Does Language Shape Thought? Different Manifestations of the Idea of Linguistic Relativity (I)

Does the language we speak influence or even shape the way we think? Last December, there was an interesting debate over at The Economist website with Lera Boroditsky defending the motion, and Language Log’s Mark Liberman against the motion (who IMO, both did a very good job).
The result of the online poll was quite clear: 78% agreed with the motion, while 22% disagreed.

There are, however, three main problems with this way of framing the question: First, it’s not really clear what ‘language’ really is, second, the same goes for “thought”, and third, there are many many ways of how “influencing” and “shaping” something can be conceptualized.
In this post I want to focus on the third problem and present a very useful classification system for hypotheses about linguistic relativity outlined in an article by Phillip Wolff and Kevin J. Holmes, which was published in the current issue Wiley Interdisciplinary Review: Cognitive Science.

Continue reading “Does Language Shape Thought? Different Manifestations of the Idea of Linguistic Relativity (I)”

Bayesian phylogenetic analysis of Japonic languages

Lee & Hasegawa (2011) use phylogenetic methods to trace the origins of Japonic languages and dialects.  Two hypotheses are considered:  First, the farming/language dispersal hypothesis posits that the main factor for the divergence of genetic and linguistic diversity was agricultural expansion.  Second, the diffusion/transformation hypothesis posits that cultural innovations such as farming can diffuse between societies, and so genetic and linguistic diversity should not be linked.  The estimate of the common linguistic ancestor was in accordance with the farming/language dispersal hypothesis, again suggesting that that linguistic diversity followed genetic diversity.

The study is notable in considering dialects as well as languages and using etymology dictionaries to reconstruct forms from Middle and Old Japanese.  The analysis is also done with their own reconstructions and another, unrelated set.  The technique is similar to that used by Russel Gray et al. (2009) to study Pacific settlement patterns.

Lee S, & Hasegawa T (2011). Bayesian phylogenetic analysis supports an agricultural origin of Japonic languages. Proceedings. Biological sciences / The Royal Society PMID: 21543358

Gray, R., Drummond, A., & Greenhill, S. (2009). Language Phylogenies Reveal Expansion Pulses and Pauses in Pacific Settlement Science, 323 (5913), 479-483 DOI: 10.1126/science.1166858

Bonobos Extract Meaning from Call Sequences

A new study appeared yesterday on PlosOne by Clay and Zuberbühler of St Andrews University on the communicative ability of bonobos.

Studies have been done in the past on language-trained bonobos such as Kanzi which have revealed some remarkable abilities that the species has with regards to representational and communication tasks.

These studies have focussed on trained apes which are reared in unnatural environments and extensively trained on artificial languages. This has produced some interesting results though research into bonobos’ natural communication has been thin on the ground until now.

Clay and Zuberbühler address this gap in the research with a playback study on the natural vocal communication of bonobos.

Bonobos are known to produce five distinct vocal signals when finding food, these have been demonstrated to be combined together to make longer call sequences. The study found that individual call types were poor indicators of food quality but that calls which displayed a concatenation of signals were much better indicators.

The study looked into whether receivers could extract meaning about the quality of food encountered by the caller by integrating across different call sequences.

They started by training four captive bonobos to find two types of foods in two different locations, those which are more preferred such as kiwis and those which are less preferred such as apples. The apes were recorded when finding these different food types and these recordings were used in the playback experiments. When the bonobos discovered their preferred food they emitted higher pitched long barks and short “peeps” and when they discovered the less-preferred food they made lower pitch “peep-yelps” and yelps. Sequences of the four calls which used different compositions were played back to bonobos who were familiar with those apes who had originally made the calls. All sequences contained the same number of calls. In response to these playbacks the study found that the apes devoted significantly more effort and time searching the space which was known to contain the food type indicated by the call sequence (shown in the graph below).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The bonobos were shown to attend not just to individual calls but to the entire sequences before they made inferences about the food encountered by a caller.

