The evolution of language: a comparative review

For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

Timing of pitch movements and perceived vowel duration

The hypothesis was tested that the timing of accent-lending pitch movements influences the perceived duration of a vowel. Dutch subjects were asked to adjust the physical duration of a vowel so as to fit into the temporal structure of a sentence. The vowel occurred in a monosyllabic word embedded in a carrier sentence. Three pitch movements on the vowel were used, a rise, a rise-fall, and a fall. Two opposite trends were found: the earlier the fall, the longer the duration of the target vowel was adjusted, the earlier the rise or rise-fall, the shorter its duration was adjusted. Control experiments indicated that the results should be interpreted in terms of a trade-off between the effects on prominence of timing of pitch movements and physical segment duration. It is concluded that late timing of pitch movements enhances the perceived vowel duration, but that this effect depends on the kind of pitch movement: the effect is cancelled in the case of late rises and rise-falls, whereas it is enhanced in the case of late falls by virtue of the enhancing effect on prominence of the accented syllable