Annual Review of Psychology 2012

The Annual Review of Psychology for the year 2012 is now available. From a language evolution/evolution of human cognition point of view, there are two articles that look particularly interesting:

"Mechanisms of Social Cognition by Chris D. Frith and Uta Frith"

"Social animals including humans share a range of social mechanisms that are automatic and implicit and enable learning by observation. Learning from others includes imitation of actions and mirroring of emotions. Learning about others, such as their group membership and reputation, is crucial for social interactions that depend on trust. For accurate prediction of others' changeable dispositions, mentalizing is required, i.e., tracking of intentions, desires, and beliefs. Implicit mentalizing is present in infants less than one year old as well as in some nonhuman species. Explicit mentalizing is a meta-cognitive process and enhances the ability to learn about the world through self-monitoring and reflection, and may be uniquely human. Meta-cognitive processes can also exert control over automatic behavior, for instance, when short-term gains oppose long-term aims or when selfish and prosocial interests collide. We suggest that they also underlie the ability to explicitly share experiences with other agents, as in reflective discussion and teaching. These are key in increasing the accuracy of the models of the world that we construct."

The Evolutionary Origins of Friendship by Robert M. Seyfarth and Dorothy L. Cheney

Social animals including humans share a range of social mechanisms that are automatic and implicit and enable learning by observation. Learning from others includes imitation of actions and mirroring of emotions. Learning about others, such as their group membership and reputation, is crucial for social interactions that depend on trust. For accurate prediction of others' changeable dispositions, mentalizing is required, i.e., tracking of intentions, desires, and beliefs. Implicit mentalizing is present in infants less than one year old as well as in some nonhuman species. Explicit mentalizing is a meta-cognitive process and enhances the ability to learn about the world through self-monitoring and reflection, and may be uniquely human. Meta-cognitive processes can also exert control over automatic behavior, for instance, when short-term gains oppose long-term aims or when selfish and prosocial interests collide. We suggest that they also underlie the ability to explicitly share experiences with other agents, as in reflective discussion and teaching. These are key in increasing the accuracy of the models of the world that we construct.

Accent Forecasts in the UK and Germany

Yesterday I watched the second episode of Stephen Fry's four-part documentary series Planet Word which dealt with Identity and also had a short tidbit about Linguistic Relativity featuring an interview with Lera Boroditsky (although I must say that as a native speaker of German I'm still quite puzzled that I apparently tend to associate feminine attributes with bridges because they have feminine gender in German ("Die Brücke" ), whereas Spanish speakers associate male attributes with bridges because they have male gender in Spanish (el puente).

I also liked Stephen Fry's "Accent Forecast" for the UK

However, I wonder whether he was inspired by this German sketch

Update: Two (again quite negative) reviews of this episode, one by linguist Pauline Foster and one by syntactican Manuela Rocchi can be found here and here

4th Birthday!

Today marks the 4th Birthday of this Blog, and although I haven't managed to post anything in quite a while, I thought I'd use this happy occasion to point out some interesting links:

First, James Hurford's sequel to his 2007 "The Origins of Meaning" has finally been published:

With, 808 pages "The Origins of Grammar"is twice as long as his 2007 volume and consists of three parts. To quote from the book description:

"The book is divided into three parts. In the first the author surveys the syntactic structures evident in the communicative behaviour of animals, such as birds and whales, and discusses how vocabularies of learned symbols could have evolved and the effects this had on human thought. In the second he considers how far the evolution of grammar depended on biological or cultural factors. In the third and final part he describes the probable route by which the human language faculty and languages evolved from simple beginnings to their present complex state."

An almost 100-page-long sample chapter, dealing with the question whether non-human animals have syntax, can be found here. In this chapter, Hurford analyses the structure of whale song, bird song, and primate calls, and comes to the conclusion that:

"No non-human has any semantically compositional syntax, where the form of the syntactic combination determines how the meanings of the parts combine to make the meaning of the whole."