These results provide the first empirical evidence that bonobos are able to extract information about external events by attending to natural vocal sequences made by other bonobos. This study really highlights the importance of call combinations in their natural communication system.

References
Clay Z, Zuberbühler K, 2011 Bonobos Extract Meaning from Call Sequences. PLoS ONE 6(4): e18786. doi:10.1371/journal.pone.0018786

New Book. New Ideas?

A new book is to be published on May the 24th. By John F. Hoffecker the book is entitled “Landscape of the Mind: Human Evolution and the Archaeology of Thought” – it aims to look at the emergence of human thought and language through archaeological evidence

Archeologists often struggle to find fossil evidence pertaining to the evolution of the brain. Thoughts are a hard thing to fossilize. However, John Hoffecker claims that this is not the case and fossils and archaeological evidence for the evolution of the human mind are abundant.

Hoffecker has developed a concept which he calls the “super-brain” which he hypothesises emerged in Africa some 75,000 years ago. He claims that human’s ability to share thoughts between individuals is analogous to the abilities of honey bees who are able to communicate the location of food both in terms of distance and direction. They do this using a waggle-dance. Humans are able to share thoughts between brains using communicative methods, the most obvious of these being language.

Fossil evidence for the emergence of speech is thin on the ground and, where it does exist, is quite controversial. However, symbols emerging in the archaeological record coincides with an increase in evidence of creativity being displayed in many artifacts from the same time. Creative, artistic designs scratched on mineral pigment show up in Africa about 75,000 years ago and are thought to be evidence for symbolism and language

Hoffecker also hypothesises that his concept of the super-brain is likely to be connected to things like bipedalism and tool making. He claims that it was tool making which helped early humans first develop the ability to represent complex thoughts to others.

He claims that tools were a consequence of bipedalism as this freed up the hands to make and use tools. Hoffecker pin points his “super-brain” as beginning to emerge 1.6 million years ago when the first hand axes began to appear in the fossil record. This is because hand axes are thought to be an external realisation of human thought as they bear little resemblance to the natural objects they were made from.

By 75,00 years ago humans were producing perforated shell ornaments, polished bone awls and simple geometric designs incised into lumps of red ochre.

Humans are known to have emerged from Africa between 60,00 to 50,000 years ago based on archeological evidence. Hoeffecker hypothesises that – “Since all languages have basically the same structure, it is inconceivable to me that they could have evolved independently at different times and places.”

Hoeffecker also lead a study in 2007 that discovered a carved piece of mammoth ivory that appears to be the head of a small figurine dating to more than 40,000 years ago. This is claimed to be the oldest piece of figurative art ever discovered. Finds like this illustrate the creative mind of humans as they spread out of Africa.

Figurative art and musical instruments which date back to before 30,000 years ago have also been discovered in caves in France and Germany.

This looks to be nothing new but archaeological evidence is something which a lot of people interested in language evolution do not often discuss. I also don’t really know what to think of Hoeffecker’s claim that “all languages basically have the same structure”. What do you think?

Return of the Language Evolution Tree

A while ago, some collegues and I noticed that two prominent books on Language Evolution -Christiansen & Kirby’s Language Evolution and Fitch’s Evolution of Language – both included a picture of an acacia tree in the sunset on their covers.  On closer analysis, it turned out that they were the same tree:

Thus began the Acacia Tree Hypothesis of Language Evolution.

Following this up, I was thinking about Dediu & Ladd’s discovery that linguistic tone is has certain genetic correlates. Here’s the map of languages with linguistic tone:

However, I suspected the devious influence of acacia trees and so I found some information on their geographic distribution:

As I suspected, countries in which the acacia tree Acacia nilotica grows are significantly more likely to have tonal languages:

Tone No Tone
Acacia Trees 163 117
No Acacia Trees 104 237

(Chi-squared with Yates’ continuity correction = 47.1, df = 1, p < 0.0001, data from Crop Protection Consortium and the World Atlas of Language Structures).

The plot thickens …

 

Dediu, D., & Ladd, D. R. (2007). Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, Microcephalin and ASPM. Proceedings of the National Academy of Sciences, 104, 10944–10949.

