Snakes Represent Emotionally Salient Stimuli That May Evoke Both Fear and Disgust

Eye-tracking analysis of attentional disengagement in phobic and non-phobic individuals

This study investigated threat-related attention biases using a new visual search paradigm with eye tracking, which allows for measuring attentional disengagement in isolation. This is crucial as previous studies have been unable to distinguish between engagement, disengagement, and behavioral freezing. Thirty-three participants (Mage = 28.75 years, SD = 8.98; 21 women) with self-reported specific phobia (spiders, snakes, and pointed objects) and their matched controls (Mage = 28.38 years, SD = 8.66; 21 women) took part in the experiment. The participants were instructed to initially focus on a picture in the center of the screen, then search for a target picture in an outer circle consisting of six images, and respond via a button press whether the object in the target picture was oriented to the left or right. We found that phobic individuals show delayed disengagement and slower decision times compared with non-phobic individuals, regardless of whether the stimulus was threat-related or neutral. These results indicate that phobic individuals tend to exhibit poorer attentional control mechanisms and problems inhibiting irrelevant information. We also confirmed a threat-unrelated shared feature effect with complex stimuli (delayed disengagement when an attended stimulus and an unattended target share common stimulus features). This process might play a role in various experimental setups investigating attentional disengagement that has not yet been considered. These findings are important, as good attentional control may serve as a protective mechanism against anxiety disorders.

Interactions between reptiles and people: a perspective from wildlife rehabilitation records

As urbanization expands globally, human-wildlife interactions will inevitably increase. Here, we analysed 10 years of wildlife rehabilitation records of squamate (snake and lizard) reptiles (n = 37 075) from the Greater Sydney region, New South Wales, Australia, to explore their value to address management and conservation issues. Rescues were highly non-random regarding taxonomic focus, spatial occurrences and temporal trends due to the combined influence of (i) reptile phenology and behaviour and (ii) human perceptions of reptiles. Seasonal peaks in rescues reflect reptile and, to a lesser extent, human activity. Spatial patterns of rescues were informative about distributions and presence of easily identified taxa but were primarily driven by human presence. Larger squamate species were rescued more frequently, potentially reflecting a perception of greater danger or rescue priority. While uncommon species were often misidentified, accurate reports of these taxa may guide targeted surveys. The value of these data for conservation and management could be enhanced by emphasizing reptile identification training of volunteers and use of applications for informed species identification. Wildlife rehabilitation data offer a cost-effective means of quantifying thousands of human-reptile interactions, identifying foci (in both time and space) of human-wildlife conflict such as snakebite risk and roadkill-related reptile mortality.

Trends in Reptile Holdings Across UK Zoos: Identification of the Factors Responsible for Declining Numbers of Venomous Snake

Zoos are under increasing pressure to strategically manage their collections to maximize visitor attendance, financial income, and their contribution to conservation. As a result, the compositions of zoo collections are undergoing significant changes. Many zoos are keeping fewer species and prioritizing keeping large flagship animals that are more attractive to the public. To understand the effects these changes are having on captive reptile numbers, we have analyzed the trends in reptile holdings between 2003 and 2023 at UK zoos. Our findings show that despite an overall increase in reptile numbers in the period analyzed, there has been a dramatic decline in the number of venomous snakes held at UK zoos, and as a result, venomous snakes are being excluded from many of the conservation benefits that zoos provide. To understand the key factors contributing to the decline in venomous snake numbers, 57 staff members across 35 different BIAZA-accredited zoos were surveyed. Results from the survey identified that a perceived increased risk of harm, increasingly stringent health and safety regulations, and increased husbandry requirements were all key contributing factors to why venomous snake numbers at zoos are in decline.

Effects of relational and instrumental messaging on human perception of rattlesnakes