Second, in the first part of a 5-part documentary series on language, Stephen Fry explores the evolution of language. Although there are some minor quibbles (e.g. Stephen Fry stating that language arose from primates grunts about 50,000 years ago, and him speculating that "it really is" language that makes us different from other primates without anyone to back him up), it's a thoroughly enjoyable documentary featuring interviews with people like Steven Pinker, and Michael Tomasello and Wolfgang Enard (of FOXP2-fame) at the Max-Planck-Institute for Evolutionary Anthropology.

Hat tip: */ˈdɪːkæf/

Update: Sean of Replicated Typo points to a pretty detailed (and pretty harsh) critique over at badlinguistics

Communication in Bonobos, Chimpanzees, and the Evolution of Language

The current issue of First Language features some interesting articles on the evolution of language:

It includes a book review of Michael Tomasello's "Origins of Human Communication" by Evan Kidd as well as a review of an edited volume titled "The Evolution of Human Language: Biolinguistic Perspectives" by Thomas Scott-Phillips, who rightly argues that the term Biolinguistics - which is mainly used by people from the Generative Grammar camp - is "not a theory-neutral term for the study of language origins."

Last but not least, there's also an interesting article by Heidi Lyn, Patricia Greenfield and E. Sue Savage-Rumbaugh about "Semiotic combinations in Pan: A comparison of communication in a chimpanzee and two bonobos."

Here's the abstract:

Communicative combinations of two bonobos (Pan paniscus) and a chimpanzee (Pan troglodytes) are compared. All three apes utilized ordering strategies for combining symbols (lexigrams) or a lexigram with a gesture to express semantic relations such as agent of action or object of action. Combinatorial strategies used by all three apes revealed commonalities with child language, spoken and signed, at the two-year-old level. However, many differences were also observed: e.g., combinations made up a much smaller proportion and single symbols a much larger proportion of ape production compared with child production at a similar age; and ape combinations rarely exceeded three semiotic elements. The commonalties and differences among three sibling species highlight candidate combinatorial capacities that may underlie the evolution of human language.

Power and Perspective Taking

From Perlman & Miller (2009):

Powerful people are not very good at comprehending other people's point of view and taking their perspective: "If you ask powerful people to quickly drawn an "E" on their foreheads, they are much more likely than people of low power to draw the letter as if they were reading it, which makes it backward and illegible for anyone else - like this:"∃ " (Galinsky et al. 2006)"

On The Human: Terrence Deacon - Rethinking The Natural Selection Of Human Language

I just stumbled across this interesting website called "On The Human." Its

"an online community of humanists and scientists dedicated to improving our understanding of persons and the quasi-persons who surround us. As persons are biological, psychological, historical, moral, and autobiographical beings, we employ modes of inquiry from the sciences and humanities. Contributors explore issues in metaphysics and biology, ethics and neuroscience, experimental philosophy and evolutionary psychology."

Anyway, there are some interesting articles at the interface of Cognitive Science, Evolution, and Language on the site, written by quite well-known researchers, and what's even more interesting is that there are often comments by other researchers. For example, there's an article by Terrence Deacon called Rethinking The Natural Selection Of Human Language which features a lively discussion including, among others, Mark Turner, Talmy Givón, Derek Bickerton, Sue Savage-Rumbaugh and Salikoko Mufwene.

There's also an article by Sue Savage-Rumbaugh called "Human Language - Human Consciousness", which focuses on her work with enculturated bonobos like Kanzi, Panzi and Panbanisha and also includes a very heated discussion of her claims.

Review of FOXP2 and its role in brain development, speech, and the evolution of language

Edmund Blair Bolles over at Babel's Dawn discusses a very interesting review of "FOXP2 and the role of cortico-basal ganglia circuits in speech and language evolution" by Wolfgang Enard. Be sure to check it out!

Below you can find the abstract of the review:

"Purpose of the review

A reduced dosage of the transcription factor FOXP2 leads to speech and language impairments probably owing to deficits in cortical and subcortical neural circuits. Based on evolutionary sequence analysis it has been proposed that the two amino acid substitutions that occurred on the human lineage have been positively selected. Here I review recent studies investigating the functional consequences of these two substitutions and discuss how these first endeavors to study human brain evolution can be interpreted in the context of speech and language evolution.

