The Association Between the Bared-Teeth Display and Social Dominance in Captive Chimpanzees ().

Unlabelled: Humans use smiles - widely observed emotional expressions - in a variety of social situations, of which the meaning varies depending on social relationship and the context in which it is displayed. The homologue of the human smile in non-human primates - both due to morphological and functional similarities - is the bared-teeth display (BT). According to the power asymmetry hypothesis (PAH), species with strict linear dominance hierarchies are predicted to produce distinct communicative signals to avoid escalations of social conflicts.

Bared-teeth displays in bonobos (Pan paniscus): An assessment of the power asymmetry hypothesis.

Facial expressions are key to navigating social group life. The Power Asymmetry Hypothesis of Motivational Emancipation predicts that the type of social organization shapes the meaning of communicative displays in relation to an individual's dominance rank. The bared-teeth (BT) display represents one of the most widely observed communicative signals across primate species.