Regularities in Cultural Evolution

I recently came across a post over at GNXP on the rise and crash of civilizations. It’s a really interesting discussion on a new paper by Currie et al. (2010), Rise and fall of political complexity in island South-East Asia and the Pacific. Here is the abstract:

There is disagreement about whether human political evolution has proceeded through a sequence of incremental increases in complexity, or whether larger, non-sequential increases have occurred. The extent to which societies have  decreased  in  complexity is  also unclear. These  debates have  continued  largely  in the absence  of rigorous, quantitative tests. We evaluated six competing models of political evolution in Austronesian-speaking societies using phylogenetic methods. Here we show that in the best-fitting model political complexity rises and falls in a sequence of small steps. This is closely followed by another model in which increases are sequential but decreases can be either sequential or in bigger drops. The results indicate that large, non-sequential jumps in political complexity have not occurred during the evolutionary history of these societies. This suggests that, despite the numerous contingent pathways of human history, there are regularities in cultural evolution that can be detected using computational phylogenetic methods. [My emphasis].

I don’t have much to add on the subject as I think Razib covered most of the relevant points, plus I haven’t even finished reading the paper yet (I’m hoping to get back into research blogging later this week). I will, however, post one of their figures that shows the dynamic between the rise and fall of political complexity, and how it shows regularity (btw, RJMCMC means Bayesian reversible-jump Markov chain Monte Carlo… if that helps you in any way):

Musings of a Palaeolinguist

Hannah recently directed me towards a new language evolution blog: Musings of a Palaeolinguist. From my reading of the blog, the general flavour seems to be focused on gradualist and abruptist accounts of language evolution. Here is a section from one of her posts, Evolution of Language and the evolution of syntax: Same debate, same solution?, which also touches on the protolanguage concept:

In my thesis, I went through a literature review of gradual and abruptist arguments for language evolution, and posited an intermediate stage of syntactic complexity where a language might have only one level of embedding in its grammar.  It’s a shaky and underdeveloped example of an intermediate stage of language, and requires a lot of exploration; but my reason for positing it in the first place is that I think we need to think of the evolution of syntax the way many researchers are seeing the evolution of language as a whole, not as a monolithic thing that evolved in one fell swoop as a consequence of a genetic mutation, but as a series of steps in increasing complexity.

Derek Bickerton, one of my favourite authors of evolutionary linguistics material, has written a number of excellent books and papers on the subject.  But he also argues that language likely experienced a jump from a syntax-less protolanguage to a fully modern version of complex syntax seen in languages today.  To me that seems unintuitive.  Children learn syntax in steps, and non-human species seem to only be able to grasp simple syntax.  Does this not suggest that it’s possible to have a stable stage of intermediate syntax?

I’ve generally avoided writing about these early stages of language, largely because I had little useful to say on the topic, but I’ve now got some semi-developed thoughts that I’ll share in another post. In regards to the above quote, I do agree with the author’s assertion of there being an intermediate stage, rather than Bickerton’s proposed jump. In fact, we see languages today (polysynthetic) where there are limitations on the level of embedding, with one example being Bininj Gun-wok. We can also stretch the discussion to look at recursion in languages, as Evans and Levinson (2009) demonstrate:

In discussions of the infinitude of language, it is normally assumed that once the possibility of embedding to one level has been demonstrated, iterated recursion can then go on to generate an infinite number of levels, subject only to memory limitations. And it was arguments from the need to generate an indefinite number of embeddings that were crucial in demonstrating the inadequacy of finite state grammars. But, as Kayardild shows, the step from one-level recursion to unbounded recursion cannot be assumed, and once recursion is quarantined to one level of nesting it is always possible to use a more limited type of grammar, such as finite state grammar, to generate it.

Some Links #19: The Reality of a Universal Language Faculty?

I noticed it’s almost been a month since I last posted some links. What this means is that many of the links I planned on posting are terribly out of date and these last few days I haven’t really had the time to keep abreast of the latest developments in the blogosphere (new course + presentation at Edinburgh + current cold = a lethargic Wintz). I’m hoping next week will be a bit nicer to me.