Recent findings

Mice carrying the two substitutions in their endogenous Foxp2 gene show specific alterations in dopamine levels, striatal synaptic plasticity and neuronal morphology. Mice carrying only one functional Foxp2, show additional and partly opposite effects suggesting that FOXP2 has contributed to tuning cortico-basal ganglia circuits during human evolution. Evidence from human and songbird studies suggest that this could have been relevant during language acquisition or vocal learning, respectively.

Summary

FOXP2 could have contributed to the evolution of human speech and language by adapting cortico-basal ganglia circuits. More generally the recent studies allow careful optimism that aspects of human brain evolution can be investigated in model systems such as the mouse.

Highlights

► First functional studies investigate human FOXP2 evolution in a mouse. ► Human-specific properties of FOXP2 are specific to cortico-basal ganglia circuits. ► These properties might be relevant for language acquisition and/or vocal learning."

Terrence Deacon - Incomplete Nature: How Mind Emerged from Matter

It looks like Terrence Deacon, famed author of The Symbolic Species: The Co-evolution of Language and the Brain (1997), the second most cited text in the Language Evolution and Computation Bibliography has a new book out in November this year called "Incomplete Nature: How Mind Emerged from Matter". I don't know to what extent this book will have anything interesting to say about the evolution of language per se, but as it seems to focus on the evolution of cognition, it certainly looks like its well worth a read.

Here's the book description:

A radical new explanation of how life and consciousness emerge from physics and chemistry.

Leading biological anthropologist and neuroscientist Terrence W. Deacon, whose acclaimed book The Symbolic Species explained how the human brain evolved its capacity for language, now offers a radical new approach to the riddle of consciousness. The fact that minds emerged from life and life emerged from inanimate matter leads Deacon to reexamine this mystery from the bottom up. While the same kinds of atoms make up rivers, bacteria, and human brains, Deacon shows how their dynamical relationships produce their different properties. In Incomplete Nature he reveals a missing link: emergent processes that are neither fully mental nor merely material, which provide a bridge connecting the two. He demonstrates how functions, intentions, representations, and values-despite their apparent nonmaterial character-can nevertheless produce physical consequences. Origins of life, information, sentience, meaning, and free will all fall into place in a fully integrated scientific account of the relationship between mind and matter.

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 very 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 “influencing” and “shaping” something an bee 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.

Different manifestations of the idea of linguistic relativity

Language as Language-of-Thought

In its most extreme form, thought is simply equated with language. But this view, in which the units of thought are simply words from natural language, clearly can’t be right. For example, we can have thoughts that are difficult to express, we can understand ambiguous expressions (like “Kids make nutritious snacks”), and we are able to coin new words that express new meanings. All this would not be possible if we didn’t have a more fine-grained mental representation that that is encoded in words. In addition, research on non-human primates and human infants suggests that they are capable of some sophisticated forms of thought even in the absence of language.

This line of reasoning points to a representational format for concepts, categorization, memory, and reasoning that is separate from language.

On a very general level, then, we can all agree that thought is separate from language. But what about the many different ways language can affect thought?

Here, we can first make a distinction between views that hold that language determines thought (linguistic determinism), and those that hold that there are structural differences between language and thought, but that, nevertheless, language influences the way we think.

Linguistic Determinism

Linguistic determinism, a position most often connected to the name of Benjamin Lee Whorf, separates language from the conceptual system, but holds that the language we speak determines the basic categories of thought. This influence is seen as so strong that it can even overwrite pre-existing perceptual and categories in a way analogous to the way infants lose the ability to notice phonetic distinctions that do not exist in their native language. For example, at 6 months, infants growing up in English-speaking households are able to discriminate sounds that in Hindi are seen as different but in English are not, but at 12 months they have lost this ability and only pay attention to sound distinctions relevant to English (e.g. Dirven et al. 2007).

The linguistic determinism-hypothesis poses that this process also holds for many other areas of perception and, critically, cognition. To quote Whorf:

“The world is presented in a kaleidoscopic flux of impressions which have to be organized largely by the linguistic systems in our minds.”

