Contrary to spontaneous yawning, which is widespread in vertebrates and probably evolutionary ancient, contagious yawning—yawning triggered by others’ yawns—is considered an evolutionarily recent phenomenon, found in species characterized by complex sociality. Whether the social asymmetry observed in the occurrence of contagious yawning is related to social and emotional attachment and may therefore reflect emotional contagion is a subject of debate. In this study we assessed whether yawn contagion was enhanced in pregnant women, a cohort of subjects who develop prenatal emotional (...) attachment in preparation for parental care, via hormonal and neurobiological changes. We predicted that if yawn contagion underlies social and emotional attachment, pregnant women would be more likely to contagiously yawn than nonpregnant, nulliparous women of reproductive age. We gathered data in two different settings. In the experimental setting, 49 women were exposed to video stimuli of newborns either yawning or moving their mouth and we video-recorded the women during repeated trials to measure their yawning response. In the naturalistic setting, 131 women were observed in a social environment and their yawning response was recorded. We tested the factors influencing the yawning response, including the reproductive status. In both settings, yawn contagion occurred significantly more in pregnant than nonpregnant women. By showing that pregnant women were most likely to respond to others’ yawns, our results support the hypothesis that the social variation observed in yawn contagion may be influenced by emotional attachment and that yawning in highly social species might have been coopted for emotional contagion during evolution. (shrink)

Automatic behavioral matching includes Rapid Facial Mimicry (RFM) and Yawn Contagion (YC) that occur when the facial expression of an individual acts as a ‘mirror social releaser’ and induces the same facial expression in the observer (within 1 s for RFM, and minutes for YC). Motor replication has been linked to coordination and emotional contagion, a basic form of empathy. We investigated the presence and modulating factors of Rapid Smile Mimicry (RSM) and YC in infants/toddlers from 10 to 36 months (...) at the nursery ‘Melis’ (Turin, Italy). In February-May 2022, we gathered audio and/or video of all occurrences data on affiliative behaviors, smiling during play, and yawning during everyday activities. Both RSM and YC were present, as toddlers were most likely to smile (within 1 s) or yawn (within three-min) after perceiving a smile/yawn from another toddler. Sex, age, and parents’ country of origin did not influence RSM and YC occurrence, probably because gonadal maturation was long to come, the age range was skewed towards the early developmental phase, and toddlers had been in the same social group for months. RSM and YC showed social modulation, thus possibly implying more than just motor resonance. Both phenomena were inversely related to affiliation levels (a social bond proxy). Because literature reports that in adults RSM and YC may increase with familiarity, our reversed result suggests that in certain toddler cohorts the same phenomena may help increase socio-emotional coordination and that the function of motoric resonance may be experience- and context-dependent. (shrink)