Human olfactory communication: current challenges and future prospects

Abstract

Although anthropologists frequently report the centrality of odours in the daily lives and cultural beliefs of many small-scale communities, Western scholars have historically considered the sense of smell as minimally involved in human communication. Here, we suggest that the origin and persistence of this latter view might be a consequence of the fact that most research is conducted on participants from Western societies who, collectively, were rather old (adults), deodorized and desensitized (ODD) to various aspects of olfactory perception. The view is rapidly changing, however, and this themed issue provides a timely overview of the current state-of-the-art on human chemocommunication. Based on evolutionary models of communication, the papers cover both general mechanisms of odour production by ‘senders’ and odour perception by ‘receivers’. Focus on specific functional contexts includes reciprocal impact of odours between infants and mothers, the role of odour in mate choice and how odours communicate emotion and disease. Finally, a position paper outlines pitfalls and opportunities for the future, against the context of the replication crisis in psychology. We believe a more nuanced view of human chemical communication is within our grasp if we can continue to develop inter-disciplinary insights and expand research activities beyond ODD people. This article is part of the Theo Murphy meeting issue ‘Olfactory communication in humans’.

More Data, Please: Machine Learning to Advance the Multidisciplinary Science of Human Sociochemistry

“…Although initially useful, this gender uniformity adds a constraint on generality, and the same goes for the almost exclusive reliance on participants that are Western, Educated, Industrialized, Rich, Democratic (WEIRD; Henrich et al, 2010) (cf. de Groot et al, 2018;Roberts et al, 2020). Generalizing research findings from WEIRD samples to other populations is a major problem in science in general, and a particularly pressing issue when one examines the breadth and scale of the non-verbal language of smells (Box 2).…”

“…In our everyday lives, smells have a "communicative" function, informing us about the quality of food and warning us for environmental hazards (e.g., gas leaks) (Stevenson, 2010). An even less well-known function of smell is social communication (de Groot et al, 2017;Parma et al, 2017;Pause, 2017;Roberts et al, 2020); the topic of this article. Studies have shown that our smells provide others with cues about our identity and gender (Penn et al, 2007), age (Mitro et al, 2012), health (Olsson et al, 2014), and emotions (de Groot et al, 2015;Pause et al, 2020).…”

“…Social smells are markedly complex: body odor contains thousands of molecules (de Lacy Costello et al, 2014), and massive variability is caused by factors including genotype, hormonal status, mood, skin bacteria, diet, smoking, hygiene habits, clothing, and use of fragranced products (e.g., Natsch and Emter, 2020;Roberts et al, 2020). Past studies have generally sidestepped this challenge by performing small-scale psychological experiments under carefully controlled, sterile conditions (for a meta-analysis: de Groot and Smeets, 2017; for a critical view: Wyatt, 2020).…”

What Your Nose Knows: Affective, Cognitive, and Behavioral Responses to the Scent of Another Person

“…To answer all these questions will involve a substantial collective research effort, requiring attention from researchers with diverse areas of expertise who, ideally, will collect data from diverse segments of the human population (Roberts, Havlícˇek, & Schaal, 2020). This kind of research is rarely cheap or easy, which can pose a practical barrier to researchers with limited resources (and, even when resources are available, may be a disincentive within a scientific community that prizes large sample sizes).…”

The Role of Knockout Olfactory Receptor Genes in Odor Discrimination

“…This ability is present in micro-organisms as well as in complex species such as mammals. However, during evolution, human beings’ increasing reliance of other senses, such as vision, has decreased our sense of smell [ 2 ]. Nevertheless, the OS is the designated machinery for recognizing and elaborating conscious olfactory stimuli allowing humans to discriminate more than a trillion odorant stimuli [ 3 , 4 ].…”