Sticking the tongue out: Early imitation in infants

April 6, 2013 in Research Blogging, Uncategorized

Famous picture of Albert Einstein sticking out his tongue.

Albert Einstein sticking out the tongue to a neonate in an attempt to test their imitation of tongue protrusion.

The nativism-empiricism debate haunts the fields of language acquisition and evolution on more than just one level. How much of children’s social and cognitive abilities have to be present at birth, what is acquired through experience, and therefore malleable? Classically, this debate resolves around the poverty of stimulus. How much does a child have to take for granted in her environment, how much can she learn from the input?

Research into imitation has its own version of the poverty of stimulus, the correspondence problem. The correspondence problem can be summed up as follows: when you are imitating someone, you need to know which parts of your body map onto the body of the person you’re trying to imitate. If they wiggle their finger, you can establish correspondence by noticing that your hand looks similar to theirs, and that you can do the same movement with it, too. But this is much trickier with parts of your body that are out of your sight. If you want to imitate someone sticking their tongue out, you first have to realise that you have a tongue, too, and how you can move it in such a way that it matches your partner’s movements.

Read the rest of this entry →

Iterated learning using YouTube videos

April 2, 2013 in Uncategorized

I recently discovered that videos uploaded to YouTube are automatically transcribed (if they’re in English).  As you might guess, the transcriptions are not perfect, so there will be a discrepancy between what the speaker actually said and what is transcribed.  This is essentially all you need to run an iterated learning experiment (e.g. Kirby, Cornish & Smith, 2008).  Iterated learning is a process of repeatedly transmitting a signal through a bottleneck.  For instance, language is transmitted from adults to children, who learn its rules.  These children then go on to transmit this language to their own children.

Screen Shot 2013-03-30 at 11.49.20

Simon Kirby and colleagues have discovered that this process leads to languages becoming both more learnable and more expressive over time.  This happens by the emergence of compositionality: parts of a word become systematically linked to parts of its meaning.  See some posts by Hannah and Wintz on these experiments.

But can we see the same process with non-human learners?  Here’s how iterated learning with YouTube works:

  1. Record yourself saying something.
  2. Upload the video to YouTube
  3. Let it be automatically transcribed (usually takes about 10 minutes for a short video)
  4. Record yourself saying the text from the automatic transcription
  5. Go to 2

Here’s a diagram of the procedure:

Slide1

Read the rest of this entry →

More Language Evolution positions available

March 15, 2013 in Uncategorized

It’s job frenzy out there. You can see here seven postdoctoral positions in the Dutch research consortium ”Language in Interaction” including one on language evolution below:

WP 5: Language evolution and diversity

The goal of this WP is to contribute to a better understanding of the biological underpinnings of linguistic universality as well as diversity, both at the population level (between languages and between species) and at the individual level (within a language). We are looking for a postdoctoral researcher in this area. The preferred area of specialization is evolutionary modelling of language with respect to diversity in communication. Other possible areas of expertise may include language diversity, individual differences in language abilities, animal communication, and genetic influences on speech and language.

Contact information WP 5: Prof. Pieter Muysken, p.muysken@let.ru.nl

The deadline for applications is May 15, 2013 for a September start date. More details on the document here:

https://docs.google.com/file/d/1HErCprWm1KZauFiKNEaswRmblG2HJZlydRSbDODEKfVkZ48BQzen3ems-h43/edit

Positions available on major Research Project on Cultural and Cognitive Evolution

March 8, 2013 in Uncategorized

The university of St. Andrews is on a hiring frenzy:

Applications are invited to join an interdisciplinary research programme directed by Professors Kevin Laland (School of Biology) and Andrew Whiten (School of Psychology and Neuroscience) at the University of St Andrews’ Centre for Social Learning and Cognitive Evolution. “Exploring the Evolutionary Origins of Culture Complexity, Creativity and Trust” is funded through a major grant from the John Templeton Foundation. Successful candidates will join a team of over 20 researchers working on the project, studying aspects of social learning, innovation and cultural evolution in monkeys, apes and human participants, employing a diversity of techniques including systematic observation, experiments and statistical modelling.

Two Lectureships: Lecturer in Behavioural and Evolutionary Biology (School of Biology);

Lecturer in Comparative, Evolutionary or Developmental Psychology (School of Psychology). Salary £37,382 – £45,941 per annum. Ref No: ML1133. Closing Date 7 April 2013.

Eight Postdoctoral Research Assistantships: £30,424 – £36,298 per annum. Ref No: SB1299.Closing Date 5 April 2013.

