Imitate that one: dolphins spontaneously interpret human pointing gesture in a novel context

Abstract

Understanding whether non-human animals interpret human pointing as cooperative communication remains a central question in comparative cognition. Pointing is a foundational aspect of human communication, yet success in traditional object-choice tasks could theoretically reflect conditioned responses rather than comprehension of communicative intent. Recent work therefore focuses on testing flexible, spontaneous use of gestures in novel contexts. Here, we examined whether bottlenose dolphins (Tursiops truncatus) could interpret a human point to solve a new problem in a modified “do-as-I-do” task: selecting which of two conspecific models to imitate. Subjects (n = 3) were already proficient in imitating a single model. In this version, they observed two models simultaneously performing different behaviors while the trainer gave the signal to imitate and pointed to one model. To succeed, dolphins had to interpret the point as indicating which model to imitate. All dolphins performed significantly above chance, both in overall imitation accuracy (chance = 1/11) and when analysis was limited to trials in which they imitated one of the two models (chance = ½). Performance did not improve across trials, indicating spontaneous rather than learned interpretation. These findings demonstrate that non-language-trained dolphins can flexibly apply the meaning of a familiar gesture in a novel context, responding to the same gesture with different behaviors by spontaneously interpreting the meaning of the gesture within the new game. This interpretation suggests an understanding of pointing as cooperative communication rather than a simple discriminative cue, paralleling results in dogs and raising the possibility that dolphins’ abilities evolved through self-domestication and/or conspecific distal referencing systems such as echolocation.