Body odors (even when masked) make you more emotional: behavioral and neural insights

Cinzia Cecchetto,Domenica Bueti,Raffaella Ida Rumiati,Elisa Lancini,Valentina Parma

doi:10.1038/s41598-019-41937-0

Abstract

Morality evolved within specific social contexts that are argued to shape moral choices. In turn, moral choices are hypothesized to be affected by body odors as they powerfully convey socially-relevant information. We thus investigated the neural underpinnings of the possible body odors effect on the participants’ decisions. In an fMRI study we presented to healthy individuals 64 moral dilemmas divided in incongruent (real) and congruent (fake) moral dilemmas, using different types of harm (intentional: instrumental dilemmas, or inadvertent: accidental dilemmas). Participants were required to choose deontological or utilitarian actions under the exposure to a neutral fragrance (masker) or body odors concealed by the same masker (masked body odor). Smelling the masked body odor while processing incongruent (not congruent) dilemmas activates the supramarginal gyrus, consistent with an increase in prosocial attitude. When processing accidental (not instrumental) dilemmas, smelling the masked body odor activates the angular gyrus, an area associated with the processing of people’s presence, supporting the hypothesis that body odors enhance the saliency of the social context in moral scenarios. These results suggest that masked body odors can influence moral choices by increasing the emotional experience during the decision process, and further explain how sensory unconscious biases affect human behavior.

Highlights

Morality evolved within specific social contexts that are argued to shape moral choices
We first tested whether the masking procedure applied to cover the masked body odor had the expected perceptual impact and rendered the olfactory conditions equivalent in their basic perceptual dimensions
As human body odors are powerful messengers for socially-relevant information[63], able to modulate the behavior and neural processing of the receiver[13,14,23,39,53,54,55], we hypothesized that body odors might affect moral choices through the modulation of the perceived social context

Summary

Introduction

Morality evolved within specific social contexts that are argued to shape moral choices. When processing accidental (not instrumental) dilemmas, smelling the masked body odor activates the angular gyrus, an area associated with the processing of people’s presence, supporting the hypothesis that body odors enhance the saliency of the social context in moral scenarios These results suggest that masked body odors can influence moral choices by increasing the emotional experience during the decision process, and further explain how sensory unconscious biases affect human behavior. Unconscious biases can influence moral decisions based on a variety of stimuli such as attitudes (such as dispositions towards people or places)[11], implicit stereotypes (such as judging a person as attractive or unintelligent because is a cheerleader)[11] or somatic reactions (such as endocrine release or psychophysical reactions)[12] This line of research has not yet considered the possibility of evaluating the effects of social information transmitted via sensory subliminal cues, such as odors. Odors are able to transfer social information and their effect on moral choices seems to modulate harm avoidance

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