You're in a loud and sweaty Italian dance club when a woman approaches you. To be heard over the techno, she leans in close and yells into your ear, "Hai una sigaretta?"

If she spoke into your right ear, you would be twice as likely to give her a cigarette than if she asked by your left ear, according to a new study that employed this methodology in the clubs of Pescara, Italy. Of 88 clubbers who were approached on the right, 34 let the researcher bum a smoke, compared with 17 of 88 whom she approached on the left.

"The present work is one of the few studies demonstrating the natural expression of hemispheric asymmetries, showing their effect in everyday human behavior," write psychologists Daniele Marzoli and Luca Tommasi of the University G. d’Annunzio in Italy in the journal Naturwissenschaften.

It's the latest in a series of studies that show that sound from both human ears is processed differently within the brain. Researchers have noted that humans tend to have a preference for listening to verbal input with their right ears and that given stimulus in both ears, they'll privilege the syllables that went into the right ear. Brain scientists hypothesize that the right ear auditory stream receives precedence in the left hemisphere of the brain, where the bulk of linguistic processing is carried out.

What's surprising about the study is that ear choice had such a decided impact on the behavior of participants in a natural, or as the researchers put it, ecological, setting. Why would people feel more generous when their right ears are addressed?

Marzoli and Tommasi write that some work has shown that the left and right hemispheres of the brain appear to be tuned for positive and negative emotions, respectively. Talk into the right ear and you send your words into a slightly more amenable part of the brain.

"These results seem to be consistent with the hypothesized differential specialization of right and left hemispheres," they write.

In addition to the direct cigarette-ask study, they also simply observed people interacting and also asked for cigarettes without directing their requests towards a particular ear. The Italian researchers picked the night club setting because the loud music allowed the cigarette-asker to approach people and speak directly into one ear without seeming "odd."

While the liquored-up setting might seem unconventional, they view their work in a real life setting as a valuable counterbalance to highly artificial in-lab psychological studies.

"[W]e would finally like to add that it is of utmost importance, in times of massive use of imaging techniques (that by definition impose severe constraints on the observation of neural activities in freely acting subjects) to continue to provide ecological evidence of brain functioning," they conclude.

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Image: flickr/THEfunkyman

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