The Indexical Voice: Communication of Personal States and Traits in Humans and Other Primates

Abstract

Many studies of primate vocalization have been undertaken to improve our understanding of the evolution of language. Perhaps, for this reason, investigators have focused on calls that were thought to carry symbolic information about the environment. Here I suggest that even if these calls were in fact symbolic, there were independent reasons to question this approach in the first place. I begin by asking what kind of communication system would satisfy a species’ biological needs. For example, where animals benefit from living in large groups, I ask how members would need to communicate to keep their groups from fragmenting. In this context, I discuss the role of social grooming and “close calls,” including lip-smacking and grunting. Parallels exist in human societies, where information is exchanged about all kinds of things, often less about the nominal topic than the communicants themselves. This sort of indexical (or personal) information is vital to group living, which presupposes the ability to tolerate, relate to, and interact constructively with other individuals. Making indexical communication the focus of comparative research encourages consideration of somatic and behavioral cues that facilitate relationships and social benefits, including cooperation and collaboration. There is ample room here for a different and potentially more fruitful approach to communication in humans and other primates, one that focuses on personal appraisals, based on cues originating with individuals, rather than signals excited by environmental events.

Vocal modulation in human mating and competition

“…In the 1997 film 'Contact,' scientists detect an extraterrestrial signal containing 63 000 pages of undecipherable data originating from the star system Vega and later discover that embedded within this signal is a second, hidden message necessary for decoding the data. In recent decades, it has become increasingly evident that the acoustic features of our voices similarly comprise a second message embedded within our spoken communication, a message that can add to, modulate, or even negate the literal meaning of our speech [8,9,86]. We are beginning to decode this message, discovering that voice conveys information about a speaker's traits, such as age, sex, dominance and physical condition (e.g.…”

“…From a developmental perspective, the capacity to formulate vocal expression and inflection is evident early in life and is seen when infants babble [7]. These critical elements are not necessarily learned [8,9], although older children can effectively be taught to improve their ability to use vocal expression and volume to enhance communication skills [10]. Some of the human capacity to modulate acoustic features of vocalizations, such as f o , is also shared with a number of non-human primates (e.g.…”

From emotional signals to symbols

“…This fact was even noted briefly in the article that first presented the claim about semantics in vervet monkey calls ( Seyfarth et al, 1980 ). The confusions about alarm calls are placed in historical perspective in two additional articles in this Frontiers Topic ( Locke, 2021 ; Rendall, 2021 ).…”