Chemosensory signals of competition increase the skin conductance response in humans

In vertebrates, chemosensory signals of competition are communicated between conspecifics, eliciting behavioral and physiological adaptations in the perceiving animal. The current study investigates, whether chemosensory signals of competition are also communicated between humans, and whether they elicit physiological changes in the perceiver. It is further investigated whether personality traits alter this physiological responding. Axillary sweat was collected from six male donors during a competition (badminton match) and a sport control condition (running). The donors' testosterone rose stronger during the competition as compared to the sport control condition. The chemosensory stimuli were presented to 18 (9 male) participants through a constant-flow olfactometer, while the skin conductance response (SCR) was measured. Results reveal that the SCR was larger in response to chemosensory signals collected during the competition condition as compared to those collected during the sport control condition. Furthermore, regression analyses showed, that higher scores on trait social anxiety were related to larger SCRs towards the chemosensory signals of competition. The current result suggests that chemosensory signals of competition can be communicated between humans, and that they elicit orienting in the perceiving individual. These data are consistent with current research, suggesting that high socially anxious individuals process threatening social information preferentially. The current results add to the growing body of research into human chemosensory communication of social information, and extend previous research on the chemosensory communication of anxiety.

Research Highlights
► Competitive emotions can be transmitted chemosensorily between humans.
► Chemosensory perception of competition increases autonomic arousal in humans.
► Socially anxious individuals process threatening chemosignals preferentially.