Communication accommodation theory : a dolphin perspective

Abstract

For humans, there is a well-established theory, which explains much of the variation in human verbal dyadic speech behavior, the “communication accommodation theory (CAT)”. In its most basic form, CAT predicts that as two conversation partners become more similar in their speech patterns, the more likely they are to perceive the interaction, and/or the other person favorably. In this exploration of CAT in a non-human mammal, I look for the cornerstones of the theory in bottlenose dolphin communication. Dolphins depend largely on acoustic communication to maintain ever-changing social interactions in a marine environment. Dolphins have individually specific signature whistles that allow them to broadcast their identity, and also are able to encode additional information across those whistle emissions. They often use these whistles in antiphonal exchanges with other dolphins. In Chapter 2, I show that dolphins use signature whistles more often when conspecifics are present, suggesting a socially mediated system for signature whistle use. I find that male allies do not converge their signature whistles from pre-alliance to alliance formation, as previously suggested, nor over the course of alliance (Chapter 3). I do find that allies have more similar signature whistles to their male partner than to non-allies and in Chapter 4, find that male allies subtly accommodate during antiphonal signature whistle exchanges. During experimental playbacks of manipulated whistles to a bottlenose dolphin, I recorded subtle parameter accommodation in the frequency pitch shifts from one unit of a signature whistle playback to the next, suggesting that even when there is no difference in reinforcement, dolphins have the propensity for accommodation during signature whistle interactions. This thesis presents the first suggestion that the CAT may be a good model for the study for animal communication systems moving forward.