Social chemosignals, but not common odors valence, modulate approach/avoidance response tendencies

Actions of basic motivational tendency are differentially influenced by stimulus valence: positive stimuli are approached and negative stimuli are avoided. This affective-motor biasis stronger with social-informative facial expression. In 3 experiments, we determined whether common odors or social chemosignals (body odors from an unknown individual) modulate this basic approach-avoidance bias towards human facial expressions. Within an approach-avoidance task (AAT), participants responded by pulling towards or pushing away a joystick in response to happy, angry, and neutral facial expressions paired with no odor (Study 1, n=10), or neutral, pleasant, and unpleasant common odors (Study 2; n=20), or perceptually masked social chemosignals (Study 3; n=25). In Study 1, we replicated that individuals both approach happy faces and avoid angry faces more quickly. In Study 2, odors – independent of valence – removed the established approach and avoidance effects, which suggests that odors acted as distractors. In Study 3, an initial discrimination test determined that the body odor masked with an odor mixture of neutral valence was perceptually indiscriminable from the mixture itself. Preliminary analyses of the ATT result suggests that only when faces were paired with the masked social chemosignal were participants faster at approaching happy faces and avoiding angry faces. As in Study 2, when paired with the masker alone, the approachavoidance effect was eliminated. These findings indicate that social chemosignals, but not common odors, are able to induce differential behavioral responses to emotional stimuli. Furthermore, these social chemosignal-dependent effects occur outside perceptual awareness. Acknowledgements: Supported by the Knut and Alice Wallenberg foundation (KAW 2012.0141) awarded to JNL. FCOI Disclosure: None