We tested the effects of relational and instrumental message strategies on US residents' perception of rattlesnakes-animals that tend to generate feelings of fear, disgust, or hatred but are nevertheless key members of healthy ecosystems. We deployed an online survey to social media users (n = 1,182) to describe perceptions of rattlesnakes and assess the change after viewing a randomly selected relational or instrumental video message. An 8-item, pre-and post-Rattlesnake Perception Test (RPT) evaluated perception variables along emotional, knowledge, and behavioral gradients on a 5-point Likert scale; the eight responses were combined to produce an Aggregate Rattlesnake Perception (ARP) score for each participant. We found that people from Abrahamic religions (i.e., Christianity, Judaism, Islam) and those identifying as female were associated with low initial perceptions of rattlesnakes, whereas agnostics and individuals residing in the Midwest region and in rural residential areas had relatively favorable perceptions. Overall, both videos produced positive changes in rattlesnake perception, although the instrumental video message led to a greater increase in ARP than the relational message. The relational message was associated with significant increases in ARP only among females, agnostics, Baby Boomers (age 57-75), and Generation-Z (age 18-25 to exclude minors). The instrumental video message was associated with significant increases in ARP, and this result varied by religious group. ARP changed less in those reporting prior experience with a venomous snake bite (to them, a friend, or a pet) than in those with no such experience. Our data suggest that relational and instrumental message strategies can improve people's perceptions of unpopular and potentially dangerous wildlife, but their effectiveness may vary by gender, age, religious beliefs, and experience. These results can be used to hone and personalize communication strategies to improve perceptions of unpopular wildlife species.

No evidence of attentional prioritization for threatening targets in visual search

Throughout human evolutionary history, snakes have been associated with danger and threat. Research has shown that snakes are prioritized by our attentional system, despite many of us rarely encountering them in our daily lives. We conducted two high-powered, pre-registered experiments (total N = 224) manipulating target prevalence to understand this heightened prioritization of threatening targets. Target prevalence refers to the proportion of trials wherein a target is presented; reductions in prevalence consistently reduce the likelihood that targets will be found. We reasoned that snake targets in visual search should experience weaker effects of low target prevalence compared to non-threatening targets (rabbits) because they should be prioritized by searchers despite appearing rarely. In both experiments, we found evidence of classic prevalence effects but (contrasting prior work) we also found that search for threatening targets was slower and less accurate than for nonthreatening targets. This surprising result is possibly due to methodological issues common in prior studies, including comparatively smaller sample sizes, fewer trials, and a tendency to exclusively examine conditions of relatively high prevalence. Our findings call into question accounts of threat prioritization and suggest that prior attention findings may be constrained to a narrow range of circumstances.

Human emotional evaluation of ancestral and modern threats: fear, disgust, and anger

Introduction

Animal and human ancestors developed complex physiological and behavioral response systems to cope with two types of threats: immediate physical harm from predators or conspecifics, triggering fear, and the risk of infections from parasites and pathogens leading to the evolution of the behavioral immune system with disgust as the key emotion. Integration of the evolutionary concepts of the fear module and behavioral immune systems has been infrequent, despite the significant survival advantages of disgust in various contexts. Studies comparing attention to ancestral and modern threats accompanied by fear have yielded ambiguous results and what qualifies as salient modern disgusting stimuli remains unclear. We do not know whether disgust or the behavioral immune system, as inherent aspects of human psychology, have adapted to safeguard us from pandemic risks or poisoning by modern toxic substances.

Methods

To test these effects, we have developed a survey comprised of 60 short vignettes describing threats evoking fear and disgust belonging to one of the three main categories of threats: (1) ancestral (phylogenetic), (2) modern (ontogenetic), and (3) pandemics of airborne disease. Each vignette was evaluated on a 7-point Likert scale based on fear, disgust, and anger. In total, 660 respondents completed the survey. The data were analysed using a factor analysis and general linear model with the respondent as a random factor.

Results

The results show that the strongest fear is triggered by modern threats (electricity, car accidents), while the highest disgust is evoked by ancient threats (body waste products, worms, etc.). Interestingly, disgust does not respond to modern threat stimuli such as toxic substances or radioactivity as these evoke mainly fear and anger. Finally, a distinct response pattern was found for pandemic threats, in which both fear (e.g., of disease and death) and disgust (e.g., of used face masks) are employed.

Discussion

Our study offers valuable insights into the emotional responses to ancestral and modern threats and their adaptation to pandemic challenges. Ancestral threats are not always more powerful stimuli than adequate threats of the modern type, but they function specifically. Thus, snakes and heights as fear-inducing ancestral threats form separate factors in a multivariate analysis, whereas all ancestral disgust stimuli group together. The threat of a pandemic forms a specific category and people process it emotionally and cognitively. These insights contribute to our understanding of human psychology and behavior in an ever-changing world.

