Hemispheric asymmetries and side biases have been studied in humans mostly in laboratory settings, and evidence obtained in
naturalistic settings is scarce. We here report the results of three studies on human ear preference observed during social
interactions in noisy environments, i.e., discotheques. In the first study, a spontaneous right-ear preference was observed
during linguistic exchange between interacting individuals. This lateral bias was confirmed in a quasi-experimental study
in which a confederate experimenter evoked an ear-orienting response in bystanders, under the pretext of approaching them
with a whispered request. In the last study, subjects showed a greater proneness to meet an experimenter’s request when it
was directly addressed to the right rather than the left ear. Our findings are in agreement both with laboratory studies on
hemispheric lateralization for language and approach/avoidance behavior in humans and with animal research. The present work
is one of the few studies demonstrating the natural expression of hemispheric asymmetries, showing their effect in everyday
human behavior.
Keywords Side bias - Ear preference - Behavioral lateralization - Communication - Hemispheric asymmetries - Approach/avoidance behavior - Homo sapiens