Singing showed higher pitch, slower tempo and greater stability compared to conversation, and is associated with greater social bonding: A Registered Report replicating and extending Ozaki et al. (2024) with (NZ) English Speakers

Scientists have long debated the evolutionary functions of music and language. The Music and Social Bonding hypothesis proposes that music is particularly effective for strengthening cohesion in large groups because acoustic features that characterise song facilitate synchrony and promote social bonding. Ozaki and colleagues (2024) showed that singing exhibited a higher pitch, a slower temporal rate, and higher pitch stability, but their reliance on experienced musicians and a solo-singing format limited generalizability of their findings. This Registered Report compared singing with speaking within a single experimental paradigm, examining the relationship between group singing and conversation in Aotearoa New Zealand among 23 English-speaking participants. We analysed three acoustic features (pitch height, pitch stability, and temporal rate) and explored pre- and post-experiment changes in self-reported social bonding. Relative to conversation, singing showed higher pitch (d = 0.81, P = .0007, n=20), slower temporal rate (d = 1.14, P < 1x10-9, n=20), and more stable pitch (d = 0.23, P = .006, n=20), replicating Ozaki et al.’s (2024) acoustic findings in a New Zealand English group context. Exploratory analyses suggested that social bonding increased more after singing (49% increase, n=8) than after conversation (26%, n=7) or lyric recitation (4%, n=8), though these results are tentative pending comparison with more global data. Our findings add support for acoustic and behavioral differences between song and speech, and highlight directions for future large-scale tests of the Music and Social Bonding hypothesis.