Attentional, emotional, and behavioral response toward spiders, scorpions, crabs, and snakes provides no evidence for generalized fear between spiders and scorpions

Spiders are among the animals evoking the highest fear and disgust and such a complex response might have been formed throughout human evolution. Ironically, most spiders do not present a serious threat, so the evolutionary explanation remains questionable. We suggest that other chelicerates, such as scorpions, have been potentially important in the formation and fixation of the spider-like category. In this eye-tracking study, we focused on the attentional, behavioral, and emotional response to images of spiders, scorpions, snakes, and crabs used as task-irrelevant distractors. Results show that spider-fearful subjects were selectively distracted by images of spiders and crabs. Interestingly, these stimuli were not rated as eliciting high fear contrary to the other animals. We hypothesize that spider-fearful participants might have mistaken crabs for spiders based on their shared physical characteristics. In contrast, subjects with no fear of spiders were the most distracted by snakes and scorpions which supports the view that scorpions as well as snakes are prioritized evolutionary relevant stimuli. We also found that the reaction time increased systematically with increasing subjective fear of spiders only when using spiders (and crabs to some extent) but not snakes and scorpions as distractors. The maximal pupil response covered not only the attentional and cognitive response but was also tightly correlated with the fear ratings of the picture stimuli. However, participants' fear of spiders did not affect individual reactions to scorpions measured by the maximal pupil response. We conclude that scorpions are evolutionary fear-relevant stimuli, however, the generalization between scorpions and spiders was not supported in spider-fearful participants. This result might be important for a better understanding of the evolution of spider phobia.

Are vipers prototypic fear-evoking snakes? A cross-cultural comparison of Somalis and Czechs

Snakes are known as highly fear-evoking animals, eliciting preferential attention and fast detection in humans. We examined the human fear response to snakes in the context of both current and evolutionary experiences, conducting our research in the cradle of humankind, the Horn of Africa. This region is characterized by the frequent occurrence of various snake species, including deadly venomous viperids (adders) and elapids (cobras and mambas). We conducted experiments in Somaliland and compared the results with data from Czech respondents to address the still unresolved questions: To which extent is human fear of snakes affected by evolutionary or current experience and local culture? Can people of both nationalities recognize venomous snakes as a category, or are they only afraid of certain species that are most dangerous in a given area? Are respondents of both nationalities equally afraid of deadly snakes from both families (Viperidae, Elapidae)? We employed a well-established picture-sorting approach, consisting of 48 snake species belonging to four distinct groups. Our results revealed significant agreement among Somali as well as Czech respondents. We found a highly significant effect of the stimulus on perceived fear in both populations. Vipers appeared to be the most salient stimuli in both populations, as they occupied the highest positions according to the reported level of subjectively perceived fear. The position of vipers strongly contrasts with the fear ranking of deadly venomous elapids, which were in lower positions. Fear scores of vipers were significantly higher in both populations, and their best predictor was the body width of the snake. The evolutionary, cultural, and cognitive aspects of this phenomenon are discussed.

The bigger the threat, the longer the gaze? A cross-cultural study of Somalis and Czechs

High fear reaction, preferential attention, or fast detection are only a few of the specific responses which snakes evoke in humans. Previous research has shown that these responses are shared amongst several distinct cultures suggesting the evolutionary origin of the response. However, populations from sub-Saharan Africa have been largely missing in experimental research focused on this issue. In this paper, we focus on the effect of snake threat display on human spontaneous attention. We performed an eye-tracking experiment with participants from Somaliland and the Czechia and investigated whether human attention is swayed towards snakes in a threatening posture. Seventy-one Somalis and 71 Czechs were tested; the samples were matched for gender and comparable in age structure and education level. We also investigated the effect of snake morphotype as snakes differ in their threat display. We found that snakes in a threatening posture were indeed gazed upon more than snakes in a relaxed (non-threatening) posture. Further, we found a large effect of snake morphotype as this was especially prominent in cobras, less in vipers, and mostly non-significant in other morphotypes. Finally, despite highly different cultural and environmental backgrounds, the overall pattern of reaction towards snakes was similar in Somalis and Czechs supporting the evolutionary origin of the phenomenon. We concluded that human attention is preferentially directed towards snakes, especially cobras and vipers, in threatening postures.

