Comparison of the social triggering model and the cognitive suggestion model of yawning

The hypothesis that individuals would yawn more if subjected to a model of yawning accompanied with a cognitive cue of yawning than to eigher stimulus alone was tested. Subjects from four groups individually observed a 10-min video in which the experimenter modelled either a yawn or a hiccup every thirty seconds while a second experimenter read a passage about the respiratory system describing either yawns or hiccups. Although yawning was scarce, more temptations to yawn occurred if either the visual or cognitive stimuli were presented than if neither of them were. No interactive or additive effect of the two manipulations occurred. In other words, seeing and hearing about yawns was equivalent to seeing yawns with hearing hiccups and seeing hiccups with hearing yawns. Diverse reasons of the purpose of yawning were evaluated.