Behavioral immune system
The behavioral immune system is a phrase coined by the psychological scientist Mark Schaller to refer to a suite of psychological mechanisms that allow individual organisms to detect the potential presence of infectious parasites or pathogens in their immediate environment, and to engage in behaviors that prevent contact with those objects and individuals.[1][2][3]
The existence of a behavioral immune system has been documented across many animal species, including humans. It is theorized that the mechanisms that comprise the behavioral immune system evolved as a crude first line of defense against disease-causing pathogens.[2]
In humans and animals, activating a physiological immune response to pathogens is effective, but metabolically costly. Immune responses are activated at the expense of other fitness enhancing activities.[4][5] Inflammation after infection can also be harmful to the body (e.g., contribute to diseases of aging).[6][7] In addition to cultural adaptations to avoid pathogens, the behavioral immune system acts as a set of defense mechanisms to protect against pathogens before infection occurs [8][9][10]
Proximate mechanisms
[edit]Mechanisms for the behavioral immune system include sensory processes through which cues connoting the presence of parasitic infections are perceived (e.g., the smell of a foul odor, the sight of pox or pustules), as well as stimulus–response systems through which these sensory cues trigger a cascade of aversive affective, cognitive, and behavioral reactions (e.g., arousal of disgust, automatic activation of cognitions that connote the threat of disease, behavioral avoidance).[2][11]
Sensory components
[edit]Early and current research on behavioral immune system activation has been focused on visual cues or triggers that elicit responses. However, recent work suggests that other sensory modalities may be at work for disease detection.[12]
Smell
[edit]Studies show that olfactory cues of disease elicit disgust and predict pathogen avoidance behaviors.[12] In humans, body odors from diseased individuals are rated less desirable and likeable,[13] and perceived as unhealthier, more intense, and less pleasant.[14] Disgust of body odors is also influenced by the closeness of the source of odor. Odors from family members are rated as less disgusting than body odors from strangers.[15] Experimental studies showed that the presence of aversive odors leads to more prophylactic behaviors, such as more willing condom use[16] and less-direct prophylactic behaviors, like stricter punishment for moral violations.[17]
A new body of work has linked olfactory acuity to disgust and behavioral immune system responses. Given that olfactory cues for pathogen threat are often ambiguous and overgeneralized, a better ability to detect smells would lead to better pathogen avoidance.[12] Recent work suggests that higher olfactory acuity may be associated with higher avoidance motivation.[18]
Taste
[edit]Gustatory stimuli, particularly of spoiled foods, elicit feels of disgust and motivate pathogen avoidance behavior.[19] People with more disgust sensitivity are predicted to have more aversion to novel or foreign foods.[20]
Sight and touch
[edit]Visual cues of pathogen threat have been linked to increases in tactile sensitivity and lead to perceived people with accents as more foreign, especially among individuals with higher disgust sensitivity.[21][22] Disgust sensitivity among individuals is also predictive of preferred amount of personal space.[23]
Overgeneralization
[edit]The “smoke detector principle”[24][25] of evolved systems that regulate protective responses has also been used to describe the behavioral immune systems tendency to overgeneralize.[26] Evolved responses to signals of pathogen threat cannot be perfect and rely on liberal identification criteria.[26] This makes the behavioral immune system susceptible to activating when pathogens are absent. Noninfectious physical and mental abnormalities including elderly appearance,[27][28] disabilities,[29] obesity,[30] and disfigurement[31][32] can act as cues of pathogen presence, when none are present. Even though many false alarms may be triggered in response to these nonharmful cues, the costs associated with behavioral immune activation may be relatively small to the costs of missing a true disease threat.[26]
Respond "Absent" Respond "Present" Stimulus Present Miss Hit Stimulus Absent Correct Rejection False Alarm
Responses
[edit]Disgust
[edit]The pathogen disgust system and the behavioral immune system have been studied separately, but there is recognition that they are functionally the same.[33] Darwin first recognized that the emotion of disgust aided in avoiding "tainted" food.[34] The emotion of disgust has now been recognized as an adaptive function for avoiding pathogen exposure in response to cues of potential pathogen threat. However, disgust to pathogen-related cues should be context-dependent to function adaptively.[35] In one study on the Shuar, an indigenous subsistence-based population with high-pathogen stress, pathogen disgust sensitivity (PDS), measured with a disgust questionnaire, was used to predict pathogen infection. The study found that individual PDS was negatively correlated with pathogen infection predictive of the hypothesis that disgust acts as a pathogen defense mechanism sensitive to local costs and benefits of avoidance and infection.[35]
Functional flexibility
