Are humans constantly but subconsciously smelling themselves?

Olfactory self-inspection: Own body odour provides cues to one's health and hygiene status

Olfactory self-inspection has been observed in various mammals, including humans. This behaviour can help individuals to monitor own state, including health and hygiene. This study's aim was to explore the frequency of sniffing particular body parts and investigate possible gender differences. Further, we tested a possible function of this behaviour, namely monitoring health and hygiene, by investigating associations between the frequency of self-sniffing and health, hygiene, and disgust sensitivity. Respondents completed an online survey on self-sniffing behaviour, health status, hygiene habits, and disgust sensitivity. Self-sniffing behaviour was investigated using a purpose-built inventory which explored the incidence and frequency of sniffing different parts of own body. Principal Component Analysis identified three main axes of self-sniffing behaviour: Social acceptability self-inspection, Intimate self-inspection, and Cosmetic self-inspection. Our results further show that respondents with lower standards of hygienic habits engage significantly more in intimate self-inspection (sniffing body parts such as genitals, anus, or navel). Interestingly, individuals who reported more frequent health issues sniff more frequently areas such as the armpits, feet, or own breath (Social acceptability self-inspection), probably to check for possible changes in smell due to illness. Our results indicate that olfactory self-inspection probably has several functions depending on the location from which the smell originates.

Body odor disgust sensitivity (BODS) is related to extreme odor valence perception

Odors are important disease cues, and disgust sensitivity to body odors reflects individual differences in disease avoidance. The body odor disgust sensitivity (BODS) scale provides a rapid and valid assessment of individual differences. Nevertheless, little is known about how individual differences in BODS might correlate with overall odor perception or how it is related to other differences in emotional reactivity (e.g., affect intensity). We investigated how BODS relates to perceptual ratings of pleasant and unpleasant odors. We aggregated data from 4 experiments (total N = 190) that were conducted in our laboratory, and where valence and intensity ratings were collected. Unpleasant odors were body-like (e.g., sweat-like valeric acid), which may provide disease cues. The pleasant odors were, in contrast, often found in soap and cleaning products (e.g., lilac, lemon). Across experiments, we show that individuals with higher BODS levels perceived smells as more highly valenced overall: unpleasant smells were rated as more unpleasant, and pleasant smells were rated as more pleasant. These results suggest that body odor disgust sensitivity is associated with a broader pattern of affect intensity which causes stronger emotional responses to both negative and positive odors. In contrast, BODS levels were not associated with odor intensity perception. Furthermore, disgust sensitivity to odors coming from external sources (e.g., someone else's sweat) was the best predictor of odor valence ratings. The effects were modest in size. The results validate the BODS scale as it is explicitly associated with experimental ratings of odor valence.

Different armpits under my new nose: Olfactory sex but not gender affects implicit measures of embodiment

Conflicting multisensory signals may alter embodiment to produce self-identification with a foreign body, but the role of olfaction in this process has been overlooked. We studied in healthy participants how sex (male and female sweat odors) and gender (male and female cosmetic scents) olfactory stimuli contribute to embodiment. Participants saw, on a head mounted display, the first-person perspective of a sex mismatching person. Synchronous visuotactile stimulation was applied to enhance illusory embodiment. Simultaneously, they smelled either sex- or gender- congruent or incongruent stimuli. We assessed implicit (skin conductance responses to visual threats) and explicit (questionnaire) measures of embodiment. Stronger responses to threat were found when participants smelled the sex-congruent compared to the sex-incongruent odor, while no such differences were found for the cosmetic scents. According to the questionnaire, embodiment did not differ between conditions. Post-experimental assessment of the presented cues, suggest that while both sweat odors were considered generally male, cosmetic scents were not. The presented scents were generally not associated with the embodied body. Our results suggest that sex-related body odors influence implicit but not explicit aspects of embodiment and are in line with unique characteristics of olfaction in other aspects of cognition.

