title: Yawn contagion in humans and bonobos: emotional affinity matters more than species.
abstract: In humans and apes, yawn contagion echoes emotional contagion, the basal layer of empathy. Hence, yawn contagion is a unique tool to compare empathy across species. If humans are the most empathic animal species, they should show the highest empathic response also at the level of emotional contagion. We gathered data on yawn contagion in humans (Homo sapiens) and bonobos (Pan paniscus) by applying the same observational paradigm and identical operational definitions. We selected a naturalistic approach because experimental management practices can produce different psychological and behavioural biases in the two species, and differential attention to artificial stimuli. Within species, yawn contagion was highest between strongly bonded subjects. Between species, sensitivity to others' yawns was higher in humans than in bonobos when involving kin and friends but was similar when considering weakly-bonded subjects. Thus, emotional contagion is not always highest in humans. The cognitive components concur in empowering emotional affinity between individuals. Yet, when they are not in play, humans climb down from the empathic podium to return to the "understory", which our species shares with apes.
authors.affiliation: Natural History Museum, University of Pisa , Pisa , Italy ; Institute of Cognitive Sciences and Technologies, Unit of Cognitive Primatology & Primate Center , CNR, Rome , Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Palagi
authors.affiliation: Natural History Museum, University of Pisa , Pisa , Italy.
authors.forename: Ivan
authors.initials: I
authors.lastname: Norscia
authors.affiliation: Natural History Museum, University of Pisa , Pisa , Italy ; Bioscience Department, University of Parma , Parma , Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Demuru
keywords: Affective empathy; Cognitive empathy; Cross-species comparison; Emotional contagion; Homo sapiens; Pan paniscus