[edit]Functional flexibility is a term used to describe the ability of the behavioral immune system to adjust responses to pathogens depending on the individual’s infection-related threat and infection-relating vulnerability. Like many evolved threat management systems, the behavioral immune system is sensitive to the costs and benefits of pathogen avoidance.[36][9][37]
Reactive and proactive
[edit]Two categories of outputs can be generated by the behavioral immune system; reactive and proactive responses[26] Reactive responses occur in response to the presence of cues connoting an immediate infection risk. The responses generally take the form of avoidant or prophylactic behaviors.[38][39] These can include restricted sexual attitudes,[40][41][42] positivity towards condom use,[43] and avoidance of people with cues associated with illness.[29][44]
Proactive responses occur in response to the long-term and persistent threat of pathogens.[26] Across species, proactive management of pathogen threat can be seen in hygiene behaviors to mitigate reoccurring bacterial and viral threats.[45] Additionally, proactive responses can be seen in the importance placed on a potential mate's physical attractiveness, symmetry, and secondary sex-characteristics which are all indicators of health, and healthy people are less likely to carry disease.[46][47][48][49][50]
Influences on social psychology
[edit]Two social consequences of activating the behavioral immune system according to Ackerman et al., are "1. increased aversion and avoidance of unfamiliar and outgroup targets and 2. strengthened cohesion with familiar and ingroup targets."[26]
Interpersonal perception
[edit]Interpersonal perception is influenced by the behavioral immune system due to the early stage cognitive processes recruited for identifying pathogenic threat and the risks associated with interpersonal contagion.
Visual attention is one these early cognitive process recruited toward cues of pathogen threat and perceivers find it more difficult to visually disengage from faces possessing these cues, like physical abnormalities, even if no threat is present .[31]
The behavioral immune system may also cause people who perceive greater pathogen threat to report greater distinctions between ingroup and outgroup members, and classify strangers as more threatening.[51][28][21]
Judgment and decision-making
[edit]Judgments, inferences, and decisions about people and objects are other cognitive processes recruited by the behavioral immune system that are affected by pathogen threat. These processes motivative choices that help perceivers avoid unfamiliar stimuli that may include contamination dangers.[52][53]
Examples of the influence perceived pathogen threat has on these processes include: avoidance of controllable risk,[54] reduced desire for social affiliation,[55] and devaluation of consumer products previously handled by strangers.[56]
Additional lines of research on the behavioral immune system have shown that people engage in more reticent and conservative forms of behavior under conditions in which they feel more vulnerable to disease transmission. For instance, when the potential threat of disease is made salient, people tend to be less extraverted or sociable.[57]
Close relationships
[edit]The behavioral immune system influences potential mating choices and sexual behavior. High concern for chronic pathogen threats and environments with greater pathogen stress increase the value an individual places on physical attractiveness,[46][49][58] and lessens preference for mates with physical abnormality or sex-divergent features.[59][60] Among perceivers, cues of pathogen prevalence (real or perceived)[26] are associated with more restricted sexual pursuits and attitudes to avoid infection.[40][42] Opposite, more sexual opportunism is found in individuals with perceived insufficient immune systems for survival in environments with higher pathogen stress.[47]
Stereotyping and prejudice
[edit]Another outcome of behavioral immune system activity is prejudice and stereotyping of outgroup members. Individuals at higher risk of pathogen infection are more likely to stigmatize other individuals possessing cues of disease, real or perceived.[44][61][62][63][64][28][65]
The disease–avoidant processes that characterize the behavioral immune system have been shown to contribute to prejudices against obese individuals, elderly individuals, and people with physical disfigurements or disabilities.[66][67][27] In addition, the behavioral immune system appears to contribute to xenophobia and ethnocentrism.[64][68] This can be seen among pregnant women, which face higher infection-related vulnerability, that express an increase ethnocentric views.[68] These attitudes might function as a way to avoid people with new pathogens or practices that local practices are unsuited to manage.[26] One implication is that these prejudices tend to be exaggerated under conditions in which people feel especially vulnerable to the potential transmission of infectious diseases.
Group processes and cultural norms
[edit]The behavioral immune system has the ability to impact group intragroup attitudes and behaviors. Research shows that pathogen stress is associated with higher social conformity[69][70] and higher levels of disgust, which aids in pathogen avoidance[56][11][71][39] and predictive of greater sensitivity to moral violations.[26]
Some studies have used the behavioral immune system to explain the root of more fundamental dimensions of culture including the variance in: individualism/collectivism,[72] social and political orientation,[73][74][58] and religious beliefs,[75][76] in response to levels of pathogen stress.
