Recently, David Burkett and Tom Griffiths have looked at iterated learning of multiple languages from multiple teachers (Burkett & Griffiths 2010, see my post here). Here, I’ll describe a simpler model which allows bilingualism. I show that, counter-intuitively, bilingualism may be more stable than monolingualism.
Tag: 10
Cultural Diversity, Economic Development and Societal Instability
Most 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):
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Some Links #10: Poo lady tweets shit
Gillian McKeith: You are what you tweet. If you thought the subject of my title was some five-year who just discovered various nouns for his excrement, then you’re not far off: Gillian McKeith is back, and like any bad-sequel she’s saying the same shit, just repackaged into an eerily similar set of events. What I particularly loved about this article is McKeith’s denial that she’s actually the McKeith in question. Confused? Head over and read the article. It’s short and fun.
A strong dose of regulation will keep the health food industry regular. Interesting article by Martin Robbins (of Lay Scientist) over at the Guardian. I’m not normally one for regulation: I think it’s often a backwards way of looking at an issue. And I’m definitely against our ridiculous zeal for legislation-only solutions. But I do think in the case of the health food industry regulation and legislation are fantastically effective. To bring it back to the post above: McKeith has literally made millions through the exploitation of a weakly controlled industry. Ultimately, though, I do think we need to also consider the other effective weapon against these erroneous claims: education. After all, those who know, know not to buy.
I Write Like… H.P. Lovecraft, apparently. It probably explains the lack of comments on my posts: people are scared shitless. It’s okay, I’m not a venomous wordsmith, just a former linguistics student searching for a new university to call home. See, not so scary now… Click the link if you fancy wasting a minute or so of your time.
The Price of Altruism. I always remember first learning about the Price equation at university, and the sad story of its progenitor, George Price, who committed suicide in 1975. Over a Gene Expression, Razib Khan has written a fantastic, in-depth review of Oren Harman’s book, The Price of Altruism. There are too many snippets of information to pick out for a summary, but here’s an ironically amusing section:
The “hawk” and “dove” morphs made famous by Richard Dawkins in The Selfish Gene go back to Maynard Smith’s work, but the terms themselves were of Price’s invention according to Harman. If I read Harman’s chronology correctly Price was already a fervent Christian by this time, having left atheism in the same period as he launched his career as an evolutionary biologist, and there is some hint that the term “dove” may have been influenced by his particular religious leanings. This possibility seems all the more amusing in light of Dawkins’ later career as an atheist polemicist.
Matt Ridley: When Ideas Have Sex. Love him for his biology, or loathe him for his economics, you can’t help but nod in agreement with Matt Ridley’s TED talk. I think he over emphasizes this apparent trend of good times to come. He clearly hasn’t read Taleb’s Black Swan (and probably isn’t all too interested given his risk-taking strategies at Northern Rock). But his stuff on trade and cultural evolution is fairly rock solid from my perspective.
Words as alleles: A null-model for language evolution?
For me, recent computational accounts of language evolution provide a compelling rationale that cultural, as opposed to biological, evolution is fundamental in understanding the design features of language. The basis for this rests on the simple notion of language being not only a conveyor of cultural information, but also a socially learned and culturally transmitted system: that is, an individual’s linguistic knowledge is the result of observing the linguistic behaviour of others. Here, this well-attested process of language acquisition, often termed Iterated Learning, emphasises the effects of differential learnability on competing linguistic variants. Sounds, words and grammatical structures are therefore seen to be the products of selection and directed mutation. As you can see from the use of terms such as selection and mutation it’s clear we can draw many parallels between the literature on language evolution and analogous processes in biology. Indeed, Darwin himself noted such similarities in the Descent of Man. However, one aspect evolutionary linguists don’t seem to borrow is that of a null model. Is it possible that the changes we see in languages over time are just the products of processes analogous to genetic drift?
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Can linguistic features reveal time depths as deep as 50,000 years ago?
Throughout much of our history language was transitory, existing only briefly within its speech community. The invention of writing systems heralded a way of recording some of its recent history, but for the most part linguists lack the stone tools archaeologists use to explore the early history of ancient technological industries. The question of how far back we can trace the history of languages is therefore an immensely important, and highly difficult, one to answer. However, it’s not impossible. Like biologists, who use highly conserved genes to probe the deepest branches on the tree of life, some linguists argue that highly stable linguistic features hold the promise of tracing ancestral relations between the world’s languages.