Animals evoking fear in the Cradle of Humankind: snakes, scorpions, and large carnivores

Theories explain the presence of fears and specific phobias elicited by animals in contemporary WEIRD (Western, educated, industrialized, rich, and democratic) populations by their evolutionary past in Africa. Nevertheless, empirical data about fears of animals in the Cradle of Humankind are still fragmentary. To fill this gap, we examined which local animals are perceived as the most frightening by Somali people, who inhabit a markedly similar environment and the region where humans have evolved. We asked 236 raters to rank 42 stimuli according to their elicited fear. The stimuli were standardized pictures of species representing the local fauna. The results showed that the most frightening animals were snakes, scorpions, the centipede, and large carnivores (cheetahs and hyenas). These were followed up by lizards and spiders. Unlike in Europe, spiders represent less salient stimuli than scorpions for Somali respondents in this study. This conforms to the hypothesis suggesting that fear of spiders was extended or redirected from other chelicerates.

An ethologically based view into human fear

The quality of the defensive response to a threat depends on the elements that trigger the fear response. The current classification system of phobias does not account for this. Here, we analyze the fear-eliciting elements and discern the different types of fears that originate from them. We propose Pain, Disgust, Vasovagal response, Visual-vestibular and postural interactions, Movement and Speed, Distance and Size, Low and mid-level visual features, Smell, and Territory and social status. We subdivide phobias according to the fear-eliciting elements most frequently triggered by them and their impact on behavior. We discuss the implications of a clinical conceptualization of phobias in humans by reconsidering the current nosology. This conceptualization will facilitate finding etiological factors in defensive behavior expression, fine-tuning exposure techniques, and challenging preconceived notions of preparedness. This approach to phobias leads to surprising discoveries and shows how specific responses bear little relation to the interpretation we might later give to them. Dividing fears into their potentially fear-eliciting elements can also help in applying the research principles formulated by the Research Domain Criteria initiative.

Factors associated with human tolerance of snakes in the southeastern United States

Conservation of snakes is influenced by humans’ beliefs, attitudes, and behaviors toward these often-maligned animals. We investigated public attitudes toward snakes through an online survey of undergraduate students (n = 743) at a large public university in a southeastern U.S. state. We used behavioral intent (i.e., how a person would react if they encountered a snake) to assess tolerance of different snake species. We also examined various predictors of tolerance including demographic attributes and a variety of cognitive (e.g., knowledge, value orientations) and affective (e.g., emotions) social-psychological variables. Tolerance of snakes varied based on whether the snake was venomous or non-venomous: about 36% of students said they were likely to kill venomous snakes they encountered, compared with 9% who said they would kill non-venomous snakes and 21% of students who said they would kill snakes whose identity was uncertain. However, most students (54%) could not distinguish between venomous and non-venomous species. Value orientations and emotions were strong predictors of tolerance for snakes, suggesting snake outreach and management strategies should account for both cognitive and affective antecedents of behavior.

Snakebite Envenomation, Attitudes, and Behavior toward Snakes in Banten, Indonesia

Simple Summary

Globally, snake populations are in decline, with conservation efforts hindered by negative attitudes. Meanwhile, snakebite envenomation has been recognized as a serious public health issue, particularly in rural areas where humans and snakes coexist. This study reports the results of a survey conducted in Banten, Indonesia, with the aim of exploring relationships between respondents’ experiences, attitudes towards snakes, and behaviors towards snake populations. Our results indicate that snakebite envenomation presents a real threat in our study area, and that venomous snakes are regarded as highly dangerous. Individuals who had heard of others experiencing venomous snake bites were more likely to want populations of venomous snakes to decrease, and those with negative attitudes towards snakes were also more likely to engage in anti-conservation (“try to kill”) behavior. Women were more fearful than men, and women and those with lower education levels were more negative toward non-venomous pythons, suggesting that tailoring snake conservation efforts to specific groups based on experiences, education level, and attitudes may increase effectiveness. We propose that greater community knowledge of snakes and increases in local resources and preparedness can also contribute to accomplishing both snake conservation and improved public safety through prevention of snakebite envenomation.

Abstract

Snakes are commonly associated with feelings of anxiety or disgust, and snake conservation is often hindered by negative attitudes and perceptions. Although global snake populations are generally in decline, snakebite envenomation (SBE) continues to be recognized as a serious public health issue, particularly in rural areas of tropical and subtropical countries. Data on SBE, a neglected tropical disease, are lacking, and Indonesia, a hotspot of venomous snake diversity, has no snake bite reporting system. We analyzed 127 survey results in Banten, Indonesia with the aim of documenting SBE and exploring the relationships between respondents’ experiences, attitudes, and behaviors toward snakes. Nine percent of respondents had experienced SBE, and knowledge of SBE incidents was associated with negative attitudes toward snake populations, with negative attitudes toward snakes associated with a higher likelihood of anti-conservation behavior. Women were more fearful than men, and women and those with lower education levels were more negative toward pythons (Malayopython reticulatus), suggesting that increased knowledge may aid in snake conservation efforts. Universally negative risk beliefs and attitudes toward venomous snakes indicate a need to reduce the threat of SBE in our study area.

