Non-verbal effecting - animal research sheds light on human emotion communication.

Cracking the non-verbal "code" of human emotions has been a chief interest of generations of scientists. Yet, despite much effort, a dictionary that clearly maps non-verbal behaviours onto meaning remains elusive. We suggest this is due to an over-reliance on language-related concepts and an under-appreciation of the evolutionary context in which a given non-verbal behaviour emerged. Indeed, work in other species emphasizes non-verbal effects (e.g. affiliation) rather than meaning (e.g. happiness) and differentiates between signals, for which communication benefits both sender and receiver, and cues, for which communication does not benefit senders. Against this backdrop, we develop a "non-verbal effecting" perspective for human research. This perspective extends the typical focus on facial expressions to a broadcasting of multisensory signals and cues that emerge from both social and non-social emotions. Moreover, it emphasizes the consequences or effects that signals and cues have for individuals and their social interactions. We believe that re-directing our attention from verbal emotion labels to non-verbal effects is a necessary step to comprehend scientifically how humans share what they feel.