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Olfaction-mediated behavioural defence mechanisms in humans
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Croy, Ilona (referee) ; Polák, Jakub (referee)
This thesis consists of two parts. The first part introduces the importance of behavioural defence mechanisms, specifically the behavioural immune system and mainly in humans. I review current knowledge regarding behavioural defence mediated by odour cues. Although behavioural defence mechanisms are important for all individuals who live in social groups, I focus on mate choice, because that is the context in which olfaction-mediated behavioural defence is studied the most. Subsequently, the importance of olfaction is demonstrated using the example of self-inspection and I discuss how the behavioural immune system may be intertwined with this relatively understudied behaviour. Finally, last chapter deals with associations between olfaction and other modalities that play a role in the detection of cues which help select a healthy and immunocompetent partner. In the second part of the thesis, I present nine papers: three reviews and six empirical studies. The review papers summarise the functioning of the behavioural immune system, olfaction- mediated pathogen avoidance in mammals, and the merely weak association between attractiveness ratings based on different modalities. The first empirical paper investigates whether the threat caused by the Covid-19 pandemic led to increased perceived disgust,...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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Mechanisms of human body odour production
Hrubová, Noemi ; Havlíček, Jan (advisor) ; Stopková, Romana (referee)
The sterile secret of skin glands is not immediately odoriferous. The characteristic body odour is released after microorganism transformation of the secreted compounds. The aim of the work is to elucidate the mechanisms of the body odour production. The major contributor to the body odour are volatile fatty acids hydrolysed from glutamine precursors, structurally unusual long- chain fatty acids or lipids. Another component are sulphur compounds, mainly secreted as the Cys-Gly-(S) conjugates, and steroid substances. The genus Corynebacterium is associated with these transformations and intense body odour. The composition of the resident microflora varies depending on age and gender. Axillary odour with large apocrine secretion has probably biggest importance for human chemical communication. Apocrine glands secretion starts during puberty and decreases in postmenopausal women. There are quantitative differences between gender composition of sweat. In the Asian population is more common the recessive homozygosity of the ABCC11 gene which is associated with lower body odour intensity. Also MHC proteins effect body odour and they seem to play a role in mate choice. To some extent, the environmental factors such as diet or emotions influence body odour. Knowledge of mechanisms behind body odour...
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Mate choice based on olfactory imprinting-like effect
Kuncová, Lucie ; Havlíček, Jan (advisor) ; Špinka, Marek (referee)
Previous studies have shown that women choose partners resembling their fathers in various characteristics. However, none of the studies have focused on woman's father-partner body odour similarity, even though body odour plays an important role in mate choice. The main aim of our study was to test whether the woman's father and partner body odour is similar and whether the rating of this similarity was affected by the body odour's intensity and pleasantness. Further, we wanted to know whether the quality of woman's relationship with her father during her childhood influences the body odour similarity. We also tested the effect of woman's father-partner body odour similarity on sexual and relationship satisfaction. Twenty-five women with their fathers and partners participated in the study. Every respondent completed a set of questionnaires, in addition, fathers and partners provided samples of their body odours. Body odour similarity was rated by independent female raters (N=128). According to the results of our study, body odour of woman's father and partner is significantly similar. The body odour was also similar in intensity and pleasantness. The quality of woman's relationship with her father does not affect woman's father-partner body odour similarity. Nevertheless, this similarity...
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Relationship between reactivity of immune system and quality of human body odour
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
It was previously proposed that expression of secondary sexual characteristics may provide cues to individual's immunocompetence. Body odour could partly serve as one of such characteristics, which provides crucial information about potentional partner even in humans. The main aim of the diploma thesis was to test a relationship between body odour quality and reactivity of immune system. In empirical part of the study we collected body odour samples from 21 men aged between 18-40 years before and two weeks after the vaccination against hepatitis A and B (Twinrix) and meningococcus (Menveo). The participant's blood samples were obtained three times to determine levels of IgG and IgM antibodies (markers of reactivity of immune system), testosterone, cortisol and CRP levels. In the second part of the study, a panel of 88 female raters aged 18-40 assessed body odour samples for their attractiveness, intensity and healthiness. In contrast to our expectations, we found no significant association between levels of antibodies induced by vaccination and perceived body odour attractiveness and health. Simultaneously, there were no significant changes in body odour ratings, neither in levels of testosterone and cortisol ratings, before and after the vaccination. However, we found a negative association...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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Kin recognition in humans
Kapicová, Lucie ; Štěrbová, Zuzana (advisor) ; Frynta, Daniel (referee)
This work reviews various papers focused on human kin recognition. First, it briefly describes evolutionary reasons for kin recognition; then, it deals with issues regarding the terminology, and it continues with the introduction of recognition mechanisms (phenotype matching, recognition alleles, spatial distribution and association) and of modalities utilized for recognition (visual, olfactory, acoustic, and tactile modalities). This work also discusses the cultural aspects of kin recognition. Cultural aspects are often omitted by authors even though they play an important role in human kin recognition. This works links the cultural aspects of kin recognition with the biological ones.
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Choice of perfumes and their interaction with body odour
Gwužďová, Markéta ; Havlíček, Jan (advisor) ; Martinec Nováková, Lenka (referee)
The traditional assumption that perfumes are used only for masking of the body odour was doubted by the results of recent researches. In spite of the fact that the biological role of human body odour is very important, it is likely that perfumes are not in conflict with the body odour but there is mutual cooperation. Individuals could choose the scent which goes with their body odour instead of hiding it. In the theoretical part of this thesis I describe a dual inheritance theory, which is a basic concept for our research. We have been concerned with the interaction between biological effects of body odour and social effects of perfumes. Moreover, we have worked on the assumption that the body odour of relatives is similar. We have tested if people are better in their choice of the appropriate perfume for their relatives than for anyone else, in this case partners. Which perfume fits into which body odour was assessed by the independent evaluators of opposite sex because one of the main objectives of chemical signalling is to attract a potential partner. Surprisingly, the results of our research have shown that in the case of couples, the samples of the body odour and perfumes chosen by female partners were slightly better evaluated than the perfumes chosen by men themselves. Moreover, there were...
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The effect of caloric intake and aromatic substances on the human body odour quality
Fialová, Jitka ; Havlíček, Jan (advisor) ; Martinec Nováková, Lenka (referee)
Previous work has shown that mate choice is in part affected by cues associated with quality and condition of potential mate. These cues could be based on visual characteristics or as shown recently on chemical cues. There is growing evidence which suggest that body odour plays relatively significant role in mate choice. Moreover, body odour is to some extent affected by ingested diet. Therefore, we focused on the effect of caloric restriction and garlic consumption on axilary odour. Our results suggest that restoration of food intake improve body odour in terms of pleasantness and attractiveness (probably as a consequence of recommended specific diet), but during caloric restriction it is rated lower. The garlic consumption improves hedonic assessment of body odour. This effect could be ascribed to his well-known health effects. Our findings thus confirm assumption that ingested diet affects body odour and these changes in odour attractiveness could serve as a cue to individual condition and quality.
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