Visual representations of SARS-CoV-2, emotions, and risk perception of COVID-19

BACKGROUND AND AIMS

Before COVID-19 was declared a global pandemic, the U.S. Centers for Disease Control and Prevention (CDC), the National Institute of Allergy and Infectious Diseases (NIAID), and many other organizations published many images of its pathogen (namely SARS-CoV-2) to raise public awareness of the disease. Despite their scientific and aesthetic values, such images may convey metaphoric meanings and cause a subsequent impact on viewers' fear and disgust. This study investigated how exposure to the SARS-CoV-2 images might shape viewers' fear, disgust, and risk perception of COVID-19.

METHODS

Seventy images depicting the SARS-CoV-2 were collected from the websites of CDC, NIAID, and third-party organizations in early 2020. We first showed the images to a group of 492 adults recruited from the Amazon Mechanical Turk (MTurk) and asked them to rate their levels of fear and disgust for each image. Results of this pre-test allowed us to identify images that evoked high, medium, and low levels of fear and disgust, which were then used as treatment stimuli for an online experiment with a national sample of 500 U.S. adults.

RESULTS

Exposure to the selected SARS-CoV-2 images caused different levels of disgust, but not fear, among the members of the national sample. Noticeably, the images evoking the highest level of disgust backfired among those who were least concerned about COVID and caused less fear than images evoking the lowest level of disgust. Image exposure was not associated with risk perception of the disease.

CONCLUSION

This study found that the seemingly objective visualizations of the SARS-CoV-2 are not emotionally neutral. Scientists, agencies, and media professionals should be mindful of the potential emotional impact of science visualizations, such as when creating the iconic image for COVID-19 or other infectious diseases.

Emotions triggered by live arthropods shed light on spider phobia

Spiders are mostly harmless, yet they often trigger high levels of both fear and disgust, and arachnophobia (the phobia of spiders) ranks among the most common specific animal phobias. To investigate this apparent paradox, we turned to the only close relatives of spiders that pose a real danger to humans: scorpions. We adopted a unique methodology in order to assess authentic emotions elicited by arthropods. Over 300 respondents were asked to rate live specimens of 62 arthropod species (including spiders, scorpions, cockroaches, and other insects) based on perceived fear, disgust, and beauty. We found that species' scores on all three scales depended on the higher taxon as well as on body size. Spiders, scorpions, and other arachnids scored the highest in fear and disgust, while beetles and crabs scored the highest in beauty. Moreover, all chelicerates were perceived as one cohesive group, distinct from other arthropods, such as insects or crabs. Based on these results, we hypothesize that the fear of spiders might be triggered by a generalized fear of chelicerates, with scorpions being the original stimulus that signals danger.

The influence of movement on negative and positive emotional responses to animals

Two studies were conducted to explore whether the addition of animal movement would influence the intensity of emotional reactions towards that animal. Both studies compared self-reported emotional reactions with still images and videos for six animal categories (snakes, spiders, rodents, hoofed animals, animals with flippers, and turtles). In Study 1, participants reported fear and disgust to the animal stimuli, which were averaged into a single negative emotion rating. In Study 2, participants reported either fear and disgust or joy and affection to the animal stimuli, which were averaged into either a single negative or positive emotion rating. Upon combining the reported emotions from the two studies, movement was found to increase negative emotion reported to snakes and spiders and decrease negative emotion reported to rodents, hoofed animals, and animals with flippers. Results from Study 2 indicated that movement increased reported positive emotions to all six animal categories. Our findings suggest that animal movement is an important component of emotional reactions to animals.

What Makes Spiders Frightening and Disgusting to People?

The quality of human-animal interactions may crucially influence conservation efforts. Unfortunately, and despite their important roles in the functioning of the ecosystem, some animals are considered notoriously unpopular. Using the forced-choice paradigm, we investigated which cues humans perceive as frightening and disgusting in spiders, one of the most unpleasant animals in the world. The research was carried out with a representative sample of N = 1,015 Slovak adults. We found that perceived fear and disgust of spiders were triggered predominantly by enlarged chelicerae, enlarged abdomen, and the presence of body hair. Longer legs were associated with perceived fear as well; however, the presence of two eyes did not produce any statistical significance in terms of fear. We hope that further research in this field, where additional cues can be manipulated (e.g., color and number of legs), will improve conservation efforts by using an improved reputation of spiders in the eyes of the general public.

