Language and social structure

The Adventures of Auck has a great post today about the way languages change as more people begin to speak them. The post discusses several papers on the subject:

Last week saw the publication of Lupyan & Dale (2010) (also discussed here). It’s an analysis of languages from the World Atlas of Language Structures (WALS, quite fun to play around with), showing that languages spoken by more people tend to be less morphologically complex (fewer cases, fewer inflections, more of a tendency to express things using separate words rather than with morphology). It’s hypothesised that this is because a greater, more dispersed population will contain more second-language learners, therefore the language will tend to change to be easier to learn by adult learners, who seem to find morphology more difficult to learn than child learners.

This phenomenon has been noted before, but the Lupyan paperĀ  (citation below) goes into more detail than previous work, and provides a lot of evidence for language change in large speaker populations.

Then the post strays into even more interesting territory: does the same thing occur in animal populations? Isbell & Young propose that human evolution, and the growth in number of individuals in social groups (larger group sizes than other apes), may have led to greater complexity in communication systems, leading ultimately to what we might recognize as language. This seems to go against the hypothesis that smaller group size = greater syntactical complexity, but it is thought by some scientists that the development of larger social groups leads to greater intelligence, as individuals must be able to remember other members of the group, and navigate complex social alliances and hierarchies.

Smaller group size = greater complexity seems to apply to birdsong as well: Honda and Okanoya found in 1999 that the song of the domesticated finch is more complex than that of its wild descendants, incorporating more syllables and morphology.

Cool stuff. The three papers discussed are available via the links below, and make very interesting reading.

Lupyan G, Dale R (2010). Language Structure Is Partly Determined by Social Structure PLoS ONE, 5 (1) : 10.1371/journal.pone.0008559

Honda, E., & Okanoya, K. (1999). Acoustical and Syntactical Comparisons between Songs of the White-backed Munia (Lonchura striata) and Its Domesticated Strain, the Bengalese Finch (Lonchura striata var. domestica) Zoological Science, 16 (2), 319-326 DOI: 10.2108/zsj.16.319

Isbell, L. & Young (1996). The evolution of bipedalism in hominids and reduced group size in chimpanzees: alternative responses to decreasing resource availability Journal of Human Evolution, 30 (5), 389-397 DOI: 10.1006/jhev.1996.0034

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Hanging from the language tree

A recent issue of the Columbia Magazine has an article on Columbia professor Herb Terrace and his work on communication and cognition in chimpanzees. Terrace is best known for his role in the Nim Chimpsky experiments, which sought to settle the question of whether chimps could acquire human language.

From the article:

Terrace, a young Columbia psychologist who already had established himself as an expert in animal cognition, believed apes could learn to communicate, even think aloud, through sign language. All they needed, he thought, was a nurturing human- family environment.

At the time, the ape language wars were raging in academia. In one corner were the Chomskians, those who agreed with MIT linguist Noam Chomsky that only humans have innate syntactical ability. In the other were Skinnerians like Terrace who sided with Harvard psychologist B. F. Skinner, who believed that language is learned, and therefore could be taught to nonhuman primates.

Originally excited by the way that Nim Chimpsky (cheekily named after a certain venerable linguist) seemed to be able to produce real, novel sequences, Terrace came to realize that his evidence did not support that conclusion. In 1979, he published a paper in Science, publicly acknowledging that the Chomskians were right. “Apes can learn many isolated symbols (as can dogs, horses, and other nonhuman species),” Terrace wrote, “but they show no unequivocal evidence of mastering the conversational, semantic, or syntactic organization of language.”

Terrace continues to lecture and do research on cognition in primates. Although he does not believe that primates are capable of mastering the complexities of human language, he has a theory about how language acquisition might work. In keeping with the theory that language learning is highly tempered by environmental conditions, it has a lot to do with early intimate socialization:

Those who don’t get it, as was the case for thousands of Eastern European children orphaned during World War II, struggle to speak. The longer children are deprived of human interaction, the harder it is for them to talk. Terrace asks the question: if a baby were left on a deserted island with food and shelter, would it eventually on its own utter a word? The evidence suggests he wouldn’t.

This is the same problem autistic children face. Infants acquire language by watching their parents mouth sounds. Babies begin uttering monosyllabic words by the time they are about a year old. By 18 months, a child can point to an object, and name it: something he learns by following the eyes of his parent. Humans have a white sclera surrounding a dark iris, unlike all other animals, making it easy for babies to see where adults are looking. One of the early symptoms of autism is the inability of a baby to see where someone is pointing; instead, they often look at the gesturing hand.

It is clear that the acquisition of language has a profound effect on the way our minds function, and Terrace’s current research focuses on how animals can process information without the faculty so central to our own cognition.