Fitch, W. T. 2010 The evolution of language. Cambridge, UK: Cambridge University Press.

Christiansen, M. and Kirby, S. (2003). Language Evolution. Oxford University Press.

 

Update:

I’ve added the images David mentioned to the post:

Also, The Babel’s Dawn blog banner

The Return of the Phoneme Inventories

Right, I already referred to Atkinson’s paper in a previous post, and much of the work he’s presented is essentially part of a potential PhD project I’m hoping to do. Much of this stems back to last summer, where I mentioned how the phoneme inventory size correlates with certain demographic features, such as population size and population density. Using the the UPSID data I generated a generalised additive model to demonstrate how area and population size interact in determining the phoneme inventory size:

Interestingly, Atkinson seems to derive much of his thinking, at least in his choice of demographic variables, from work into the transmission of cultural artefacts (see here and here). For me, there are clear uses for these demographic models in testing hypotheses for linguistic transmission and change, as I see language as a cultural product. It appears Atkinson reached the same conclusion. Where we depart, however, is in our overall explanations of the data. My major problem with the claim is theoretical: he hasn’t ruled out other historical-evolutionary explanations for these patterns.

Before we get into the bulk of my criticism, I’ll provide a very brief overview of the paper.

Continue reading “The Return of the Phoneme Inventories”

Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa

Just read about an article on phoneme diversity via GNXP and Babel’s Dawn. Hopefully I’ll share some of my thoughts on the paper this weekend as it clearly ties in with work I’m currently doing (see here and here). Below is the abstract:

Human genetic and phenotypic diversity declines with distance from Africa, as predicted by a serial founder effect in which successive population bottlenecks during range expansion progressively reduce diversity, underpinning support for an African origin of modern humans. Recent work suggests that a similar founder effect may operate on human culture and language. here I show that the number of phonemes used in a global sample of 504 languages is also clinal and fits a serial founder-effect model of expansion from an inferred origin in Africa. This result, which is no explained by more recent demographic history, local language diversity, or statistical non-independence within language families, points to parallel mechanisms shaping genetic and linguistic diversity and supports an African origin of modern human languages.

Reference: Atkinson, Q.D (2011). Phonemic Diversity Supports a Serial Founder Effect Model of Language Expansion from Africa. Science 332, 346. DOI: 10.1126/science.1199295.

Update: I’ve given a lengthier response here.

The Parental Antagonism Theory of Language Evolution

Human Biology are publishing a special issue on “Integrating genetic and Cultural Evolutionary Approaches to Language” this month! Abstracts for all of the papers can be found here.

William Brown‘s paper has been published on his blog ahead of the boat today. The Abstract is below and there is a link to the paper at the bottom.

Language—as with most communication systems—likely evolved by means of natural selection. Accounts for the natural selection of language can usually be divided into two scenarios, either of which used in isolation of the other are insufficient to explain the phenomena: (1) there are group benefits from communicating, and (2) there are individual benefits from being a better communicator. In contrast, this paper argues that language emerged during a coevolutionary struggle between parental genomes via genomic imprinting, which is differential gene expression depending on parental origin of the genetic element. It is hypothesized that relatedness asymmetries differentially selected for patrigene-caused language phenotypes (e.g., signals of need) to extract resources from mother early in child development and matrigene-caused language phenotypes (e.g.,  socially transmitted norms) to influence degree of cooperativeness  among kin later in development. Unlike previous theories for language evolution, parental antagonism theory generates testable predictions at the proximate (e.g., neurocognitive areas important for social transmission and language capacities), ontogenetic (e.g., the function of language at different points of development), ultimate (e.g., inclusive fitness), and phylogenetic levels (e.g., the spread of maternally derived brain components in mammals, particularly in the hominin lineage), thus making human capacities for culture more tractable than previously thought.

