Toward inclusive theories of the evolution of musicality

Abstract

We compare and contrast the 60 commentaries by 109 authors on the pair of target articles by Mehr et al. and ourselves. The commentators largely reject Mehr et al.'s fundamental definition of music and their attempts to refute (1) our social bonding hypothesis, (2) byproduct hypotheses, and (3) sexual selection hypotheses for the evolution of musicality. Instead, the commentators generally support our more inclusive proposal that social bonding and credible signaling mechanisms complement one another in explaining cooperation within and competition between groups in a coevolutionary framework (albeit with some confusion regarding terminologies such as “byproduct” and “exaptation”). We discuss the proposed criticisms and extensions, with a focus on moving beyond adaptation/byproduct dichotomies and toward testing of cross-species, cross-cultural, and other empirical predictions.

Neuroecological selection for musical features through spatial reciprocity in long-term partnerships

“…Thus musicality seems to run the full gamut of associations from those involving infant care, to mate bonding, to intra- and inter-group signaling. I therefore concur with efforts to develop a broad and inclusive theory where signaling and bonding theories can coexist under one framework (Savage et al ., 2021). Others have argued that this spectrum is actually U-shaped from mother infant to pair to group (Lehmann, Welker and Schiefenhövel, 2009), more akin to what I have attempted to do above from a mostly signaling perspective.…”

“…On the opposite extreme, some have claimed that human music is entirely unique. Despite claims that animal musicality and singing has no homology or analogy with human forms (Hauser and McDermott, 2003; Savage et al ., 2021), the data suggest otherwise. I have shown elsewhere (Schruth, 2020) that musicality (as measured via ARDI) has a strong evolutionary signal (lambda∼0.8) evidencing a deep homology in primates.…”

“…And while I continue to argue for higher brain processing of such signals in a way that facilitates higher-order pro-sociality (e. Despite the recent fnding that rhythmicity tends to decrease as group sizes grow larger across primate species (Schruth, 2022), there is something alluringly inviting about a (highly conspicuous ) instrumental rhythmic performance. Other researchers have noted that metrical rhythm is easy for an outsider to join (Savage et al, 2021). I have recently noted that there even appears to be more room for additional performers beyond the typical small-family spectralperformance of gibbons, to something on the order of six individuals, in more rhythmically-inclined species (Schruth 2022).…”

“…Since the resurgence of ideas in the origins of music, many others have clamored onto this line of thought. Recent ideas on the function of music include equalization of emotional states, reinforcing of emotional coordination and promotion of conjoinment (Dissanayake, 2009), managing social uncertainty, facilitating affiliative and pro social interaction (Cross, 2011), coordinating affect for social identity, cooperation and alliance building (Bryant, 2013), increasing value through emotional contagion, social cohesion, improved well being (Snowdon, Zimmermann and Altenmüller, 2015), and thinking of it as vocal and kinesthetic communication of social emotional content (Morley, 2014), as well as stress reduction by reduction of costs of group living (Savage et al ., 2021).…”

Vocal imprecision as a universal constraint on the structure of musical scales

“…The harmonies emerging from these textures may have shaped musical scales beyond the simple melody-based forms that we studied here. Hence, we view Interval Spacing theory as a fundamental theory of the origin of musical scales, one that can be used to build models of musical tonality 40 and the cultural evolution of music 41,42 .…”