Generalization gradients for fear and disgust in human associative learning

Previous research indicates that excessive fear is a critical feature in anxiety disorders; however, recent studies suggest that disgust may also contribute to the etiology and maintenance of some anxiety disorders. It remains unclear if differences exist between these two threat-related emotions in conditioning and generalization. Evaluating different patterns of fear and disgust learning would facilitate a deeper understanding of how anxiety disorders develop. In this study, 32 college students completed threat conditioning tasks, including conditioned stimuli paired with frightening or disgusting images. Fear and disgust were divided into two randomly ordered blocks to examine differences by recording subjective US expectancy ratings and eye movements in the conditioning and generalization process. During conditioning, differing US expectancy ratings (fear vs. disgust) were found only on CS-, which may demonstrated that fear is associated with inferior discrimination learning. During the generalization test, participants exhibited greater US expectancy ratings to fear-related GS1 (generalized stimulus) and GS2 relative to disgust GS1 and GS2. Fear led to longer reaction times than disgust in both phases, and the pupil size and fixation duration for fear stimuli were larger than for disgust stimuli, suggesting that disgust generalization has a steeper gradient than fear generalization. These findings provide preliminary evidence for differences between fear- and disgust-related stimuli in conditioning and generalization, and suggest insights into treatment for anxiety and other fear- or disgust-related disorders.

Attitudes and behaviour toward snakes on the part of Igbo people in southeastern Nigeria

Snakes play a crucial role in natural ecosystems, providing ecological services to people by decreasing rodent populations which may cause disease transmission and impair agricultural production. Despite these benefits, snakes are historically a target of persecution and negative attitudes across cultures, and many of them are threatened. Understanding the predictors of snake-human conflicts is essential to improve conservation efforts. We investigated the degree to which emotions, myth beliefs, experience with snakes (via exposure, bites, and knowledge of mortality from a snakebite), and education would predict attitudes toward snakes in a sample of southeastern Nigerian people. We further examined whether attitudes would predict intentional killing of snakes. Ordinal regression analyses revealed that fear, disgust, and belief in the myth that snakes are evil were related to low tolerance of snakes. More frequent encounters with snakes and higher education were associated with higher tolerance of snakes. Furthermore, higher tolerance of snakes was associated with a reduced likelihood of intentionally killing snakes, even when controlling for the influence of the other psychological and experiential variables. Wildlife management education interventions may be important to change attitudes and decrease intentional killing of snakes.

The Ultimate List of the Most Frightening and Disgusting Animals: Negative Emotions Elicited by Animals in Central European Respondents

Animals have always played an important role in our everyday life. They are given more attention than inanimate objects, which have been adaptive during the evolution of mankind, with some animal species still presenting a real threat to us. In this study, we focused on the species usually evaluated as the scariest and most disgusting in the animal kingdom. We analyzed which characteristics (e.g., weight, potential threat for humans) influence their evaluation in a nonclinical Central European WEIRD population (Western, educated, industrialized, rich, and democratic). The tested animals were divided into two separated sets containing 34 standardized photos evoking predominantly one negative emotion, fear or disgust. The pictures were ranked according to their emotional intensity by 160 adult respondents with high inter-rater agreement. The most fear-eliciting species are mostly large vertebrates (e.g., carnivorans, ungulates, sharks, crocodiles), whereas smaller fear-evoking vertebrates are represented by snakes and invertebrates are represented by arachnids. The most disgust-evoking animals are human endo- and ectoparasites or animals visually resembling them. Humans emotionally react to fear-evoking animals that represent a real threat; however, identifying truly dangerous disgust-evoking animals might be harder. The results also support a somewhat special position of snakes and spiders.