Collectivist cultures defined by behavioral manifestations such as ethnocentrism and social conformity which aid in pathogen avoidance, have been correlated with higher historical pathogen stress compared to individualistic cultures.[72] Given that there might be benefits associated with individualistic cultures in the societies they create, individualist cultures also confer greater pathogen exposure. In environments with greater pathogen stress, the behavioral manifestations of collectivism that help avoid pathogens may serve an adaptive advantage.[72]
Critiques of in-group preference
[edit]In-group preferences defined by the degree to which people prefer interacting with and investing in family, friends, and in group members has been suggested to be a function of the behavioral immune system in order to defend against pathogens.[72][10][76] However, these studies on cross-population level data have been criticized for not incorporating non-independence variables and alternative hypotheses.[77][78][79] In a follow up study, using measures the same measure for in-group preference, Hofstede's collectivism, Van de Vliert's in-group favoritism, and Fincher and Thornhill's strength of family ties, find that less government effectiveness is a better predictor of in-group preference than pathogen stress.[80]
Implications for immunology
[edit]Complimentary
[edit]Some research suggests that the behavioral immune system has implications for the functioning of the physiological immune system (PIS) too. One study found that the mere visual perception of diseased-looking people stimulated white blood cells to respond more aggressively to infection (as indicated by the production of the proinflammatory cytokine Interleukin 6 in response to a bacterial stimulus).[81]
In other studies, exposure to visual environmental pathogen cues, in addition to increased feelings of disgust and prejudice responses associated with the behavioral immune system (BIS), upregulate oral and blood immune inflammatory biomarkers.[82][83][84] This body of literature suggests that visual cues connected to the BIS may invoke PIS responses when pathogen threat is immediate.[12]
Compensatory
[edit]In the absence of an immediate pathogen threat, the PIS and BIS may not be complimentary, but compensatory. For example, in an experiment that stimulated release of proinflammatory cytokines (IL-6, IL-1b, TNF-alpha) collected from healthy individuals, were not related to self-reported germ aversion, but in-vivo IL-6 levels were negatively correlated to germ aversion and perceived longevity. This research may highlight the function of the BIS for long-term health by decreasing proinflammatory responses (function of IL-6), linked to diseases of aging.[85]
Research also indicates that immune-relevant interventions which target pathogen transmission can interrupt behavioral responses. For example, receiving a flu vaccination or washing one's hands can reduce the extent of negative interpersonal and intergroup attitudes elicited by disease cues and concerns.[86]
Sickness behavior
[edit]The large body of literature on the behavioral immune system is focused on behaviors triggered by pathogen cues in the environment and the role disgust plays in mitigating exposure before infection. However, the emotion associated with being sick, lassitude, that is triggered by an active infection may also act as behavioral defense mechanism against pathogens. One study suggests that lassitude may help fight against an active infection by:
- reducing energetically expensive movement to make more energy available to the immune system.[87]
- reducing exposure to additional infections and injuries that would increase the immune systems' workload.[87]
- promoting thermoregulatory behaviors that facilitate immunity.[87]
- regulating food consumption to be beneficial for the host but detrimental to pathogens.[87]
- deploying strategies that elicit caregiving behavior from social allies.[87]
COVID-19
[edit]The behavioral immune system's prediction of ingroup favoritism and ethnocentric beliefs has been applied to individual beliefs during the global pandemic, COVID-19. In several studies, individuals who scored higher in dispositional worry about disease reported stronger preference for restrictive travel bans on several regions of Asia. One study found that as COVID-19 cases increased, individuals reported higher concern about contracting the virus and showed greater levels of Right-Wing Authoritarianism, including conservatism and traditionalism.[88] Experimental increase of pandemic salience also increased support of travel bans on high risk nation (China and Italy), but not on low risk nations like Canada and Mexico.[89] Another study measuring individual perceived vulnerability to disease (PVD) and responses to COVID-19 found that higher PVD was positively associated with stronger reactions to the threat of COVID-19, including increased anxiety, perceptions that people should alter their typical behavior, and self-reported importance of social distancing.[90]
References
[edit]- ^ Schaller M (2006). "Parasites, behavioral defenses, and the social psychological mechanisms through which cultures are evoked". Psychological Inquiry. 17 (2): 96–101. doi:10.1207/s15327965pli1702_2. S2CID 219729311.
- ^ a b c Schaller M, Duncan LA (2007). "The behavioral immune system: Its evolution and social psychological implications". In Forgas JP, Haselton MG, von Hippel W (eds.). Evolution and the social mind: Evolutionary psychology and social cognition. New York: Psychology Press. pp. 293–307.