Sniffing of Body Odors and Individual Significance of Olfaction Are Associated with Sexual Desire: A Cross-Cultural Study in China, India, and the USA

Olfactory sensations contribute to sexual desire and sexual behavior. However, the degree to which individual importance of olfactory function and body odors relate to sexual desire is not known. This study was conducted to preliminarily examine these relationships among Chinese college students (N = 1903) via the Importance of Olfaction Questionnaire, the Body Odor Sniffing Questionnaire, and the Sexual Desire Inventory, which were used to measure subjective significance of olfaction, frequency of sniffing self or others, and sexual desire, respectively. Individuals who assigned higher importance to olfaction or engaged more in body odor sniffing showed stronger sexual desire. We further explored these associations in different cultures to determine whether cultural consistency existed. We conducted a second study to make cross-cultural comparisons between Indian (N = 313) and US (N = 249) populations. For both countries, a higher importance placed on olfaction and a higher prevalence of body odor sniffing were consistently associated with stronger sexual desire. In conclusion, our study confirmed that people who placed more value on olfactory function or engaged more in body odor sniffing showed stronger sexual desire. These correlations were consistent for both sexes and across different cultures, further indicating the importance of olfaction in sexuality.

Do you often sniff yourself or others? Development of the Body Odor Sniffing Questionnaire and a cross-cultural survey in China and the USA

OBJECTIVES

Body odor can convey much information about an individual and thus we frequently engage in sniffing one's own and other people's body odor. However, there is scarce evidence on the within- and cross-cultural variation in body odor sniffing behaviors and no psychometric scale for specifically measuring such behaviors. Hence, our study aimed to develop the Body Odor Sniffing Questionnaire (BOSQ) and used it to make a cross-cultural comparison.

METHODS

In Study 1, 2,026 participants were recruited from our university, with one half used for exploratory factor analysis (EFA) to examine the factor structure of the BOSQ (sample 1) and the other half used for confirmatory factor analysis (CFA) to verify the factor structure (sample 2). In Study 2, 352 Chinese and 254 US participants were recruited to complete the BOSQ through Wenjuanxing and Amazon Mechanical Turk, enabling comparison of body odor sniffing behaviors across two cultures.

RESULTS

The Study 1 results showed that the BOSQ comprises 17 items in three factors: self-private body odor, others' body odor, and self-common body odor. The CFA results further supported that this three-factor model was a good fit. The Study 2 results showed that US participants scored higher overall and on the self-private body odor and others' body odor dimensions, whereas Chinese participants scored higher on the self-common body odor dimension.

CONCLUSIONS

The BOSQ demonstrated good reliability and validity, which is a useful tool for evaluating individuals' body odor sniffing behaviors. Cross-cultural difference existed as the US population reported a higher prevalence of body odor sniffing behavior, compared to the Chinese population.

There is chemistry in social chemistry

Nonhuman terrestrial mammals sniff themselves and each other to decide who is friend or foe. Humans also sniff themselves and each other, but the function of this is unknown. Because humans seek friends who are similar to themselves, we hypothesized that humans may smell themselves and others to subconsciously estimate body odor similarity, which, in turn, may promote friendship. To test this, we recruited nonromantic same-sex friend dyads and harvested their body odor. We found that objective ratings obtained with an electronic nose, and subjective ratings obtained from independent human smellers converged to suggest that friends smell more similar to each other than random dyads. Last, we recruited complete strangers, smelled them with an electronic nose, and engaged them in nonverbal same-sex dyadic interactions. We observed that dyads who smelled more similar had more positive dyadic interactions. In other words, we could predict social bonding with an electronic nose. We conclude that there is indeed chemistry in social chemistry.