“We cut up nature—organize it into concepts—and ascribe significances as we do, largely because of absolutely obligatory patterns of our own language.”

(Please note that in most of his writings, Whorf actually argues for a position that is much more sophisticated and subtle than the one expressed in these popular quotes)

If language is given the role of organizing “the kaleidoscopic flux of impressions” presented to us by the world, this means that on this view, there is a very tight connection between what we can call the conceptual system/thought, and language, one the one hand, and a very loose connection between the conceptual system/thought and the world on the other.

A lot of research in the cognitive sciences, however, indicates that the relationship between thought and the world is much tighter than is assumed in linguistic determinism. For example, languages differ in the way they talk about motion events, especially in the way they encode the direction or path of a motion, on the one hand, and the manner of motion on the other:

"Manner languages (e.g.,English, German, Russian, and Mandarin Chinese) typically code manner in the verb(cf. English skip, run, hop, jog), and path in a variety of other devices such as particles (out), adpositions (into the room), verb prefixes (e.g.,German raus- ‘out’; cf. raus-rennen ‘run out’), etc. Path languages(e.g.,Modern Greek, Romance, Turkish, Japanese, and Hebrew) typically code path in the verb (cf. Greek vjeno ‘exit’, beno ‘enter’, ftano ‘arrive/reach’,aneveno ‘ascend’, diashizo ‘cross’), and manner in adverbials(trehontas‘running’, me ta podia ‘on foot’, grigora ‘quickly’)." (Papafragou & Selimis 2010: 227)

However, studies by Anna Papafragou and others suggest that although, say, English and Spanish speakers talk differently about the same motion event, the still remember it similarly:

"both manner and path seem to be available to an equal extent to speakers of different languages for purposes of (non-linguistic) categorisation and memory, regardless of whether these components are prominently and systematically encoded in the language." (Papafragou & Selimis 2010: 229)

These results and other experiments suggesting that in some respects 'thought and language' are less well aligned than 'thought and world' of course pose a serious problem for linguistic determinism.

Other Ways Language Might Have an Effect on Thought

In sum, this means that two versions of the Sapir-Whorf-Thesis – the Language-as-Thought and Linguistic Determinism hypotheses – can be rejected. But this still leaves us with the many ways language can have an effect on thought.

As Wolff & Holmes note it is precisely because" language and the conceptual system differ that we might expect a tension between them, driving each system to exert an influence on the other."

Wolff & Holmes use 5 different metaphors to classify the ways this can happen.

1. Thinking for speaking: Language influences thinking when we think about how to express something in language immediately prior to speaking
2. Language as meddler: linguistic representations/language and non-linguistic representations/thought can conflict and compete with each other
3. Language as augmenter: Language enables or extends certain kinds of thought
4. Language as spotlight: Language directs attention to /makes certain aspects very salient in thinking
5. Language as inducer: Language can be seen as a primining mechanisms that induces certain ways of thinking about something

In my next post, I’ll elaborate on these 5 subclasses of how language might affect thought.

[Cross posted at Replicated Typo]

References:

Dirven, René, Hans-Georg Wolf and Frank Polzenhagen (2007): "Cognitive Linguistics and Cultural Studies." In: Dirk Geeraerts und Hubert Cuyckens (Hrsg.): The Oxford Handbook of Cognitive Linguistics. Oxford: Oxford University Press, 1203-1221.

Papafragou, Anna and Stathis Selimis (2010): "Event categorisation and language: A cross-linguistic study of motion." In: Language and Cognitive Processes 25: 224-260.

Wolff, P., & Holmes, K. (2011). Linguistic relativity Wiley Interdisciplinary Reviews: Cognitive Science, 2 (3), 253-265

How do children learn the difference between 'laying' and 'standing' a bottle on a table in Tamil, Dutch (and other languages)?

