Regularity in speech rhythm as a social coalition signal
Date
2019Author
Polyanskaya, Leona
Samuel, Arthur G.
Ordin, Mikhail
Metadata
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Polyanskaya, L. , Samuel, A. G. and Ordin, M. (2019), Regularity in speech rhythm as a social coalition signal. Ann. N.Y. Acad. Sci., 1453: 153-165. doi:10.1111/nyas.14193
Abstract
Regular rhythm facilitates audiomotor entrainment and synchronization in motor behavior and vocalizations
between individuals. As rhythm entrainment between interacting agents is correlated with higher levels of cooperation
and prosocial affiliative behavior, humans can potentiallymap regular speech rhythmonto higher cooperation
and friendliness between interacting individuals.We tested this hypothesis at two rhythmic levels: pulse (recurrent
acoustic events) and meter (hierarchical structuring of pulses based on their relative salience).We asked the listeners
to make judgments of the hostile or collaborative attitude of two interacting agents who exhibit either regular
or irregular pulse (Experiment 1) or meter (Experiment 2). The results confirmed a link between the perception of
social affiliation and rhythmicity: evenly distributed pulses (vowel onsets) and consistent grouping of pulses into
recurrent hierarchical patterns are more likely to be perceived as cooperation signals. People are more sensitive to
regularity at the level of pulse than at the level of meter, and they are more confident when they associate cooperation
with isochrony in pulse. The evolutionary origin of this faculty is possibly the need to transmit and perceive
coalition information in social groups of human ancestors. We discuss the implications of these findings for the
emergence of speech in humans.