Up to ten PhD Scholarships. For further particulars and how to apply see http://lalandlab.st-andrews.ac.uk/opportunities.html.

Positions are for 33 months (salaried posts) or three years (PhD), commencing 1st September 2013 or as soon as possible thereafter. For the Lectureships & Postdoctoral Research Assistants only, we encourage applicants to apply online at www.vacancies.st-andrews.ac.uk/welcome.aspx, where further particulars of all posts can be viewed. However if you are unable to do this, please call +44 (0)1334462571 for an application pack.

Please quote the appropriate reference number on all correspondence.

The University is committed to equality of opportunity.

The University of St Andrews is a charity registered in Scotland (No SC013532).

The press release announcing the grant states:

The new project will use comparative studies of social learning among monkeys, apes and human children together with sophisticated statistical modeling and a diverse range of other methods to address a suite of such ‘Big Questions’ about the evolution of culture, a field in which St Andrews is a world leader. “When we talk of ‘culture’ in this project, we include everything that is learned from others, from our language to our technology and moral codes. Our cultural nature is arguably the most important characteristic that separates us from even our closest primate relatives”, says Professor Whiten. “Nevertheless, we can learn much about the evolutionary roots of our cultural capacities by studying the social traditions of monkeys and apes, and that will be an important part of this project”.

“Our unique human ability to make cultures evolve cumulatively, building on what others achieved before us, depends on two essential elements highlighted in the project title”, adds Professor Laland: “creativity, which produces new innovations, and trust, which guides which innovations are adopted and spread. We will be investigating how humans and other animals decide whom to trust as sources of cultural information and what other forms of cultural filtering are important”.

So it sounds very relevant for Language Evolution bods!

Festival of Bad Ad Hoc Hypotheses

March 7, 2013 in Uncategorized

Zach Weinersmith of SMBC comics and various science folk are putting on a Festival of Bad Ad Hoc Hypotheses.  The festival will include presentations of “well-argued and thoroughly researched but completely incorrect evolutionary theory”.  They’re looking for people to give 5 minute presentations.  It takes place at MIT on the 20th April, submissions are due 10th March.

Finally, a place for all our hard work on spurious correlations in culturally evolved systems.

More details here

The Evolution of Speech: Lip-smacking monkeys

March 6, 2013 in Abstracts, Evolution

In January, Ghazanfar, Morrill & Kayser published a paper in PNAS entitled “Monkeys are perceptually tuned to facial expressions that exhibit a theta-like speech rhythm”. The abstract is below:

Human speech universally exhibits a 3- to 8-Hz rhythm, corresponding to the rate of syllable production, which is reflected in both the sound envelope and the visual mouth movements. Artificial perturbation of the speech rhythm outside the natural range reduces speech intelligibility, demonstrating a perceptual tuning to this frequency band. One theory posits that the mouth movements at the core of this speech rhythm evolved through modification of ancestral primate facial expressions. Recent evidence shows that one such communicative gesture in macaque monkeys, lip-smacking, has motor parallels with speech in its rhythmicity, its developmental trajectory, and the coordination of vocal tract structures. Whether monkeys also exhibit a perceptual tuning to the natural rhythms of lip-smacking is unknown. To investigate this, we tested rhesus monkeys in a preferential-looking procedure, measuring the time spent looking at each of two side-by-side computer-generated monkey avatars lip-smacking at natural versus sped-up or slowed-down rhythms. Monkeys showed an overall preference for the natural rhythm compared with the perturbed rhythms. This lends behavioral support for the hypothesis that perceptual processes in monkeys are similarly tuned to the natural frequencies of communication signals as they are in humans. Our data provide perceptual evidence for the theory that speech may have evolved from ancestral primate rhythmic facial expressions.

Writing in Nature, last week, Techumseh Fitch wrote a short news article on Ghazanfar’s findings including a very concise but clear outline on the two main hypotheses for the evolutionary origin of human speech, which he also goes over in his 2010 book. Namely, the hypothesis that speech is derived from primate vocalizations as the same vocal production system (lungs, larynx and vocal tract) is used to produce both primate calls and speech. However, as Fitch states, “a problem is that human speech is unique among primate vocalizations in being a very flexible, learned signal, whereas most primate calls have a strong, species-specific genetic determination. The ‘vocal origins’ hypothesis favours evolutionary continuity of vocal production over a hypothetical discontinuity in vocal control and vocal learning.”

