have seen, are accustomed to looking for advantages at the gene level (or the individual, the group, or the species level according to taste). What we have not previously considered is that a cultural trait may have evolved in the way that it has, simply because it is advantageous to itself.

We do not have to look for conventional biological survival values of traits like religion, music, and ritual dancing, though these may also be present. Once the genes have provided their survival machines with brains that are capable of rapid imitation, the memes will automatically take over. We do not even have to posit a genetic advantage in imitation, though that would certainly help. All that is necessary is that the brain should be capable of imitation: memes will then evolve that exploit the capability to the full.

That I believe is the core of Dawkins’ contribution, that the entity that directly benefits from cultural evolution is some cultural entity, not any individual human being, though the cultural entity is necessarily dependent on individual humans for its existence. Continue reading


Tokyo Lectures in Language Evolution

This will certainly be of interest to rep typo readers. Info below:

We are pleased to announce that the Tokyo Lectures in Language Evolution will be held from the 2nd – 5th of April 2015 at the Komaba II Campus of the University of Tokyo. The event will bring together researchers from around the world to give an intensive series of courses and lectures introducing modern approaches to research on the origins and evolution of language.

Invited Speakers:

Registration Fees:

  • Faculty:        20,000JPY
  • Students:     Free

Please note, there are limited seats available so please register here to ensure your place.

Poster Session:

The event will host a poster session for participants to present their own work. Submission instructions are available here.

Key Points:

Dates:                         2-5 April 2015
Poster Call Deadline:  4 March 2015
Location:                     Tokyo, Japan
Any enquiries regarding the event should be directed to

We hope to see you in Tokyo!

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Serotonin and short-term/long-term orientation

This week I discovered that an analysis using Causal Graphs that James and I did in 2013 has been backed up by more recent data.  This demonstrates the power of Causal Graph analysis, which we’ll be discussing in our workshop on Causality in the Language Sciences (submission deadline extended!)

A recent paper demonstrates a correlation between various genetic factors and life history strategies (Minkov & Bond, 2015).  Minkov & Bond find that the prevalence of three gene polymorphisms (5-HTTLPR serotonin transporter gene, the androgen receptor gene AR and the dopamine receptor gene DRD4) correlate with measures of how willing people are to take risks, such as long-term/short-term orientation.

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We’re written before about 5-HTTLPR (here and here), which was previously associated with individualism/collectivism.  However, the paper above, and a previous one in 2014 by Minkov, Blagoev & Bond, find that the correlation is stronger for long-term/short-term orientation.

What’s interesting for us is that James and I predicted this in our 2013 paper on spurious correlations (the one with acacia trees and traffic accidents).  Here’s figure 4 from our paper, which was generated using a causal graph algoritm (explained in more detail in this post):

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The relevant part is here, which predicts that 5-HTTLPR prevalence is causally related to Long-term/short-term orientation, but is causally independent from collectivism:

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We suggested that the relationship between 5-HTTLPR and collectivism is mediated by the probability of migrating into harsher climates (a kind of risk-taking), and produced a computational model to demonstrate the principle (we also did some analyses which showed that measures of climate are correlated with 5-HTTLPR, but we haven’t reported these).

The more recent papers above also suggest that the genetic traits are linked with long-term/short-term orientation, but did so my greatly expanding the sample of genetic prevalence.  So how did we get our result?  In our analysis, we averaged 5-HTTLPR prevalence across countries, which is not realistic.  This makes me worried that the correlations are being inflated by non-independence of the samples.

The authors are confident of the robustness of the correlation:

“If all these associations were spurious, their association would be miraculous, especially at the national-regional level. If there is no real association between the LHSGF and the reported measures of LHS and TO, what then explains the extremely high correlations?”

However, as our paper argues, spurious correlations are more likely when datapoints are linked through historical descent or borrowing (Galton’s problem).  In the case of this paper, genetic traits are obviously historically related, and it’s likely that cultural values and life history strategies are also culturally transmitted.

