Citation

de Groot JH, Smeets MA, Semin GR. PLoS One 2015; 10(2): e0118211.

Affiliation

Department of Social and Organizational Psychology, Faculty of Social and Behavioral Sciences, Utrecht University, Utrecht, the Netherlands; Department of Psychology, Koç University, Istanbul, Turkey; Instituto Superior de Psicologia Aplicada (ISPA), Instituto Universitário, Lisbon, Portugal.

Copyright

(Copyright © 2015, Public Library of Science)

DOI

10.1371/journal.pone.0118211

PMID

25723720

Abstract

Humans can register another person's fear not only with their eyes and ears, but also with their nose. Previous research has demonstrated that exposure to body odors from fearful individuals elicited implicit fear in others. The odor of fearful individuals appears to have a distinctive signature that can be produced relatively rapidly, driven by a physiological mechanism that has remained unexplored in earlier research. The apocrine sweat glands in the armpit that are responsible for chemosignal production contain receptors for adrenalin. We therefore expected that the release of adrenalin through activation of the rapid stress response system (i.e., the sympathetic-adrenal medullary system) is what drives the release of fear sweat, as opposed to activation of the slower stress response system (i.e., hypothalamus-pituitary-adrenal axis). To test this assumption, sweat was sampled while eight participants prepared for a speech. Participants had higher heart rates and produced more armpit sweat in the fast stress condition, compared to baseline and the slow stress condition. Importantly, exposure to sweat from participants in the fast stress condition induced in receivers (N = 31) a simulacrum of the state of the sender, evidenced by the emergence of a fearful facial expression (facial electromyography) and vigilant behavior (i.e., faster classification of emotional facial expressions).

Language: en