Referential and Affective Communication

When we think of human language, we often emphasize its referential properties: words make reference to external objects or events; speakers provide semantic information to listeners. By contrast, most 19th and 20th-century scientists described animal communication systems as exclusively affective, viewing the vocalizations of nonhuman animals as reflexive expressions of the signaler’s emotional state. Thus a sharp distinction was drawn between referential signaling and affective signaling. Seyfarth and Cheney (2003) argue that this dichotomy is false and obfuscatory. In their view, it is wrong to treat animal signals as either referential or affective, because the two properties are independent.

A signal's referential properties concern its relation to features of the environment. Whether a call can serve as a referential signal depends on the specificity of call production, determined by its informative value (the strength of the association between the call and its eliciting stimulus) and by its referential specificity (the breadth of eliciting stimuli). A signal's affective properties, on the other hand, concern the underlying mechanism by which that relation arises.

As Seyfarth and Cheney point out, the mechanism that leads to the association between a signal and an external event or object does not affect a signal's potential to inform others. An affective signal could be elicited by such a broad array of stimuli that it provides a listener with only vague information, or an affective signal could be informative and referentially specific and thus provide a listener with specific information. Likewise, a referential signal could be caused by a signaler's emotions, or a referential signal could be produced independently of the signaler's emotions.

For instance, baboons' grunts vary in their amplitude and repetition according to their informative value, whether they are indicating group movement (high referential specificity) or a more general, friendly social interaction (low referential specificity). Both of these types of grunts also vary acoustically according to the communicator's affective arousal, so that their informative and affective value may both be encoded together in the grunt's unique acoustic properties.