Social Origins of Rhythm? Synchrony and Temporal Regularity in Human Vocalization

Abstract

Humans have a capacity to perceive and synchronize with rhythms. This is unusual in that only a minority of other species exhibit similar behavior. Study of synchronizing species (particularly anurans and insects) suggests that simultaneous signal production by different individuals may play a critical role in the development of regular temporal signaling. Accordingly, we investigated the link between simultaneous signal production and temporal regularity in our own species. Specifically, we asked whether inter-individual synchronization of a behavior that is typically irregular in time, speech, could lead to evenly-paced or ''isochronous'' temporal patterns. Participants read nonsense phrases aloud with and without partners, and we found that synchronous reading resulted in greater regularity of durational intervals between words. Comparison of same-gender pairings showed that males and females were able to synchronize their temporal speech patterns with equal skill. These results demonstrate that the shared goal of synchronization can lead to the development of temporal regularity in vocalizations, suggesting that the origins of musical rhythm may lie in cooperative social interaction rather than in sexual selection.

Rhythm in speech and animal vocalizations: a cross‐species perspective

“…The human ability to spontaneously synchronize to music and to simpler rhythmic stimuli contrasts with the lack of evidence on spontaneous motor synchronization in spoken utterances (though see Refs. and ). Yet, there is some evidence that the accent structure of rhythmical speech, as found in, for example, children's poetry, can entrain movement even when participants are not explicitly instructed to move to speech .…”

Synchrony as an Adaptive Mechanism for Large‐Scale Human Social Bonding

“…Ryder et al 2011). This might form part of the origins of synchronised activities (Merker et al 2009), but the lack of clear sexual dimorphism in human abilities for synchronisation suggests that this is unlikely to be the only purpose that these activities serve (Bowling et al 2013). Merker 2000).…”

Regularity in speech rhythm as a social coalition signal

“…However, it is not yet clear whether the emission of a periodic signal that facilitates entrainment and synchrony is an adaptive signal in nonhuman species, or is a byproduct of affiliative prosocial behavior that is perceived by the nonspecifics, but is not controlled by the signaling individual . In humans, on the other hand, synchrony has been claimed to be an adaptive signal of cooperation . All periodic patterns, that is, isochronous sequences of events, are rhythmic, but the reverse is not always true .…”

“…Speech production is a kind of motor activity, and the main articulatory movement is the mandibular oscillation that builds the syllable frame, or vocalization frame . Temporal regularity of mandibular cycles enables predicting the onset of the following syllable and facilitates joint actions, like chorusing, moving together, or adjusting motor output to the acoustic input and thus interindividual motor actions . The tendency toward isochrony at the syllabic timescale can be driven by the urge to coordinate vocalizations and movements between individuals .…”