Abstrakt
Many socially living species are able to perceive chemical cues to the emotional state of their conspecifics The main aim of this paper is to review the current body of evidence about emotion-related odours in humans from the viewpoint of the signalling theory.This approach differentiates between signals and cues, which are assumed to result from different selective pressures. Signals are of adaptive advantage to both the sender and receiver and show a specific design behind such adaptations.On the other hand, traits that were not directly selected for communication purposes but perceivers are nonetheless adapted to be attentive to are called cues.The results of the studies conducted so far indicate that humans are able to distinguish between the odours of other individuals who have been experiencing various affective states to some extent.However, often it is difficult for them to identify the specific affective context in which the odour has been sampled.In other studies it was found that exposure to odour samples collected in a stressful situation changes the perceivers' cognitive functioning and behaviour, even though they may not be aware of what the odour refers to or may not even perceive it on the supraliminal level.
For example, exposure to an odour collected in a stressful situation may increase a startle response, greater tendency to risk-taking behaviour or an increase in the level of anxiety or sensory bias in the perception of another person.These changes are more profound in socially anxious individuals. According to the evidence currently available, perception of emotion-related odours indicate the specific adaptive design in the perceiver's olfactory cognition, which allows us to tentatively conclude that human body odour contains cues to affective states to the others.
In contrast, the evidence regarding proximate mechanisms behind the production of such odours is missing, which makes it impossible to conclude whether these could be termed signals.