Human–dog interactions are a great way to demonstrate what I call the behaviour of language: that is, a fundamental difference between human and nonhuman communication and, consequently, between human and nonhuman cognition.
Imagine a situation in which your dog is barking and whining at you (signals) because it wants an item of food that only you can reach. According to this study, the dog’s communicative behaviour is intentional and referential, since the animal tries to get your attention, its gaze alternates between you and the food, and it persists when it does not achieve its goal, for example.
Now, imagine that you swap roles with the dog. This is harder to imagine because we are normally not dependent on dogs for food or other basic needs. However, like the dog, you would find yourself producing signals, such as a pointing gesture and the sentence ‘Hey, bring me that food over there!’ Your behaviour can also be said to be intentional and referential (even if a little embarrassing) because it includes attention-getting, gaze alternation, elaboration and all the other criteria used in the above study. However, unless your dog is trained, you will probably not get the food and be quite frustrated.
This frustration reveals that human-style communication has to do with some kind of control over the receiver that other animals do not have. At some point in our evolutionary past, our ancestors must have developed this kind of control before they had the opportunity to develop elaborate signals requiring so much attention from a receiver—especially when the receiver was not domesticated or captive in an experimental lab.
Indeed, getting a human to bring you food is similar to training a dog to fetch: you do not simply persist in the hope that the human—who probably has better things to do—understands and wants to cooperate. Rather, you offer them an incentive to make such an effort, such as reciprocal help. To this end, the ability to exert physical control over a domesticated and loyal receiver obviously helps.
Prescription
The dog in the above study wants you to get the food, but does not aim at you as a receiver of signals. The dog merely tries to get you to react to the situation. (Saying that the dog gets you to respond would confuse the situation or the food stimulus with signals. For coherence, we should say that animals react to stimuli and respond to signals.)
The dog’s signalling is ‘descriptive’ because it refers to a state of reality, e.g. ‘I am here’, ‘there is food over there’, ‘I want it’. The dog’s behaviour reflects a certain intention, but its signals come after the intention; they are only a means to an end.
By contrast, as humans, we seek the dog’s responses to gestures and spoken words as an end in themselves. This means that our signalling is prescriptive, i.e. our signals come before the associated intention of fetching an object such as food. (The word ‘prescribe’ comes from the Latin prae-scribere meaning ‘write before’.) Unlike the dog, we try to establish a signal–response relationship whereby a certain expression or gesture will make a cooperative dog get something for us. The dog cannot do the same with us.
In light of this analysis, it may be clear why I call prescriptive signalling the behaviour of language. The reason why you can speak with a human or, to some extent, with a dog is that these receivers stick around in the first place. They do not go away or ignore signals like other animals do. Dogs are attuned to us after thousands of years of prescriptive interactions. They ‘know’ that they will be rewarded for paying attention to your signals and figuring out what you mean. As I argued in my original paper Prescription: A biological definition of language, this explains why our theory of mind and complex expressions such as ‘Hey, bring me that food over there!’ evolved only in humans.
Cognitive evolution and language
Most theorists and researchers focus erroneously on cognition when trying to explain why humans evolved to have language and symbolic culture. They feel that the dog’s communicative efforts are meaningful, like a language. This anthropomorphism motivates them to study dogs’ and apes’ ability to share meaning or information with us. To quote the same study, the authors are interested in whether the ‘dog’s behaviors are based on simple mechanisms or on a theory of mind about their owners’.
This is a comfortable position to have. If researchers could establish that the dog ascribes mental states to a human (theory of mind), then this would fit nicely in the current neo-Darwininan picture of human origins. We could speak of human-like communication in dogs and apes, if not memes and language. We could picture our ancestors as evolving naturally to be companions and understand spoken instructions, rather than seeing this as a result of domestication and human intention, which is perhaps unsettling. Natural selection, rather than artificial selection and training, would have shaped the dog’s ability to connect its mind with our, as it were, and share mental representations of food and play.
This means, however, that any animal could potentially begin to communicate like we do, provided that the required socio-cognitive environment ‘evolved’. Imagine, for instance, a dog who began to bark about food for the mere sake of informing others, or about food not immediately present. Imagine this ‘food’ does not even exist, but the dog insists that others respond. Imagine that the dog begins to combine these calls to refer to an indefinite number of foods he would like to taste, and so on.
Of course, we have already imagined these things in the form of myth and storytelling. Yet, these and other exclusive features of language appear to exist only in humans, who happen to be the only animals that prescribe. Only humans can train dogs to fetch or get frustrated with children who do not behave as told. This involves an ability to use signals primarily to command action and, secondarily, to refer to an object. The referent does not need to be present. The referent ‘food’ is a concept that the signaller may or may not apply to a perceived object and that cannot be shared with species that do not prescribe, no matter how much their minds may connect with ours.
(More information about the cognitive aspects of prescription can be found in my original research paper.)