- ^ Schaller M, Park JH (2011). "The behavioral immune system (and why it matters)". Current Directions in Psychological Science. 20 (2): 99–103. CiteSeerX 10.1.1.459.1601. doi:10.1177/0963721411402596. S2CID 39930315.
- ^ Dantzer R (March 2001). "Cytokine-induced sickness behavior: where do we stand?". Brain, Behavior, and Immunity. 15 (1): 7–24. doi:10.1006/brbi.2000.0613. PMID 11259077. S2CID 3187017.
- ^ Hart BL (June 1988). "Biological basis of the behavior of sick animals". Neuroscience and Biobehavioral Reviews. 12 (2): 123–37. doi:10.1016/s0149-7634(88)80004-6. PMID 3050629. S2CID 17797005.
- ^ Conner EM, Grisham MB (April 1996). "Inflammation, free radicals, and antioxidants". Nutrition. 12 (4): 274–7. doi:10.1016/s0899-9007(96)00000-8. PMID 8862535.
- ^ Khansari N, Shakiba Y, Mahmoudi M (January 2009). "Chronic inflammation and oxidative stress as a major cause of age-related diseases and cancer". Recent Patents on Inflammation & Allergy Drug Discovery. 3 (1): 73–80. doi:10.2174/187221309787158371. PMID 19149749.
- ^ Murray DR, Schaller M (2016). "The Behavioral Immune System". Advances in Experimental Social Psychology. Vol. 53. Elsevier. pp. 75–129. doi:10.1016/bs.aesp.2015.09.002. ISBN 978-0-12-804737-8.
- ^ a b Schaller M, Park JH (April 2011). "The Behavioral Immune System (and Why It Matters)". Current Directions in Psychological Science. 20 (2): 99–103. doi:10.1177/0963721411402596. ISSN 0963-7214. S2CID 39930315.
- ^ a b Schaller M (December 2011). "The behavioural immune system and the psychology of human sociality". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 366 (1583): 3418–26. doi:10.1098/rstb.2011.0029. PMC 3189350. PMID 22042918.
- ^ a b Oaten M, Stevenson RJ, Case TI (March 2009). "Disgust as a disease-avoidance mechanism". Psychological Bulletin. 135 (2): 303–21. doi:10.1037/a0014823. PMID 19254082.
- ^ a b c d Murray DR, Prokosch ML, Airington Z (2019-02-07). "PsychoBehavioroimmunology: Connecting the Behavioral Immune System to Its Physiological Foundations". Frontiers in Psychology. 10: 200. doi:10.3389/fpsyg.2019.00200. PMC 6378957. PMID 30804853.
- ^ Regenbogen C, Axelsson J, Lasselin J, Porada DK, Sundelin T, Peter MG, et al. (June 2017). "Behavioral and neural correlates to multisensory detection of sick humans". Proceedings of the National Academy of Sciences of the United States of America. 114 (24): 6400–6405. doi:10.1073/pnas.1617357114. PMC 5474783. PMID 28533402.
- ^ Olsson MJ, Lundström JN, Kimball BA, Gordon AR, Karshikoff B, Hosseini N, et al. (March 2014). "The scent of disease: human body odor contains an early chemosensory cue of sickness". Psychological Science. 25 (3): 817–23. doi:10.1177/0956797613515681. PMID 24452606. S2CID 14530226.
- ^ Stevenson RJ, Repacholi BM (2005). "Does the source of an interpersonal odour affect disgust? A disease risk model and its alternatives". European Journal of Social Psychology. 35 (3): 375–401. doi:10.1002/ejsp.263. ISSN 0046-2772.
- ^ Tybur JM, Bryan AD, Magnan RE, Hooper AE (April 2011). "Smells like safe sex: olfactory pathogen primes increase intentions to use condoms". Psychological Science. 22 (4): 478–80. doi:10.1177/0956797611400096. PMID 21350181. S2CID 31099982.
- ^ Schnall S, Haidt J, Clore GL, Jordan AH (August 2008). "Disgust as embodied moral judgment". Personality & Social Psychology Bulletin. 34 (8): 1096–109. doi:10.1177/0146167208317771. PMC 2562923. PMID 18505801.
- ^ Fay AJ, Bovier ER (2018-02-24). "Testing a Curvilinear Relationship between Chemosensory Responsivity and Avoidance Motivation". Adaptive Human Behavior and Physiology. 4 (2): 207–222. doi:10.1007/s40750-018-0088-1. ISSN 2198-7335. S2CID 148883832.
