Volume 11, Number 9
Communication among human beings commonly occurs through the sensory modalities of hearing, vision, and touch. Although we typically don’t think about communication via the olfactory sense, we do pay attention to smell though personal hygiene practices such as cleanliness and the use of deodorant. But are odors part of human communication at a nonconscious level?
It has been established that the chemical makeup of sweat from the apocrine sweat glands (e.g., armpits) varies based upon an individual’s emotional state. Furthermore, it has been determined that fear appears to be communicated via sweat odor. Can positive emotional states also be communicated via such emotional “chemosignaling?”
Investigators from The Netherlands, United Kingdom, and Portugal collaborated to study this question and published their results in a recent article in Psychological Science. Sweat samples were obtained from a group of research participants after different emotional states were induced by having them watch happy, frightening, or neutral film clips. Subsequently, a different set of research participants were exposed to these sweat samples, and a number of responses were measured in these recipients. The responses included facial muscle activity to ascertain the extent to which there were reactions in the muscles involved with smiling or fear expression, and several cognitive tasks to determine how attention was affected by the sweat samples. Attention is known to be broader in positive mood states and narrower in negative mood states. Beyond what would be expected by chance, “happy” sweat indeed induced positive affect in the receivers (i.e., muscle activity consistent with smiling, and a more global attentional state), whereas “fear” sweat evoked responses consistent with fear. Recipients were not aware that these subtle changes were occurring.
It is known that emotions are contagious, and this research suggests that the sense of smell appears to play a role in emotional contagion. Are there health implications of chemosignaling? Persons who experience a preponderance of positive emotional states (positive affectivity) tend to have better health than persons who experience a preponderance of negative emotional states (negative affectivity). Chemosignaling, therefore, may be one pathway by which being in social environments replete with positive emotions has health-enhancing benefits.by