The reality of a universal language faculty? Melodye offers up a thorough post on the whole Universal Grammar hypothesis, mostly drawing from the BBS issue dedicated Evans & Levinson (2009)’s paper on the myth of language universals, and why it is a weak position to take. Key paragraph:

When we get to language, then, it need not be surprising that many human languages have evolved similar means of efficiently communicating information. From an evolutionary perspective, this would simply suggest that various languages have, over time, ‘converged’ on many of the same solutions.  This is made even more plausible by the fact that every competent human speaker, regardless of language spoken, shares roughly the same physical and cognitive machinery, which dictates a shared set of drives, instincts, and sensory faculties, and a certain range of temperaments, response-patterns, learning facilities and so on.  In large part, we also share fairly similar environments — indeed, the languages that linguists have found hardest to document are typically those of societies at the farthest remove from our own (take the Piraha as a case in point).

My own position on the matter is fairly straightforward enough: I don’t think the UG perspective is useful. One attempt by Pinker and Bloom (1990) argued that this language module, in all its apparent complexity, could not have arisen by any other means than via natural selection – as did the eye and many other complex biological systems. Whilst I agree with the sentiment that natural selection, and more broadly, evolution, is a vital tool in discerning the origins of language, I think Pinker & Bloom initially overlooked the significance of cultural evolutionary and developmental processes. If anything, I think the debate surrounding UG has held back the field in some instances, even if some of the more intellectually vibrant research emerged as a product of arguing against its existence. This is not to say I don’t think our capacity for language has been honed via natural selection. It was probably a very powerful pressure in shaping the evolutionary trajectory of our cognitive capacities. What you won’t find, however, is a strongly constrained language acquisition device dedicated to the processing of arbitrary, domain-specific linguistic properties, such as X-bar theory and case marking.

Babel’s Dawn Turns Four. In the two and half years I’ve been reading Babel’s Dawn it has served as a port for informative articles, some fascinating ideas and, lest we forget, some great writing on the evolution of language. Edmund Blair Bolles highlights the blog’s fourth anniversary by referring to another, very important, birthday:

This blog’s fourth anniversary has rolled around. More notably, the 20th anniversary of Steven Pinker and Paul Bloom‘s famous paper, “Natural Language and Natural Selection,” seems to be upon us. Like it or quarrel with it, Pinker-Bloom broke the dam that had barricaded serious inquiry since 1866 when the Paris Linguistic Society banned all papers on language’s beginnings. The Journal of Evolutionary Psychology is marking the Pinker-Bloom anniversary by devoting its December issue to the evolution of language. The introductory editorial, by Thomas Scott-Phillips, summarizes language origins in terms of interest to the evolutionary psychologist, making the editorial a handy guide to the differences between evolutionary psychology and evolutionary linguistics.

Hopefully I’ll have a post on Pinker and Bloom’s original paper, and how the field has developed over these last twenty years, at some point in the next couple of weeks. I think it’s historical importance will, to echo Bolles, be its value in opening up the field: with the questions of language origins and evolution turning into something worthy of serious intellectual investigation.

Other Links

Hypnosis reaches the parts brain scans and neurosurgery cannot.

Are Humans Still Evolving? (Part Two is here).

The Limits of Science.

On Language — Learning Language in Chunks.

Farmers, foragers, and us.

Tweet This.

On Music and The Brain.

Why I spoofed science journalism, and how to fix in.

The adaptive space of complexity.

A history of evolution pt. 2: The Wealth of Nations, Populations and On the Origin

Title page of the original edition of Malthus' 1798 work

Continue reading “A history of evolution pt. 2: The Wealth of Nations, Populations and On the Origin”

More on Phoneme Inventory Size and Demography

On the basis of Sean’s comment, about using a regression to look at how phoneme inventory size improved as geographic spread was incorporated along with population size, I decided to look at the stats a bit more closely (original post is here). It’s fairly easy to perform multiple regression in R, which, in the case of my data, resulted in highly significant results (p<0.001) for the intercept, area and population (residual standard error = 9.633 on 393 degrees of freedom; adjusted R-Squared = 0.1084). I then plotted all the combinations as scatterplots for each pair of variables. As you can see below, this is fairly useful as a quick summary but it is also messy and confusing. Another problem is that the pairs plot is on the original data and not the linear model.

Continue reading “More on Phoneme Inventory Size and Demography”

Theory of Mind and Language Evolution; What can psychopathology tell us?

Theory of Mind is the ability to infer other persons’ mental states and emotions. It is thought to have evolved as part of the human’s social brain and probably emerged as an adaptive response to increasingly complex primate social interaction.