From the current issue of the Journal of Child Language: "The role of input frequency and semantic transparency in the acquisition of verb meaning: evidence from placement verbs in Tamil and Dutch" by Bhuvana Narasimhan and Marianne Gullberg
Here's the abstract:

We investigate how Tamil- and Dutch-speaking adults and four- to five-year-old children use caused posture verbs (‘lay/stand a bottle on a table’) to label placement events in which objects are oriented vertically or horizontally. Tamil caused posture verbs consist of morphemes that individually label the causal and result subevents (nikka veyyii ‘make stand’; paDka veyyii ‘make lie’), occurring in situational and discourse contexts where object orientation is at issue. Dutch caused posture verbs are less semantically transparent: they are monomorphemic (zetten ‘set/stand’; leggen ‘lay’), often occurring in contexts where factors other than object orientation determine use. Caused posture verbs occur rarely in Tamil input corpora; in Dutch input, they are used frequently. Elicited production data reveal that Tamil four-year-olds use infrequent placement verbs appropriately whereas Dutch children use high-frequency placement verbs inappropriately even at age five. Semantic transparency exerts a stronger influence than input frequency in constraining children's verb meaning acquisition.

The relation between pointing and language development

The December 2010 issue of 'Developmental Review' features a nice meta-analysis of of studies on pointing and language development by Cristina Colonnesia, Geert Jan J.M. Stamsa, Irene Kostera, and Marc J. Noomb. Here's their abstract and their 'research highlights'

Abstract

The use of the pointing gesture is one of the first ways to communicate with the world. This gesture emerges before the second year of life and it is assumed to be the first form of intentional communication. This meta-analysis examined the concurrent and longitudinal relation between pointing and the emergence of language. Twenty-five studies were included into the meta-analysis, including 734 children. The role of several moderators was examined: pointing modality, pointing motive, age at which the pointing was measured, the assessment method of the pointing gesture and language development, the modality of language, SES, and country. The results showed both a concurrent (r = .52) and a longitudinal (r = .35) relation between pointing and language development.

The relation between pointing and language development became stronger with age, and was found for pointing with a declarative and general motive, but not for pointing with an imperative motive. It is concluded that the pointing gesture is a key joint-attention behavior involved in the acquisition of language.

Research highlights

► Pointing gesture is concurrently (r = .52) and longitudinally (r = .35) related to language development. ► The relation between pointing gesture and language becomes stronger with age, in particular during the end of the second year of life. ► Both the production (r = .33) and the comprehension (r = .38) of pointing gesture are related to language development. ► Pointing with a declarative (r = .39) and with a general motive (r = .39), rather than with an imperative motive (r = .04), are related to language.

The need for multimodality in primate communication research

Barbara King points to a very interesting article in press at Animal Behaviour. In their essay "The language void: the need for multimodality in primate communication research" Katie Slocombe, Bridget Waller and Katja Liebal analyse more than 550 studies on primate communication from 1960 to 2008 and argue that research in one modality (e.g. gesture) often differs so strongly in its methodology from research on another modality (e.g. alarm calls) that the results can hardly be reliably compared. Here's their abstract:

Theories of language evolution often draw heavily on comparative evidence of the communicative abilities of extant nonhuman primates (primates). Many theories have argued exclusively for a unimodal origin of language, usually gestural or vocal. Theories are often strengthened by research on primates that indicates the absence of certain linguistic precursors in the opposing communicative modality. However, a systematic review of the primate communication literature reveals that vocal, gestural and facial signals have attracted differing theoretical and methodological approaches, rendering cross-modal comparisons problematic. The validity of the theories based on such comparisons can therefore be questioned. We propose that these a priori biases, inherent in unimodal research, highlight the need for integrated multimodal research. By examining communicative signals in concert we can both avoid methodological discontinuities as well as better understand the phylogenetic precursors to human language as part of a multimodal system.

Barbara King's discussion of the article is also very illuminating.

John Hawks: How language eats brains, and why it matters to language evolution.

John Hawks has posted a fascinating discussion of a new paper published in the Proceedings of the National Academy of Sciences (here) by Bedny et al. that shows that in congenitally blind adults, "brain regions that are thought to have evolved for vision can take on language processing as a result of early experience." (to quote from the abstract) (see also John Lehrer's discussion, here)

These results show the brain's immense plasticity, especially in early development. Crucially, the fact that "brain regions that did not evolve for language can nevertheless participate in language processing" (Bedny et al.) poses the questions whether language-specific processing functions need to have evolved at all.