Brown, W.M. (2011). The parental antagonism theory of language evolution: Preliminary evidence for the proposal. Human Biology, 83 (2)

Evolved structure of language shows lineage-specific trends in word-order universals

Via Simon Greenhill:

Dunn M, Greenhill SJ, Levinson SC, & Gray RD (2011). Evolved structure of language shows lineage-specific trends in word-order universals. Nature.

Some colleagues and I have a new paper out in Nature showing that the evolved structure of language shows lineage-specific trends in word-order universals. I’ve written an overview/FAQ on this paper here, and there’s a nice review of it here and here.

The Abstract:

Languages vary widely but not without limit. The central goal of linguistics is to describe the diversity of human languages and explain the constraints on that diversity. Generative linguists following Chomsky have claimed that linguistic diversity must be constrained by innate parameters that are set as a child learns a language. In contrast, other linguists following Greenberg have claimed that there are statistical tendencies for co-occurrence of traits reflecting universal systems biases, rather than absolute constraints or parametric variation. Here we use computational phylogenetic methods to address the nature of constraints on linguistic diversity in an evolutionary framework. First, contrary to the generative account of parameter setting, we show that the evolution of only a few word-order features of languages are strongly correlated. Second, contrary to the Greenbergian generalizations, we show that most observed functional dependencies between traits are lineage-specific rather than universal tendencies. These findings support the view that—at least with respect to word order—cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states.

 

Colour terms and national flags

I’m currently writing an article on the relationship between language and social features of the speakers who use it. As studies such as Lupyan & Dale (2010) have discovered, language structure is partially determined by social structure.  However, it’s also probable that many social features of a community are determined by its language.

Today, I wondered whether the number of basic colour terms a language has is reflected in the number of colours on its country’s flag. The idea being that a country’s flag contains colours that are important to its society, and therefore a country with more social tools for discussing colour (colour words) will be more likely to put more colours on its flag. It was a long shot, but here’s what I found:

The World Atlas of Language Structures has data on the number of basic colours in many languages (Kay & Maffi, 2008). Wikipedia has a list of country flags by the number of colours in them.  Languages with large populations (like English, Spanish etc.) were excluded.  It’s known that the number of basic colour terms correlates with latitude, so a partial correlation was carried out.  There was a small but significant relationship between the number of colour terms in a langauge and the number of colours on the flag where that language is spoken (r = 0.15, τ = 254, p=0.01, partial correlation, 2-tailed using Kendall’s tau).

Here’s the flag of Belize, where Garífuna is spoken (9-10 colours in the language, 12 colours on the flag):

Here is the flag of Nigeria where Ejagham is spoken (3-4 colours in the langauge, 2 colours on the flag):

Interestingly, the languages with the highest number of colours in their language and flag come from Central America while the majority of the languages with the lowest number of colours in their language and flag come from Africa.  Maybe there’s some cultural influence on neighbouring flags.

Update:

Here’s a boxplot, which makes more sense:

Also, I re-ran the analysis taking into account distance from the equator, speaker population and some properties of the nearest neighbour of each language (number of colours on flag and number of basic colours in langauge).  A multiple regression showed that the number of basic colours in a language is still a significant predictor of the number of colours in its national flag (r = 0.12, F(106,16)=1.8577, p= 0.03).  This analysis was done by removing languages with populations more than 2 standard deviations from the mean (9 languages out of 140).  The relationship is still significant with the whole dataset.

There are still problems with this analysis, of course.  For example, many of the languages in the data are minority languages which may have little impact on the national identity of a country.  Furthermore, the statistics may be compromised by multiple comparisons, since there may be a single flag for more than one language.  Also, a proper measure of the influence of surrounding languages would be better.  The nearest neighbour was supposed to be an approximation, but could be improved.

Lupyan G, & Dale R (2010). Language structure is partly determined by social structure. PloS one, 5 (1) PMID: 20098492

Kay, Paul & Maffi, Luisa. (2008). Number of Basic Colour Categories.In: Haspelmath, Martin & Dryer, Matthew S. & Gil, David & Comrie, Bernard (eds.) The World Atlas of Language Structures Online. Munich: Max Planck Digital Library, chapter 133.