I tried testing whether the correlation is robust to historical or contact relationships.  I used geographic proximity as a proxy for how closely related different cultures are.  For each country, I found the geographic coordinates of the capital city.  The graphs below demonstrate that there’s at least some geographic clustering (and a hit of a founder effect for the genetic data, as predicted by our migration model):

Geographic distribution of the genetic index

Geographic distribution of the genetic index

Geographic distribution of the life history strategy index

Geographic distribution of the life history strategy index

I then calculated the distance between each pair of countries in geographic terms (great circle distance), the National life history strategy genetic factor index and the genetic factors.  (for the genetic factors, I did a principal components analysis, as in Mikov & Bond, and used the first component, which had an eigen value of 2.62 and explained  65.5% of the variance, compared to Mikov & Bond’s 2.04, and 68%).

This gives us three distance matrices:  distance in miles, distance in life history strategy and distance in genetic traits.  I then used a Mantel test to compare these.

Genetic and life history measures are correlated (r = 0.88, p < 0.0001), as in the paper above (in the regression, r = 0.78-0.84).  Both the genetic and life history measures were correlated with geographic distance (r = 0.36, p < 0.0001; r = 0.27, p = 0.0003), which suggests that they are not independent (i.e. a country is likely to be more similar to its neighbour than a distant culture).

However, there is still a significant correlation between genetic and life history measures when controlling for geographic distance (r = 0.87, p = 0.0001).  In fact, the correlation is barely affected at all when partialling out the geographic distance.

So, it appears that the correlation is somewhat robust to controlling for non-independence.  But will it play out in the long-term?

Source data and analysis script: MikovBond_Mantel

Edit: Michael Minkov has been in touch, and argues that psychological phenomena, such as happiness, values, attitudes etc. can’t be borrowed across cultures.  They depend on particular economic conditions, which also can’t be borrowed in the same way that a word or an artefact can be borrowed.

Edit2: Above, I used raw distance, but log distance is probably a better measure.  Both genetic index and life history index are more strongly correlated with log geographic distance (r = 0.42, p < 0.0001; r = 0.35, p < 0.0001).  However, there’s not much difference in the correlation between genetic and life history measures when controlling for log geographic distance (r = 0.86, p < 0.0001).

Evolve an App Name: Results

On Thursday I ran an experiment to evolve an app name.  And here’s the name that won:

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I’m not sure if I could cope with having to say ‘Lingo Bingo’ for the next two months, but we’ll see.

Here’s how it worked:

  • Show the participant 10 app names for 20 seconds
  • Hide the names and ask the participant to recall them
  • Pass on what they recall as the stimuli for the next participant to remember

(you can still take part in the experiment here)

We predicted that the most striking, memorable names would be remembered and passed on, while the less memorable ones would be selected out.  That is, the names would evolve to fit the brains of app-users by being repeatedly learned and produced (iterated learning):

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54 people took part in the experiment.

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Natural causes of language

Natural causes of language by Nick Enfield discusses theories behind cultural transmission of language.  From the blurb:

What causes a language to be the way it is? Some features are universal, some are inherited, others are borrowed, and yet others are internally innovated. But no matter where a bit of language is from, it will only exist if it has been diffused and kept in circulation through social interaction in the history of a community. This book makes the case that a proper understanding of the ontology of language systems has to be grounded in the causal mechanisms by which linguistic items are socially transmitted, in communicative contexts.

I like the argument that a particular ‘language’ (like English or Welsh) is not a real entity, but a “convenient fiction” – something I also argued in my thesis.

It’s a special book in two senses.  First, it comes from the new Language Sciences Press: an open access publisher where publishing costs nothing to the author and reading costs nothing to the reader.   Hopefully we’ll see this being used to good effect.

Secondly, it comes with a video introduction from the author!

Different approaches to causality in linguistics

Damian Blasi and I are organising a workshop on Causality in the language sciences (call for presentations now open!). As we were talking about the themes, we realised that there are multiple ways that a causal mechanism may manifest itself in the real world, and that very different statistical approaches may be applicable to each.