To quote from John Hawk's discussion at lenght:

"The blind subjects tell us that the ground for language processing is almost as fertile elsewhere in the cortex. Many brain areas have the genetic equipment to recruit and organize neurons into useful circuits for language processing. Language development is developmentally robust because it can rely on a rich language environment, not because of genetic standardization. The basic problems of language evolution must be explained by showing how robust language communities emerged. I don't preclude genetics, far from it -- weaker language environments may have become stronger because of evolutionary change. But that evolution must have been substantially domain-general, because language processing is not specifically canalized by genetics.

I like this scenario because it means we shouldn't be looking for lots of language-specific genetic changes in the last few hundred thousand years. The Neandertal genome suggests that there may not have been any at all"

To me, these results also seem compatible with arguments made by Morten Christiansen, Nick Chater, and others, who argue that language was shaped by the human brain and its learning and processing mechanisms, instead of there being a language-specific biological endowment. On this view, then "language evolution is a process of cultural change, in which linguistic structures are shaped through repeated cycles of learning and use by domain-general mechanisms" (Chater & Christiansen 2010).

UPDATE [21/03/11]: John Hawks has written another highly interesting post that is also relevant to this topic and the question of the evolution of language and cognition more generally: The development of sharing and cooperation from infancy to school-age and (here).

The Linguistics of Birdsong - Review in Trends in Cognitive Sciences

In the current issue of Trends in Cognitive Sciences there is an interesting (and free!) review of the linguistics of birdsong and its similarities and differences to human language:

Unlike our primate cousins, many species of bird share with humans a capacity for vocal learning, a crucial factor in speech acquisition. There are striking behavioural, neural and genetic similarities between auditory-vocal learning in birds and human infants. Recently, the linguistic parallels between birdsong and spoken language have begun to be investigated. Although both birdsong and human language are hierarchically organized according to particular syntactic constraints, birdsong structure is best characterized as ‘phonological syntax’, resembling aspects of human sound structure. Crucially, birdsong lacks semantics and words. Formal language and linguistic analysis remains essential for the proper characterization of birdsong as a model system for human speech and language, and for the study of the brain and cognition evolution.

Robert C. Berwick, Kazuo Okanoya, Gabriel J.L. Beckers and Johan J. Bolhuis (2011) "Songs to syntax: the linguistics of birdsong." In: Trends in Cognitive Sciences." Volume 15, Issue 3, March 2011, Pages 113-121

Update: Edmund Blair Bolles of Babel's Dawn has also just published a very short article about human speech, birdsong and convergent evolution in the journal Bioscience (here)

Four Stone Hearth 112, Chimpanzees, Hosts, and Goats

The latest edition of the Four Stone Hearth #112 is out over at Anthropology in Practice and contains a number of very interesting links.

For example, they link to a very interesting post by Barbara J. King in which she discusses work by David Leavens, Timothy P. Racine, and William D. Hopkins about pointing behaviour in chimpanzees. These authors question claims made by people like Michael Tomasello and others that only humans point declaratively to provide information and share attention (something which I blogged about previously, e.g. here; see also this post and a very interesting post about a new article by Hopkins and colleagues at Babel's Dawn)

Also, Four Stone Hearth is in dire need of hosts so please check out its announcement page if you might be interested in hosting it.

Hat tip: Daniel Lende

P.S. on a lighter note Anthropologists Trace Human Origins Back To One Large Goat

Patricia Kuhl: The linguistic genius of babies | Video on TED.com

Patricia Kuhl: The linguistic genius of babies | Video on TED.com

"At TEDxRainier, Patricia Kuhl shares astonishing findings about how babies learn one language over another -- by listening to the humans around them and "taking statistics" on the sounds they need to know. Clever lab experiments (and brain scans) show how 6-month-old babies use sophisticated reasoning to understand their world."