Brüne and Brüne-Cohrs (2006) explore the ‘evolutionary cost’ of language evolution:

This sophisticated ‘metacognitive’ ability comes at an evolutionary cost, reflected in a broad spectrum of psychopathological conditions. Extensive research into autistic spectrum disorders has revealed that theory of mind may be selectively impaired, leaving other cognitive faculties intact. Recent studies have shown that observed deficits in theory of mind task performance are part of a broad range of symptoms in schizophrenia, bipolar affective disorder, some forms of dementia, ‘psychopathy’ and in other psychiatric disorders.

Now it’s fairly uncontroversial to assert that without the ability of theory of mind humans would have never evolved language (Sperber and Wilson, 2002). This is due to the fact that if one can’t attribute another to have a ‘mind’ like ones own, or assume that other minds hold different information to ones own then one would see little point in trying to share information. (I’m sorry for the amount of ‘ones’ in that sentence).

Sooo, it does not seem presumptuous to assume that people interested in the evolution of language should be interested in theory of mind, in fact for many years evolutionary linguists, psychologists and biologists have been looking into this, but mostly through observing the behaviour of animals, and especially primates to see if they display theory of mind capabilities. A good summary of this work can be found here, and a lot of relevant studies can be found on this blog in the What makes humans unique? posts by Michael. I’m not going to look at the animal data in this post, but instead what the deficiencies in some human conditions can tell us about the evolution of theory of mind. That is, what can autism, schizophrenia, bipolar affective disorder, dementia, ‘psychopathy’ and other psychiatric disorders tell us?

Continue reading “Theory of Mind and Language Evolution; What can psychopathology tell us?”

Language About Language

How is it, then, that we can talk about talking? If you are willing to assume the existence of basic perceptual and cognitive capacities, a relatively simple answer follows immediately. The sounds of talk are, after all, sounds like any other sounds. We can perceive them in the same way we perceive the sound of a waterfall or a bird’s song, a thunderclap or the rustling of leaves in the wind, a cricket’s chirp or the breaking of waves on a beach. All are things we can hear, easily and naturally, and so it is with the sound of the human voice.

Roman Jakobson famously theorized that language has six functions: referential, emotive, poetic, conative, phatic, and the metalingual function. That’s the function we’re interested in, our capacity to speak about speech. Jakobson talked of the metalingual function as an orientation toward the language code, which seems just a bit grand. For I’m led to believe that many languages lack terms for explicitly talking about the ‘code.’ Thus, in The Singer of Tales (Atheneum 1973, orig. Harvard 1960), Albert Lord attests (p. 25):

Man without writing thinks in terms of sound groups and not in words, and the two do not necessarily coincide. When asked what a word is, he will reply that he does not know, or he will give a sound group which may vary in length from what we call a word to an entire line of poetry, or even an entire song. [Remember, Lord is writing about oral narrative.] The word for “word” means an “utterance.” When the singer is pressed then to way what a line is, he, whose chief claim to fame is that he traffics in lines of poetry, will be entirely baffled by the question; or he will say that since he has been dictating and has seen his utterances being written down, he has discovered what a line is, although he did not know it as such before, because he had never gone to school.

While I’m willing to entertain doubts about the full generality of this statement – “man without writing” – I assume the it is an accurate report about the Yugoslavian peasants among whom Milman Parry and Albert Lord conducted their fieldwork and that it also applies to other preliterate peoples, though not necessarily to all.

Given those caveats, the paragraph is worth re-reading. Before doing so, recall how casually we have come to see language as a window on the workings of the mind in the Chomskyian and post-Chomskyian eras. If that is the case, then what can one see through a window that lacks even a word for words, that fails to distinguish between words and utterances? And what of the poets who don’t know what a line is? The lack of such knowledge does not stand in the way of the poeticizing, no more than the lack of knowledge of generative grammar precludes the ability to talk intelligently on a vast range of subjects.

Continue reading “Language About Language”

Language Evolution and Tetris!

Hello, people of the Blogosphere!

Why not take some time out from your dedicated reading to do a little language evolution experiment!  And all you have to do is play Tetris!

The Evolution of Tetris

… and learn an alien language.  It takes no more than 10 minutes.

The instructions and game are here:

http://blake.ppls.ed.ac.uk/~s0451342/tetris/Tetris_Experiment.htm

Due to me being a terrible programmer, it’ll probably crash or do some weird things.  But it’s all in the name of pseudo-science!

