LEC talk Tuesday 27 October: Simon Kirby

By jon | October 23, 2015

Tuesday 27 October, 11:00–12:30
Room 1.17, DSB

Simon Kirby (work with Tessa Verhoef and Carol Padden, UCSD)

Naturalness and Systematicity: Evidence from artificial sign language

Language is shaped by cognitive biases. These biases can influence the emergence of linguistic structure through multiple linking mechanisms: improvisation of novel solutions to communicative tasks; repeated interaction between communicating individuals; and iterated learning of linguistic conventions over multiple generations. The study of language evolution seeks an explanation of the origin of linguistic structure in terms of these processes and their interaction with human cognition.

In this talk I will concentrate on two types of bias that shape the emergence of linguistic structure: naturalness, and systematicity. Both are the result of a domain general preference for simplicity, but differ in how this simplicity is realised. Naturalness is a property of the relationship between linguistic form and something non-linguistic, whereas systematicity is a property of the relationship among linguistic elements. I will argue that the former type of bias is felt most strongly during improvisation, whereas the latter is felt most strongly during learning.

To test this, we look at a formal feature that governs the lexicon of sign languages: the so-called instrument vs. handling distinction. This has been recently argued to exhibit “patterned iconicity”, a property that combines both naturalness and systematicity. We show in series of artificial sign language experiments online and in the lab that even participants who have never been exposed to sign languages are sensitive to this feature. We show a very strong naturalness bias for instrument forms to be matched with objects and handling forms to be matched with actions. However, the naturalness bias that favours an iconic relationship between form and meaning can be overturned after a small number of exposures to an anti-iconic artificial sign language. This shows that although naturalness may be important in the early stages of language emergence, it is systematicity that is the driving factor where sets items are being learned and transmitted.