Can children learn abstract syntactic principles by using general cognitive capacities?

One of the most hotly debated issues in the study of language acquisition is whether the abstract syntactic principles of a language can be learned by children

1. by using domain-general capacities (such as pattern finding, analogy, statistical learning, categorization and generalization, etc.)

or whether they need

2. innately specified knowledge of language that enables them to form the right abstract syntactic categories that cannot be infered from the surface level of linguistic utterances (Chomsky's Poverty of Stimulus Argument)

In a new paper in the journal Cognition, Perfors et al. (2011) argue that domain-general capacities are sufficient for children to be able to learn abstract syntactic principles inherent in the linguistic input.

Here's the abstract:

Children acquiring language infer the correct form of syntactic constructions for which they appear to have little or no direct evidence, avoiding simple but incorrect generalizations that would be consistent with the data they receive. These generalizations must be guided by some inductive bias – some abstract knowledge – that leads them to prefer the correct hypotheses even in the absence of directly supporting evidence. What form do these inductive constraints take? It is often argued or assumed that they reflect innately specified knowledge of language. A classic example of such an argument moves from the phenomenon of auxiliary fronting in English interrogatives to the conclusion that children must innately know that syntactic rules are defined over hierarchical phrase structures rather than linear sequences of words (e.g., [Chomsky, 1965], [Chomsky, 1971],[Chomsky, 1980] and [Crain and Nakayama, 1987]). Here we use a Bayesian framework for grammar induction to address a version of this argument and show that, given typical child-directed speech and certain innate domain-general capacities, an ideal learner could recognize the hierarchical phrase structure of language without having this knowledge innately specified as part of the language faculty. We discuss the implications of this analysis for accounts of human language acquisition.

'Evolution and Human Behavioural Diversity'

The February issue of the Philosophical Transactions of the Royal Society B: Biological Sciences looks very interesting: It is a theme issue called 'Evolution and human behavioural diversity' and was compiled and edited by Gillian R. Brown, Thomas E. Dickins, Rebecca Sear and Kevin N. Laland. It consists of 13 articles and an introduction, which are all available for free.

Here's the abstract of the introduction:

Human beings persist in an extraordinary range of ecological settings, in the process exhibiting enormous behavioural diversity, both within and between populations. People vary in their social, mating and parental behaviour and have diverse and elaborate beliefs, traditions, norms and institutions. The aim of this theme issue is to ask whether, and how, evolutionary theory can help us to understand this diversity. In this introductory article, we provide a background to the debate surrounding how best to understand behavioural diversity using evolutionary models of human behaviour. In particular, we examine how diversity has been viewed by the main subdisciplines within the human evolutionary behavioural sciences, focusing in particular on the human behavioural ecology, evolutionary psychology and cultural evolution approaches. In addition to differences in focus and methodology, these subdisciplines have traditionally varied in the emphasis placed on human universals, ecological factors and socially learned behaviour, and on how they have addressed the issue of genetic variation. We reaffirm that evolutionary theory provides an essential framework for understanding behavioural diversity within and between human populations, but argue that greater integration between the subfields is critical to developing a satisfactory understanding of diversity.

The article that looks most interesting to me is a paper by W. Tecmuseh Fitch called "Unity and diversity in human language":

Human language is both highly diverse—different languages have different ways of achieving the same functional goals—and easily learnable. Any language allows its users to express virtually any thought they can conceptualize. These traits render human language unique in the biological world. Understanding the biological basis of language is thus both extremely challenging and fundamentally interesting. I review the literature on linguistic diversity and language universals, suggesting that an adequate notion of ‘formal universals’ provides a promising way to understand the facts of language acquisition, offering order in the face of the diversity of human languages. Formal universals are cross-linguistic generalizations, often of an abstract or implicational nature. They derive from cognitive capacities to perceive and process particular types of structures and biological constraints upon integration of the multiple systems involved in language. Such formal universals can be understood on the model of a general solution to a set of differential equations; each language is one particular solution. An explicit formal conception of human language that embraces both considerable diversity and underlying biological unity is possible, and fully compatible with modern evolutionary theory.