A new essay by Simone Pika and three of her colleagues titled "Taking turns: bridging the gap between human and animal communication" published in the journal Royal Society B: Biological Sciences along with some mass media summaries including "You talking to me? Scientists try to unravel the mystery of 'animal conversations'" caught my eye because they cover an important aspect of social communication, namely, cooperative turn-taking, and how this pattern of conversing might be related to the evolution of human language. The piece by the researchers is available online, so here are a few thoughts about what they write.

Dr. Pika and her colleagues provide examples of turn-taking in birds, mammals, insects, and anurans (tailless amphibians). They write, "the extent to which cooperative turn-taking is uniquely human or represents a homologous (by shared inheritance) and/or analogous (by parallel evolution) trait is currently unknown." They then summarize what we know about cooperative turn-taking in various taxa and define turn-taking as "the orderly exchange of purely communicative signals or behaviours (e. . peek-a-boo games in humans) between individuals characterized by principles for the coordination of turn transfer, which result in observable temporal regularities."

Cooperative turn-taking during social play is essential for the maintenance of the play mood

What caught my eye in their discussion of turn-taking in mammals (cetaceans, bats, elephants, and mole rats) was the absence of a discussion of cooperative turn-taking during social play behavior by dogs and other nonhuman animals (animals). Here, I'll focus on dogs, because many dogs love to play and the dynamics of canine social play have been studied in considerable detail (for more discussion please see Canine Confidential: Why Dogs Do What They Do and many references therein).

Source: Marc Bekoff

When we carefully study the landscape of play, we learn that dogs know very well how to tell other dogs “I want to play with you.” They use a number of different actions to signal their desire to play. These include bowing, face pawing, approaching and rapidly withdrawing, faking left and going right, mouthing, and running right at a potential playmate. Bows also can be used to tell another dog, “I’m sorry I bit you so hard, let’s keep playing.”

Bows are highly stereotyped movements and essentially are contracts to play. They change the meaning of the actions that follow, such as biting and mounting and serve to reinitiate play after there’s a pause in the action. Bows also allow dogs to perform a wide variety of different actions as they spring up after bowing.

Dogs and other animals know they must “play fair” for play to work, so bigger, stronger, and more dominant dogs hold back through role-reversing and self-handicapping. These trade-offs help to maintain fair play. Role-reversing occurs when a dominant animal performs an action during play that would not normally occur during real . For example, a dominant or higher-ranking dog would not roll over on their back during fighting, but they will do so while playing.

The basic rules that dogs and other animals follow when they play are: Ask first, be honest, follow the rules, and admit when you're wrong. When the rules of play are violated and when fairness breaks down, so too does play. Dogs keep track of what is happening when they play and fairness is the name of the game. They can read what other dogs are doing, and they trust that they want to play rather than fight. Because there is a lot of thinking and feeling "on the run," social play also is a good place to study Theory of Mind (ToM) in other animals (for more discussion please see "Theory of Mind and Play: Ape Exceptionalism Is Too Narrow," "The Power of Play: Dogs Just Want to Have Fun," and links therein). Each player needs to pay close to what the other dog has done and is doing, and each uses this information to predict what the other is likely to do next.

Detailed analysis of videos of dogs at play show that exchanging intentions to play and maintaining the play mood involve cooperative turn-taking. Being able to converse in this way can also explain why vigorous rough-and-tumble play only rarely escalates into real fighting. The players know what they're doing. They aren't confused when they agree to play with one another (for further discussion please see "Rough‐and‐tumble play as a window on animal communication").

The comparative turn-taking framework and the importance of comparative research of how animals converse with one another

Dr. Pika and her colleagues conclude, "Overall, direct comparisons of turn-taking skills of non-human animals in relation to language origins (but also social communication and communication in general) are highly constrained by lack of data, the application of different terms, methodological designs (observational versus experimental paradigms) and study environments (captivity versus natural environments)."

The addition of social play behavior to examples of cooperative turn-taking not only adds a new social context to the discussion, but also adds new species in which these sorts of conversations likely take place.

Toward the end of their excellent essay, Dr. Pika and her colleagues offer a new framework for studying cooperative turn-taking. The four elements include:

Flexibility of turn-taking organization.

Who is taking the next turn?

When do response turns occur?

What should the next turn do?

This new comparative framework can readily be used "to spur more research into this research domain and to test which elements of the human turn-taking system are shared across species and taxa." Social play and many other social situations readily lend themselves to these sorts of analyses.

Dr. Pika and her colleagues have made a very thoughtful and important contribution to the comparative study of social communication, and I look forward to further discussions of data collected on diverse animals. What an exciting time it is to conduct research on patterns of social communication in other animals and what's happening in their very active minds as they exchange information on the go.