A bonus Friday talk by Prof. Nikolaus Ritt, who is visiting us from Vienna. “Modeling English word stress in terms of evolutionary game theory”, Friday 26th April, 4pm, DSB 1.17. Abstract below.

“Modeling English word stress in terms of evolutionary game theory”

The paper is assumes that a theory of cultural evolution, involving the iterated transmission of knowledge constituents, might not only explain the emergence of basic structural features of human language as such, but also underlies the historically transmitted properties of specific human languages. We therefore think that also the histories of specific languages can shed light on the principles on which cultural evolution works.

On the basis of this assumption the talk tries to account for the distribution of stress patterns in the English lexicon. We focus on the problem that – at least since the Norman Conquest and the influx of a large number of Romance loan words – English word stress has been quite variable in a rather unpredictable manner. Thus, we have ˈlentil but hoˈtel, ˈhonest but roˈbust and both ˈresearch_N and reˈsearch_N. Contrary to extant accounts in non-evolutionary frameworks, we do not derive stress patterns from the phonotactic structures of isolated lexical items, but regard them as emerging from the co-evolution of words (with segmental and syllabic structures) on the one hand, and rhythmic patterns on the other.

The basic idea is that words will assume lexical stress patterns that produce the best rhythmic patterns most of the time when they are expressed with one another in actual utterances. We model this in terms of evolutionary game theory. The players in our model are (disyllabic) words, and their strategies are the stress patterns they may assume (i.e initial stress or final stress). In each round of the game, two words meet (in one of a set of possible utterance contexts), choose stress patterns, and receive payoffs that reflect the well-formedness of the rhythmical structure their encounter produces. In our (rather abstract and simplified) model, the ideal rhythm is assumed to be strictly alternating and both stress clashes and lapses are seen as suboptimal. Applying standard methods of evolutionary game theory, we then calculate which distribution of stress patterns will come to be evolutionarily stable in the population of English words.

As will be seen, the model makes a few surprising predictions. Among the more interesting ones is that a mixed strategy will come to be stable among disyllabic items only if the lexicon contains a critical number of monosyllables. Even more interesting (actually to the extent of being suspicious) is that the evolutionary dynamics predicted by our model seems to fit the historical development of English word stress surprisingly well.

• «Previous Post
• Next Post »

---