The second hypothesis is MacNeilage’s hypothesis that speech rhythms originated not in the vocal, but in the visual domain. As the mouth generates not just vocal, but also visual, signals. The strength in this hypothesis lies in the fact that these articulators are under learned voluntary control in non-human primates. MacNeilage argues that speech develops in babies’ babbling as a lip-smacking behaviour superimposed on a vocal signal. Fitch states: “This rhythmic stream is then differentially modified, by learned tongue and lip movements, into the vowels and consonants of speech. Support for this hypothesis comes from previous work demonstrating that the detailed kinematics of lip-smacking are strikingly similar to those of speech. But Ghazanfar and colleagues’ work adds support from the domain of perception, indicating that perceptual tuning for the two signal classes is also consistent with MacNeilage’s hypothesis.”

As has been covered on this blog before, a lot of research on speech evolution has focused on the descended larynx. This new research adds to the body of work that suggest that anatomy might not be as important as first imagined, and that neural control and vocal learning may be much more important.

Culture – Language – Cognition: Special Issue of Pragmatics & Cognition on Dan Everett’s ‘Language: The Cultural Tool’

March 4, 2013 in Abstracts, Science

Everett

The 20th anniversary special commemorative issue of Pragmatics & Cognition features a number of interesting articles which comment on linguist Dan Everett‘s 2012 book “Language: The Cultural Tool“. In this book,  Everett, who is best known for his work on the indigenous language Pirahã,  argues for the important of culture and interaction and against the Chomskyan idea of innately specified, specifically linguistic knowledge or architecture. The issue also includes replies by Dan Everett to each of his commentators.

Unfortunately, the articles are all behind a paywall, but the abstracts already make some interesting points.

Raymond W. Gibbs, Jr. and Nathaniel Clark argue that language should not be conceived of as emerging from an ‘interactional instinct’, as Everett does. Instead,

“language use, and coordinated communication more generally, is an emergent product of human self-organization processes. Both broad regularities and specific variations in linguistic structure and behavior can be accounted for by self-organizational processes that operate without explicit internal rules, blueprints, or mental representations. A major implication of this view is that both linguistic patterns and behaviors, within and across speakers, emerge from the dynamical interactions of brain, body, and world, which gives rise to highly context-sensitive and varied linguistic performances.”

 

Read the rest of this entry →

A review of a review on Fitch’s The Evolution of Language

March 1, 2013 in Reviews

fitch language evolutionMaggie Tallerman has published a review of Techumseh Fitch’s 2010 book, “The Evolution of Language” in the journal of linguistics. It is largely very critical, mostly of Fitch’s ideas about a musical protolanguage stage preceding language, and of the fact that the focus of the book is largely about vocal imitation and the evolution of speech, rather than on linguistic (i.e. cognitive) features such as syntax, semantics and phonology. Tallerman is also very critical of a lack of an emphasis on the uniqueness of human language, stating:

The first problem is that there isn’t enough emphasis on the exceptional nature of language as a human faculty. In particular, the putative parallels with animal communication and cognition are at times exaggerated. Take statements like this: ‘[e]ven syntax, at least at a simple level, finds analogs in other species (e.g. bird and whale ‘‘song’’) which can help us to understand both the brain basis for syntactic rules and the evolutionary pressures that can drive them to become more complex’ (18). While there’s SOME truth in the first half, given the existence of both hierarchical structure and simple dependencies in animal ‘syntax’ (see Hurford 2012 for an excellent survey), I fear that a non-linguist reading the claim that analogues of syntax are found in other animals would get entirely the wrong idea. Grammatical systems in language are NOT merely a more complex version of animal communication systems, which are entirely non-compositional, with no duality of patterning, and which do not contain word classes or headed phrases.

I feel like Tallerman is claiming that her view that language is exceptional as indisputable fact, rather than as a standpoint. However, the view that language is unique among cognitive processes and is unique to humans, is still a very contentious matter and many linguists, biologists and cognitive scientists hold the legitimate opinion that language may well just be the result of domain general cognitive processes and that comparative studies of human and animal abilities have a large roll to play in the future of language evolution research. This is certainly a very attractive standpoint for biologists. I know Hauser, Chomsky & Fitch (2002), the paper for which Fitch is probably most famous in language evolution, put some emphasis on their being an faculty for language, in both a broad (FLB) and narrow (FLN) sense, and Tallerman mentions that the FLN is, “namely, whatever is both uniquely human and uniquely linguistic”. But, Hauser, Chomsky & Fitch (2002) in fact argue that “FLN may have evolved for reasons other than language, hence comparative studies might look for evidence of such computations outside of the domain of communication (for example, number, navigation, and social relations)” – which is completely consistent with the emphasis being away from language being so exceptional, and on the importance of animal studies.

