Humans are born imitators. The ability to imitate others comes naturally to us and plays a major role in how we learn about the world. But imitation is not widespread in the animal kingdom. True imitation, which goes beyond merely mimicking another's behavior to include purposeful intention, is rare.

Dolphins are one of the few animals that can truly imitate. In 2010, researchers at the Dolphin Research Center (DRC) in Grassy Key, Florida, showed dolphins can imitate behaviors without using their eyesight. Dolphins were trained on a "do-as-I-do" game, in which a model (in this case another dolphin) performed a specific behavior and the target dolphin was asked to imitate it. A young male dolphin named Tanner was able to imitate the model dolphin's behaviors even when he was "blindfolded" — fitted with soft, latex eyecups that completely blocked his sight.

Now, a follow-up study shows not only how Tanner accomplished this task using sound, but also that he used a deliberate, problem-solving approach to imitation. The research was published in the journal Animal Cognition.

Kelly Jaakkola, lead author on the two papers and Director of Research at DRC, suspected Tanner was using sound to imitate, but there were two possibilities: "He could have recognized the characteristic sound the behavior makes, just like you or I might recognize the sound of hands clapping, or he could have used echolocation to "see" the behavior with sound," she says.

In the follow-up study, Jaakkola and her team changed how the behaviors sounded by using a human model instead of a dolphin. Like the dolphin model, the human model performed a variety of motor behaviors including bobbing up and down, spinning in a circle, and swimming like a fish with legs and feet moving side-to-side. A person moving in the water sounds very different from a dolphin moving in the water. With the sound changed, would Tanner still be able to recognize the behavior to copy it?

Jaakkola and her colleagues showed Tanner had no problem imitating the human model using sound alone. But even more interesting was how he used sound. Tanner switched strategies when imitating a dolphin and a human. Specifically, when he imitated a human blindfolded, he produced many more echolocation clicks than when he had imitated a dolphin blindfolded. "When he had been imitating the familiar-sounding dolphin behavior, he just recognized the characteristic sound of the behavior," Jaakkola says. "But when we gave him the less familiar sound of a human doing the behavior, he switched to using echolocation."

Dolphin Research Center, Grassy Key, FL

This is the first demonstration of flexibility in using a new perceptual route to imitation in any non-human animal. Not only did Tanner use a new perceptual route, he switched strategies depending on the situation. He was flexible enough to seek new information, change strategies, and change his approach to the task. Jaakkola says this shows he wasn't just copying "mindlessly," but was instead engaged in imitation as an intentional, problem-solving process.

These experiments demonstrate dolphins can recognize and imitate trained behaviors, but Jaakkola is also interested in investigating spontaneous imitation in problem-solving situations. So far, all dolphin imitation studies have used the "do-as-I-do" procedure where the dolphin is specifically asked to imitate a learned behavior. But in the real world, much of the value of imitation comes from observing how others solve problems and then spontaneously adopting their technique. The DRC team hopes to probe dolphins' abilities to imitate novel behaviors and look into whether dolphins spontaneously use imitation to learn from each other in more natural situations.

Such experiments would not only shed light on the dolphin mind, but the evolution of imitation, as well. Since true imitation is so rare in the animal kingdom, it is likely that the ability evolved separately in humans and dolphins. Learning how dolphins use their imitation skills could provide insight into why they, and humans, became imitating animals at all.

References:

Jaakkola, K., Guarino, E., and Rodriguez, M. (2010). Blindfolded imitation in a bottlenose dolphin (Tursiops truncatus). International Journal of Comparative Psychology 23: 671-688.

Jaakkola, K., Guarino, E., Rodriguez, M., and Hecksher, J. (2013). Switching strategies: A dolphin's use of passive and active acoustics to imitate motor actions. Animal Cognition 16(5): 701-709. doi: 10.1007/s10071-013-0605-3