P.S. – users of the latest Firefox will need to update java.

Some Links #13: Universal Grammar Haters

Universal Grammar haters. Mark Lieberman takes umbrage with claims that Ewa Dabrowska’s recent work challenges the concept of a biologically evolved substrate for language. Put simply: it doesn’t. What their experiments suggest is that there are considerable differences in native language attainment. As some of you will probably know, I’m not necessarily a big fan of most UG conceptions, however, there are plenty of papers that directly deal with such issues. Dabrowska’s not being one of them. In Lieberman’s own words:

In support of this view, let me offer another analogy. Suppose we find that deaf people are somewhat more likely than hearing people to remember the individual facial characteristics of a stranger they pass on the street. This would be an interesting result, but would we spin it to the world as a challenge to the widely-held theory that there’s an evolutionary substrate for the development of human face-recognition abilities?

Remote control neurons. I remember reading about optogenetics awhile back. It’s a clever technique that enables neural manipulation through the use of light-activated channels and enzymes. Kevin Mitchell over at GNXP classic refers to a new approach where neurons are activated using a radio frequency magnetic field. The obvious advantage to this new approach being fairly straight-forward: magnetic-fields pass through brains far more easily than light. It means the new approach is a lot less invasive, without the need to insert micro-optical fibres or light-emitting diodes. Cool stuff.

Motor imagery enhances object recognition. Neurophilosophy has an article about a study showing that motor simulations may enhance the recognition of tools:

According to these results, then, the simple action of squeezing the ball not only slowed down the participants’ naming of tools, but also slightly reduced their accuracy in naming them correctly. This occured, the authors say, because squeezing the ball involves the same motor circuits needed for generating the simulation, so it interferes with the brain’s ability to generate the mental image of reaching out and grasping the tool. This in turn slows identification of the tools, because their functionality is an integral component of our conceptualization of them. There is other evidence that  parallel motor simulations can interfere with movements, and with each other: when reaching for a pencil, people have a larger grip aperture if a hammer is also present than if the pencil is by itself.

On the Origin of Science Writers. If you fancy yourself as a science writer, then Ed Yong, of Not Exactly Rocket Science, wants to read your story. As expected, he’s got a fairly large response (97 comments at the time of writing), which includes some of my favourite science journalists and bloggers. It’s already a useful resource, full of fascinating stories and bits of advice, from a diverse source of individuals.

Some thoughts about science blog aggregation. Although it’s still hanging about, many people, including myself, are looking for an alternative to the ScienceBlogs network. Dave Munger points to Friendfeed as one potential solution, with him setting up a feed for all the Anthropology posts coming in from Research Blogging. Also, in the comments Christina Pikas mentioned Nature Blogs, which, I’m ashamed to say, I haven’t come across before.

Cultural Diversity, Economic Development and Societal Instability

ResearchBlogging.orgMost of you in the science blogosphere have probably come across Razib’s recent post on linguistic diversity and poverty. The basic argument being that linguistic homogeneity is good for economic development and general prosperity. I was quite happy to let the debate unfold and limit my stance on the subject to the following few sentences I posted previously:

From the perspective of a linguist, however, I do like the idea of really obscure linguistic communities, ready and waiting to be discovered and documented. On the flip side, it is selfish of me to want these small communities to remain in a bubble, free from the very same benefits I enjoy in belonging to a modern, post-industrialised society. Our goal, then, should probably be more focused on documenting, as opposed to saving, these languages.

Since then, the debate has become a lot more heated, with Neuroanthropology wading in against Razib, which, in the second-half of the post at least, is worth reading just to get the general flavour of the other side in this debate. Having said that, I wasn’t convinced by the evidence Greg Downey used to dismiss Razib’s hypothesis, so I decided to actually look at the literature on the subject. The first paper I found upon searching was one by Nettle et al, in which they examine the relationship between cultural diversity and societal instability using a large cross-national data set of 212 nations. Importantly, they look at cultural diversity in the context of three areas: linguistically, ethnically and religious affiliation. Also, they draw a distinction between within-nation (alpha) diversity and between-nation (beta) diversity. Lastly, unlike other studies on the subject, where simple regression or correlation methods are used, the current study employs structural equation modelling (SEM):

Continue reading “Cultural Diversity, Economic Development and Societal Instability”