Attentional Processing of Disgust and Fear and Its Relationship With Contamination-Based Obsessive-Compulsive Symptoms: Stronger Response Urgency to Disgusting Stimuli in Disgust-Prone Individuals

Disgust has recently been characterized as a low-urgency emotion, particularly compared to fear. The aim of the present study is to clarify whether behavioral inhibition during disgust engagement is characteristic of a low-urgency emotion and thus indicates self-imposed attentional avoidance in comparison to fear. Therefore, 54 healthy participants performed an emotional go/no-go task with disgust- and fear-relevant as well as neutral pictures. Furthermore, heart rate activity and facial muscle activity on the fear-specific m. corrugator supercilli and the disgust-specific m. levator labii were assessed. The results partially support the temporal urgency hypothesis of disgust. The emotion conditions significantly differed in emotional engagement and in the facial muscle activity of the m. levator labii as expected. However, contrary to our expectations, no differences between the emotion conditions regarding behavioral inhibition as well as heart rate change could be found. Furthermore, individuals with a higher-trait disgust proneness showed faster reactions and higher activity of the m. levator labii in response to disgust stimuli. The results show that different trait levels influence attentional engagement and physiological parameters but have only a small effect on behavioral inhibition.

Venomous snakes elicit stronger fear than nonvenomous ones: Psychophysiological response to snake images

Snakes have been important ambush predators of both primates and human hunter-gatherers throughout their co-evolutionary history. Viperid snakes in particular are responsible for most fatal venomous snakebites worldwide and thus represent a strong selective pressure. They elicit intense fear in humans and are easily recognizable thanks to their distinctive morphotype. In this study, we measured skin resistance (SR) and heart rate (HR) in human subjects exposed to snake pictures eliciting either high fear (10 venomous viperid species) or disgust (10 nonvenomous fossorial species). Venomous snakes subjectively evaluated as frightening trigger a stronger physiological response (higher SR amplitude) than repulsive non-venomous snakes. However, stimuli presented in a block (more intense stimulation) do not trigger a stronger emotional response compared to sequentially presented stimuli (less intense stimulation). There are significant interindividual differences as subjects with high fear of snakes confronted with images of viperid snakes show stronger, longer-lasting, and more frequent changes in SR and higher HR compared to low-fear subjects. Thus, we show that humans demonstrate a remarkable ability to discriminate between dangerous viperids and harmless fossorial snakes, which is also reflected in distinct autonomous body responses.

The Importance of Human Emotions for Wildlife Conservation

Animals have always been important for human life due to the ecological, cultural, and economic functions that they represent. This has allowed building several kinds of relationships that have promoted different emotions in human societies. The objective of this review was to identify the main emotions that humans show toward wildlife species and the impact of such emotions on animal population management. We reviewed academic databases to identify previous studies on this topic worldwide. An analysis of the emotions on wildlife and factors causing them is described in this study. We identified a controversy about these emotions. Large predators such as wolves, coyotes, bears, big felids, and reptiles, such as snakes and geckos, promote mainly anger, fear, and disgust. This is likely due to the perceptions, beliefs, and experiences that societies have historically built around them. However, in some social groups these animals have promoted emotions such as happiness due to their values for people. Likewise, sadness is an emotion expressed for the threatening situations that animals are currently facing. Furthermore, we associated the conservation status of wildlife species identified in the study with human emotions to discuss their relevance for emerging conservation strategies, particularly focused on endangered species promoting ambiguous emotions in different social groups.

Emotional Reaction to Fear- and Disgust-Evoking Snakes: Sensitivity and Propensity in Snake-Fearful Respondents

This paper continues our previous study in which we examined the respondents' reaction to two morphologically different snake stimuli categories - one evoking exclusively fear and another evoking exclusively disgust. Here we acquired Likert-type scale scores of fear and disgust evoked by the same snake stimuli by a total of 330 respondents. Moreover, we collected data about the respondents' age, gender, education, snake fear [Snake Questionnaire (SNAQ)], and disgust propensity [Disgust Scale-Revised (DS-R)], and we analyzed the effect of these variables on the emotional scores (with special focus on snake-fearful respondents). In addition, we collected the SNAQ and DS-R scores from the respondents tested in the previous study using the rank-ordering method to directly compare the results of these two approaches. The results showed that non-fearful respondents give high scores of fear to the fear-eliciting snakes and high scores of disgust to the disgust-eliciting snakes, but they give low scores of the other emotional dimension (disgust/fear) to each. In contrast, snake-fearful respondents not only give higher fear and disgust scores to the respective snake stimuli, but they also give high scores of fear to the disgust-eliciting snakes and high scores of disgust to the fear-eliciting snakes. Both Likert-scale scores and rank-ordering data show that the clear border dividing both snake stimuli categories dissolves when evaluated by the snake-fearful respondents.