Previous attempts using cognates to infer the relatedness between languages are generally limited to predictions within the last 6000-10,000 years. In the present study, Greenhill et al (2010) decided to examine more stable linguistic features than the lexicon, arguing:
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The story of Jeremy and his magic magnets
Note: Before reading this post, you should pop over to the Independent and read this shocking piece of journalism by Jeremy Laurance: Magnet’s can improve Alzheimer’s symptoms. Then, read the scientific report in question: Improved language performance in Alzheimer disease following brain stimulation. I found myself asking how Mr Laurance could have come up with this, and reached the following conclusion…
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Population size predicts technological complexity in Oceania
Here is a far-reaching and crucially relevant question for those of us seeking to understand the evolution of culture: Is there any relationship between population size and tool kit diversity or complexity? This question is important because, if met with an affirmative answer, then the emergence of modern human culture may be explained by changes in population size, rather than a species-wide cognitive explosion. Some attempts at an answer have led to models which make certain predictions about what we expect to see when populations vary. For instance, Shennan (2001) argues that in smaller populations, the number of people adopting a particular cultural variant is more likely to be affected by sampling variation. So in larger populations, learners potentially have access to a greater number of experts, which means adaptive variants are less likely to be lost by chance (Henrich, 2004).
Models aside, and existing empirical evidence is limited with the results being mixed. I previously mentioned the gradual loss of complexity in Tasmanian tool kits after the population was isolated from mainland Australia. Elsewhere, Golden (2006) highlighted the case of isolated Polar Inuit, who lost kayaks, the bow and arrow and other technologies when their knowledgeable experts were wiped out during a plague.Yet two systematic studies (Collard et al., 2005; Read, 2008) of the Inuit case found no evidence for population size being a predictor of technological complexity.
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The Movius Line represents the crossing of a demographic threshold
When examining the dispersal of Pleistocene hominins, one of the more fascinating debates concern the patterns of biological and technological evolution in East Asia and other regions of the Old World. One suggestion emerging from palaeoanthropological research places a demarcation between these two regions in the form of a geographical division known as the Movius Line. Specifically, the suggestions that initially led to the Movius Line were based on observations of differing technological patterns, namely: the lack of Acheulean handaxes and the Levallois core traditions in East Asia.
Since Hallam L. Movius’ initial proposal, the recent discovery of handaxes within East Asia have led to suggestions that the Movius Line is in fact obsolete. Suggesting this may not in fact be the case is a recent paper by Stephen Lycett & Christopher Norton, which highlights three central points coming from a growing body of research: 1) “several morphometric analyses have identified statistically significant differences between the attributes of specific biface assemblages from east and west of the Movius Line”; 2) “The number of sites from which handaxes have been recovered in East Asia tend to be geographically sparse compared with many regions west of the Movius Line”; 3) “‘handaxe’ specimens tend only to comprise a small percentage of the total number of artefacts recovered, a situation that contrasts with many classic Acheulean sites in western portions of the Old World, where bifacial handaxes may dominate assemblages in large numbers”.
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Cumulative Culture Evolved to Rapidly Coordinate Novel Behaviours
In the deliberations over humanity and its perceived uniqueness, a link is frequently made between our ability to support a rich, diverse culture and the origin of complex human behaviour. Yet what is often overlooked in our view of these two, clearly connected phenomena is the thread that weaves them together: the ability to coordinate behaviour. We need only look at the products of our culture, from language to religion, to see that any variant we may deem successful is contingent on coordinating the behaviour of two or more individuals. Still, what is truly illuminating about this ability is that, far from being a uniquely human feature, the ability to coordinate behaviour is ubiquitous throughout the many organismal kingdoms.
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Guns, Germs and Predictable Reviews
If, like me, you generally like the Guardian’s science features, then please avoid reading Tim Radford‘s book club discussion of Jared Diamond‘s Guns, Germs and Steel. Ever since I noticed this book was on the Guardian’s reading list, it’s been an ongoing curiosity of mine as to how they will tackle the subject. Mainly because Diamond’s book, along with Richard Dawkins’ The Selfish Gene, urged me to move into studying evolution. Sadly, and perhaps not very surprisingly, you get little from the discussion bar an unequivocal acceptance of Diamond’s central thesis: that of environmental determinism.
Nowhere is there a mention of ideas that stand somewhat in opposition to Diamond’s, such as those in the 10,000 Year Explosion. Namely, the consequences of agriculture on recent human evolution, and the growing mountain of evidence supporting the contention that different human populations have adapted to their local environments.
And just to be clear: I think Diamond’s book is a well-written, scholarly account of human history, and it’s influence is not to be understated. But I also think he overlooked a large portion of the argument.