Of course, any good text book should cover both sides of the argument, and perhaps Fitch doesn’t spend enough time covering the ins and outs of a controversy so central to the field of language evolution, but I don’t think that Tallerman’s criticisms consider the importance of both sides of the argument either. I’m also not sure why she quotes Chomsky at the beginning of the paper. Chomsky said in his famous UCL talk:

There’s a field called ‘evolution of language’ which has a burgeoning literature, most of which in my view is total nonsense … In fact, it isn’t even about evolution of language, it’s almost entirely speculations about evolution of communication, which is a different topic

Fitch has written a couple of papers with Chomsky, but the quote’s presence is confusing in a review of a book where Chomsky is not an author, and I can see no other reason to include it other than to confound Fitch with Chomsky’s views, which isn’t a very fair way to start a review judging Fitch’s book.

Beyond this, the main bulk of the paper is on Fitch’s treatment of the problem of cheap, honest signals and also of protolanguage and, in particular,  musical protolanguage. She raises some excellent points and in light of the fact that I have things to be doing, you should go and read it here if you’re interested: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8836742

Whorfian economics reconsidered: Residuals and Causal Graphs

February 28, 2013 in Uncategorized

Yesterday I posted an analysis of some work by Prof. Keith Chen on the link between future tense marking and economic decisions.  Prof. Chen made some suggestions about changes to the analysis, some of which I’ve carried out here.  The new results below indicate that the link between future tense and the propensity to save is more robust than the previous post suggested, which is quite embarrassing, but I submit the findings here anyway.

One of Prof. Chen’s points was that I was using simple linear regression, while his analysis used conditional logit modelling.  This is much more computationally intense, and it’s not feasible for me to run 145 logit models for the given size of dataset (R was telling me it needed 13GB of memory to run an analysis of one linguistic variable! Help, anyone?).

Another suggestion was to look at which linguistic variables explain the residual variation in a model with non-linguistic variables.  That is, controlling for non-linguistic variables such as age, sex and number of children, how much extra variance does a particular linguistic variable account for?

I analysed this by comparing two models for each linguistic variable (using ANOVAS, although the results are equivalent with regressions).  Each model had the propensity to save as the dependent variable and independent variables including age, sex, employment status, marriage status, level of education, religion, number of children and survey year.  The second model also included the linguistic variable.  I then compared the improvement in the model fit using the F-score of the difference in residuals.  (There are some problems here, because different linguistic features will be represented in different sub-sets of the data, but we’ll ignore this for now.)

Read the rest of this entry →

Whorfian economics reconsidered: Why future tense?

February 26, 2013 in Uncategorized

Update: I have carried out some more analyses that paint a different picture to the one presented below.  Oops!

A recently accepted paper by Keith Chen has been getting a lot of press coverage. Chen has discovered a close link between the properties of the language people speak and their economic decisions. People who speak languages which mark the future tense differently to the present tense tend to make fewer provisions for the future. This includes economic decisions  such as being less likely to save money, but also secondary indicators such as greater prevalence of smoking and obesity.

The hypothesis is that marking the future tense differently makes the future seem further away, and therefore you are less likely to plan for the future.

Chen has talked about this hypothesis at a TED conference and has been covered in the media, most recently in a BBC economics column (which, to be fair, was fairly critical). The hypothesis has been criticised by several linguists, notably on language log (and a great model post by Mark Liberman), where Chen gave a response. The data has been criticised (e.g. English is marked as ‘strong future tense marking’, but has a range of ways of using present tense for future time reference), as well as the thinking behind the hypothesis itself (e.g. why wouldn’t marking a difference in the language actually make the future MORE salient?). Some have also pointed out weaknesses in the statistical claim, for instance, Östen Dahl has pointed out that speaking a language with front rounded vowels is also a good predictor of economic decisions.

Here at Replicated Typo, we have discussed many cases of spurious correlations – statistical links between cultural traits that are unlikely to be causal.  James Winters and I recently published a paper on the dangers of making claims based on large-scale, cross-cultural statistics. Basically, it’s very easy to find statistical links between any two variables because cultrual traits are inherited in bundles (they are not independent).

In this post, I address an issue that I haven’t seen systematically answered yet: Chen predicts that there is a correlation between future tense marking and economic decisions, and finds a strong link. However, he should also predict that future tense marking is a stronger predictor than other linguistic variables.  In other words, can we find a different aspect of language that is even better at predicting economic behaviour?  Here I test the link between the propensity to save money and many different linguistic factors.

Read the rest of this entry →