Human odor exploration behavior is influenced by olfactory function and interest in the sense of smell

Olfaction plays an important role in social interaction. This study examined the influence of chemosensory and cognitive abilities on conscious odor sniffing behaviors in humans. Participants (N = 349) were surveyed using a questionnaire for the frequency of behaviors in terms of odor exploration from intrinsic and external sources. Chemosensory functions (e.g., odor identification, trigeminal sensitivity, taste functions, and nasal patency), self-reported olfactory function, and the subjective importance of olfaction were assessed. Hierarchical regression analyses demonstrate a strong impact of olfactory importance on odor exploration behavior. Both female gender and chemosensory function (odor identification ability and trigeminal sensitivity) had a positive impact on odor exploration behavior from individuals' own body and from external sources. Moreover, participants with dysosmia compared to those with normosmia showed less frequent odor exploration behaviors, while their behaviors were partly predicted by nasal patency. In conclusion, conscious olfactory exploration behaviors reflect the interest in the sense of smell and is strongly modulated by chemosensory function. In turn, individuals with lower olfactory sensitivity invest less in olfactory explorations.

COVID-19 and mandatory teleworking from home in Japan: taking stock to improve satisfaction and job performance

Purpose

This exploratory paper aims to examine attitudes and practices with regard to the COVID-19 pandemic, as well as the effects of mandatory teleworking from home in the wake of the first state of emergency orders in Japan in 2020.

Design/methodology/approach

An online survey of married employees retrospectively assessed changes in work style, subjective well-being, work–family conflict and job performance before and during forced teleworking from home in Tokyo and three of the surrounding prefectures.

Findings

Regular employees reported high levels of anxiety and to have thoroughly implemented government-recommended hygiene and safety practices. A majority of respondents were satisfied with mandatory telework from home and desired to continue partial telework after the end of the pandemic. The strongest predictor of satisfaction with mandatory telework from home turned out to be adequate workspace at home for both men and women. However, the antecedents of the desire to continue working from home differed by gender.

Practical implications

These findings can help individuals, firms and governments better understand the effects of mandatory teleworking from home and devise countermeasures to maximize employee well-being and job performance. This is all the more crucial, as Japan has had successive waves of the virus and has declared numerous states of emergency since the beginning of the pandemic, forcing office workers to continue social distancing and remote working for the time being.

Originality/value

To the best of the authors’ knowledge, this research is one of the first to provide insights on how imposed teleworking from home in the context of COVID-19 in Japan affected regular employees’ personal and professional lives and to identify predictors of satisfaction with teleworking and the desire to continue doing so.

The social odor scale: Development and initial validation of a new scale for the assessment of social odor awareness

The degree of attention individuals pay to olfactory cues (called odor awareness) influences the role of odors in everyday life. Particularly, odors produced by the human body (i.e., social odors) are able to carry a wide variety of information and to elicit a broad spectrum of emotional reactions, making them essential in interpersonal relationships. Hence, despite the assessment of awareness toward social odors is crucial, a proper tool is still lacking. Here, we designed and initially validated the Social Odor Scale (SOS), a 12-item scale designed to measure the individual differences in awareness towards different social odors. In Study 1, an exploratory factor analysis (EFA; KMO test: MSA = 0.78; Bartlett's test: χ2(78) = 631.34, p < 0.001; Chi-squared test: χ2(42) = 71.84, p = 0.003) suggests that the three factors structure was the model that best fit with the Italian version of the scale. The confirmatory factor analysis (CFA) supports a second-order model with one higher-order factor representing social odor awareness in general and three lower-order factors representing familiar, romantic partner, and stranger social odors. The final version of the scale presented a good fit (RMSEA = 0.012, SRMR = 0.069, CFI = 0.998, TLI = 0.997). In Study 2, CFA was performed in the German version of the scale confirming the validity of scale structure. Study 3 and 4 revealed that SOS total score and its subscales were positively correlated with other validated olfactory scales, but not with olfactory abilities. Moreover, SOS was found to be related to the gender of the participants: women reported to be more aware to social odors and, specifically, to familiar social odors than men. Overall, the results indicated that SOS is a valid and reliable instrument to assess awareness toward social odors in everyday life.