Below is the bare bones of a paper that should be coming out in an edited volume on Dependencies in language.  We discuss three types of causal mechanism, with examples from linguistics.

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How to speak stone-age bullshit

This is a guest post by Christine Cuskley.

As a general rule, there is much that is very badly written about specialist academic disciplines. From farts curing cancer to hot wet aliens, academic research often isn’t well-represented in popular outlets. Research on language and language evolution are no exception. So, generally, people who spend their working days immersed in language research let such flawed reports flow over them like so many offers to publish their thesis for the small fee of £300. You can’t possibly feel miffed at every one or you would explode and get nothing done, and there’s already so much on the internet to distract me even the most focused linguist.

But today I’ve seen something so utterly cringeworthy that it simply shall not pass. In a recent article for The Daily Mail, a man named Christopher Stevens For The Daily Mail adapts an excerpt from a book called Written in Stone, which is by Christopher Stevens (presumably) For Himself. I will direct all criticism towards his nom de plume, on the off chance that he originally submitted a clear, well-thought out, and accurate excerpt from his excellent book which was then mercilessly butchered by an ignorant editor. As an up-front disclaimer, I haven’t actually read the book itself, and I am very unlikely to. Assuming this adapted excerpt is any indication, the book is a mess.

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The next event in the ways to (proto)language conference series has been announced and is being held in Rome!
Call for Papers below:
24-26 SEPTEMBER 2015
Roma Tre University
Michael C. Corballis (University of Auckland)
Dan Dediu (Max Plank Institute for Psycholinguistics)
Francesco D’Errico (University of Bordeaux)
Daniel Dor (Tel Aviv University)
Ian Tattersall (American Museum of Natural History)
Elisabetta Visalberghi (Institute of Cognitive Sciences and Technologies – CNR Rome)
We call for:
The list of conference areas includes:
* animal cognition
* animal communication
* anthropology (linguistic, social, cultural)
* cognitive science
* cognitive semiotics
* computational modelling
* general evolutionary theory
* genetics of language
* gesture studies
* linguistics
* neuroscience of language
* paleoanthropology
* philosophy of biology
* philosophy of language
* Pleistocene archaeology
* primatology
* psychology (evolutionary, comparative, developmental)
* speech physiology
Talks and posters:
Please submit an abstract of 400 words prepared for anonymous review to the EasyChair website:
Submissions should be suitable for 30 minutes presentation (20 min for presentation and 10 min for discussion).
Please submit a proposal including: (a) Title of the symposium, (b) name and affiliation of the organizers, (c) a general description of the symposium (400 words), (d) abstract of each contributed talk (100-150 words)
Submissions should be suitable for a two-hour session and include 3 to 5 presentations.
The organizers are responsible for submitting the full symposium program to the EasyChair website: The organizers will also act as chairs of their session.
Note: abstracts of talks, posters and symposia must be submitted in .doc (or .docx) or .txt, no PDF format will be accepted.
Submission deadline: 1 February 2015
Notifications of acceptance: 20 March 2015
Early registration deadline: 30 June 2015
Conference: 24-26 September 2015
The Protolang conference series creates an interdisciplinary platform for scholarly discussion on the origins of symbolic communication distinctive of human beings. The thematic focus of Protolang is on delineating the genetic, anatomical, neuro-cognitive, socio-cultural, semiotic, symbolic and ecological requirements for evolving (proto)language. Sign use, tools, cooperative breeding, pointing, vocalisation, intersubjectivity, bodily mimesis, planning and navigation are among many examples of such possible factors through which hominins have gained a degree of specificity that is not found in other forms of animal communication and cognition. We aim at identifying the proximate and ultimate causes as well as the mechanisms by which these requirements evolved; evaluating the methodologies, research tools and simulation techniques; and enabling extended and vigorous exchange of ideas across disciplinary borders.We invite scholars from A(rcheology) to Z(oology), and all disciplines in between, to contribute data, experimental and theoretical research, and look forward to welcoming you at one of our conferences!