Shemore thanhe: gender bias supports the empathic nature of yawn contagion inHomo sapiens

Abstract

Psychological, clinical and neurobiological findings endorse that empathic abilities are more developed in women than in men. Because there is growing evidence that yawn contagion is an empathy-based phenomenon, we expect that the female bias in the empathic abilities reflects on a gender skew in the responsiveness to others’ yawns. We verified this assumption by applying a linear model on a dataset gathered during a 5 year period of naturalistic observations on humans. Gender, age and social bond were included in the analysis as fixed factors. The social bond and the receiver’s gender remained in the best model. The rates of contagion were significantly lower between acquaintances than between friends and family members, and significantly higher in women than in men. These results not only confirm that yawn contagion is sensitive to social closeness, but also that the phenomenon is affected by the same gender bias affecting empathy. The sex skew, also found in other non-human species, fits with the female social roles which are likely to require higher empathic abilities (e.g. parental care, group cohesion maintenance, social mediation). The fact that female influence in social dynamics also relies on face-to-face emotional exchange raises concerns on the negative repercussions of having women’s facial expressions forcibly concealed.

Are Yawns really Contagious? A Critique and Quantification of Yawn Contagion

“…We acknowledge that yawns appear to vary throughout the day and according to one's chronotype (Zilli et al 2007). Further, we acknowledge that individual differences associated with social awareness or mentalizing also bear upon one's tendency to contagiously yawn (Bartholomew and Cirulli 2014;Demuru and Palagi 2012;Norscia et al 2016;Norscia and Palagi 2011;Palagi et al 2009;Platek et al 2003;Rundle et al 2015). We acknowledge that some existing experimental protocols are used to mitigate the influence of social factors.…”

“…And yet, perception is a necessary but not sufficient explanation: it is known that yawn contagion is primarily a function of social considerations. We are far more likely to yawn to close family and friends, than we are to strangers or acquaintances (Demuru and Palagi 2012;Norscia and Palagi 2011); indeed, empathy, theory of mind, self-awareness, and psychopathy-related traits are all associated with one's tendency to yawn contagiously (Bartholomew and Cirulli 2014;Norscia et al 2016;Palagi et al 2009;Platek et al 2003;Rundle et al 2015). Contagious yawning has been observed in non-humans, and is typically associated with that species' social abilities (Demuru and Palagi 2012;Gallup et al 2015;Madsen et al 2013;Palagi et al 2009;Romero et al 2014).…”

“…For example, as recently as last year, Gallup et al (2016) wrote: BSince the rate of spontaneous yawning is quite infrequent, and studies have demonstrated that participants yawn much more frequently when watching a video stimulus depicting yawns compared to control stimuli, we can be confident that the vast majority of yawns reported in the current experiment were contagious [rather than spontaneous]^(pp. 3), and Norscia et al (2016) that: B…we recorded yawn responses within a 3 min (sic) time window, thus reducing the probability of mistakenly coding spontaneous yawns as yawn responses^(pp. 3; emphasis added).…”

“…Some studies categorize as contagious any yawn that occurs up to 5-min after a trigger yawn (Madsen et al 2013;Palagi et al 2009;Provine 1986), some limit this to 3-min (Demuru and Palagi 2012;Norscia et al 2016;Norscia and Palagi 2011) and some do not report at all the window in which they consider a yawn spontaneous or contagious (Bartholomew and Cirulli 2014;Platek et al 2003). Moreover, some authors exclude yawns that occur in the appropriate window of time if they cannot directly attribute it to a single trigger (thus systematically biasing latency measurements and ignoring base-rates; Demuru and Palagi 2012;Norscia et al 2016;Norscia and Palagi 2011). Independent of this, the difficulty of observing contagious yawns in the wild has led researchers to employ extreme induction methods in the lab.…”

Facial expressions and pair bonds in hylobatids

“…Humans connect emotionally to one another through emotional contagion facilitated by RFM (Zajonc, ) a coupling that is probably also present in other animals (Palagi, Nicotra, & Cordoni, ; Nakahashi & Ohtsuki, ). RFM also relates to fine‐tuning interactions, indicating intention, strengthening social bonds through shared positive emotions (Davila Ross et al, 2008; Palagi et al, ), and may also lead to mimicking each other in synchronous performances (Anderson, Myowa‐Yamakoshi, & Matsuzawa, 2004; Gladstone & Parker, ; Miles, Griffiths, Richardson, & Macrae, ; Norscia, Demuru, & Palagi, ; Provine, ; Romero, Ito, Saito, & Hasegawa, ). Synchronizing behavior, including facial behavior, may function to bind partners more closely and to increase affiliation or be an expression thereof (Haidt, Seder, & Kesebir, ; Hattori, Tomonaga, & Matsuzawa, ; Paukner, Suomi, Visalberghi, & Ferrari, ; Romero et al, ).…”