The self-regulation of face touching - a preregistered experiment testing if-then plans as a means to promote COVID-19 prevention

Objective: Reducing face touching could help slow COVID-19's spread. We tested whether implementation intentions, a simple-to-use behaviour change intervention, reduce face-touching behaviour effectively.Design: In this pre-registered online study, we utilised a novel way to collect behavioural data during a pandemic. We obtained video recordings of 156 adults while performing three engaging tasks for four minutes each. After the baseline task, participants formed the goal to avoid touching their faces; some participants also formed implementation intentions, targeting either the frequency or duration of face touching.Main Outcome Measures: The 468 videos were rated by two independent raters for face touching frequency and duration.Results: Face touching was widespread. Compared to the baseline, there was a slight reduction in the frequency of face touching after the experimental manipulations. We observed a significant decrease in the length of face touching only for participants with duration-focused implementation intentions.Conclusion: While implementation intentions have effectively downregulated other unwanted behaviours, they did not reduce the frequency of face-touching behaviour. Still, duration-focused implementation intentions appear to be a promising strategy for face-touching behaviour change. This highlights the need for further optimisation and field research to test the effectiveness of implementation intentions in everyday life contexts.

Face-touching behaviour as a possible correlate of mask-wearing: A video observational study of public place incidents during the COVID-19 pandemic

Most countries in the world have recommended or mandated face masks in some or all public places during the COVID-19 pandemic. However, mask use has been thought to increase people's face-touching frequency and thus risk of self-inoculation. Across two studies, we video-observed the face-touching behaviour of members of the public in Amsterdam and Rotterdam (the Netherlands) during the first wave of the pandemic. Study 1 (n = 383) yielded evidence in favour of the absence of an association between mask-wearing and face-touching (defined as touches of face or mask), and Study 2 (n = 421) replicated this result. Secondary outcome analysis of the two studies-analysed separately and with pooled data sets-evidenced a negative association between mask-wearing and hand contact with the face and its t-zone (i.e. eyes, nose and mouth). In sum, the current findings alleviate the concern that mask-wearing has an adverse face-touching effect.

Limitations in odour simulation may originate from differential sensory embodiment

Across diverse lineages, animals communicate using chemosignals, but only humans communicate about chemical signals. Many studies have observed that compared with other sensory modalities, communication about smells is relatively rare and not always reliable. Recent cross-cultural studies, on the other hand, suggest some communities are more olfactorily oriented than previously supposed. Nevertheless, across the globe a general trend emerges where olfactory communication is relatively hard. We suggest here that this is in part because olfactory representations are different in kind: they have a low degree of embodiment, and are not easily expressed as primitives, thereby limiting the mental manipulations that can be performed with them. New exploratory data from Dutch children (9-12 year-olds) and adults support that mental imagery from olfaction is weak in comparison with vision and audition, and critically this is not affected by language development. Specifically, while visual and auditory imagery becomes more vivid with age, olfactory imagery shows no such development. This is consistent with the idea that olfactory representations are different in kind from representations from the other senses. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.

Human olfactory communication: current challenges and future prospects

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'.

Interdisciplinary challenges for elucidating human olfactory attractiveness

Many species use chemicals to communicate. In humans, there is increasing evidence that chemicals conveyed by the body are extremely important in interpersonal relationships. However, many aspects of chemical communication remain to be explored to fully understand this function in humans. The aim of this article is to identify relevant challenges in this field, with a focus on human attractiveness in the context of reproduction, and to put forward roadmaps for future studies that will hopefully extend to a wider range of social interactions. The first challenge consists in not being limited to body (mal)odours from the axilla. Preliminary data on how the odour of the face and head is perceived are presented. Second, there is a crucial need to increase our knowledge of the chemical bases of human chemical communication. Third, cross-cultural approaches must not be overlooked, because they have a major input in understanding the universal and culture-specific aspects of chemical communication. Fourth, the influence of specific cultural practices such as contraceptive and fragrance use is likely to be prominent and, therefore, needs to be well described. The fifth and last challenge for research projects in this field is the integration of different disciplines such as behavioural sciences, social sciences, neurosciences and microbiology. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.