- ^ Tybur JM, Laakasuo M, Ruff J, Klauke F (September 2016). "How pathogen cues shape impressions of foods: the omnivore's dilemma and functionally specialized conditioning". Evolution and Human Behavior. 37 (5): 376–386. doi:10.1016/j.evolhumbehav.2016.03.002. ISSN 1090-5138.
- ^ Al-Shawaf L, Lewis DM, Alley TR, Buss DM (February 2015). "Mating strategy, disgust, and food neophobia". Appetite. 85: 30–5. doi:10.1016/j.appet.2014.10.029. hdl:11693/22547. PMID 25450899. S2CID 14110094.
- ^ a b Reid SA, Zhang J, Anderson GL, Gasiorek J, Bonilla D, Peinado S (September 2012). "Parasite primes make foreign-accented English sound more distant to people who are disgusted by pathogens (but not by sex or morality)". Evolution and Human Behavior. 33 (5): 471–478. doi:10.1016/j.evolhumbehav.2011.12.009. ISSN 1090-5138.
- ^ Hunt DF, Cannell G, Davenhill NA, Horsford SA, Fleischman DS, Park JH (July 2017). "Making your skin crawl: The role of tactile sensitivity in disease avoidance" (PDF). Biological Psychology. 127: 40–45. doi:10.1016/j.biopsycho.2017.04.017. PMID 28478137. S2CID 7894884.
- ^ Park JH (August 2015). "Introversion and human-contaminant disgust sensitivity predict personal space" (PDF). Personality and Individual Differences. 82: 185–187. doi:10.1016/j.paid.2015.03.030. hdl:1983/aa8c5c1c-f834-432d-9885-b5d44fff50d4. ISSN 0191-8869.
- ^ Haselton MG, Nettle D (February 2006). "The paranoid optimist: an integrative evolutionary model of cognitive biases". Personality and Social Psychology Review. 10 (1): 47–66. doi:10.1207/s15327957pspr1001_3. PMID 16430328. S2CID 5725102.
- ^ Nesse RM (2018-12-04). "The smoke detector principle: Signal detection and optimal defense regulation". Evolution, Medicine, and Public Health. 2019 (1): 1. doi:10.1093/emph/eoy034. PMC 6343816. PMID 30697424.
- ^ a b c d e f g h i Ackerman JM, Hill SE, Murray DR (2018-01-26). "The behavioral immune system: Current concerns and future directions". Social and Personality Psychology Compass. 12 (2): e12371. doi:10.1111/spc3.12371. hdl:2027.42/142457. ISSN 1751-9004.
- ^ a b Duncan LA, Schaller M (October 27, 2009). "Prejudicial Attitudes Toward Older Adults May Be Exaggerated When People Feel Vulnerable to Infectious Disease: Evidence and Implications". Analyses of Social Issues and Public Policy. 9 (1): 97–115. doi:10.1111/j.1530-2415.2009.01188.x.
- ^ a b c Miller SL, Maner JK (June 2012). "Overperceiving disease cues: the basic cognition of the behavioral immune system". Journal of Personality and Social Psychology. 102 (6): 1198–213. doi:10.1037/a0027198. PMID 22329656.
- ^ a b Schaller M, Park J, Faulkner J (January 2003). "Prehistoric dangers and contemporary prejudices". European Review of Social Psychology. 14 (1): 105–137. doi:10.1080/10463280340000036. ISSN 1046-3283. S2CID 30987296.
- ^ Lund EM, Miller SL (July 2014). "Is obesity un-American? Disease concerns bias implicit perceptions of national identity". Evolution and Human Behavior. 35 (4): 336–340. doi:10.1016/j.evolhumbehav.2014.03.004. ISSN 1090-5138.
- ^ a b Ackerman JM, Becker DV, Mortensen CR, Sasaki T, Neuberg SL, Kenrick DT (May 2009). "A pox on the mind: Disjunction of attention and memory in the processing of physical disfigurement". Journal of Experimental Social Psychology. 45 (3): 478–485. doi:10.1016/j.jesp.2008.12.008. PMC 2699287. PMID 19578547.
- ^ Miller SL, Maner JK (December 2011). "Sick body, vigilant mind: the biological immune system activates the behavioral immune system". Psychological Science. 22 (12): 1467–71. doi:10.1177/0956797611420166. PMID 22058109. S2CID 206585861.
- ^ Lieberman D, Patrick C (2014). "Are the behavioral immune system and pathogen disgust identical?". Evolutionary Behavioral Sciences. 8 (4): 244–250. doi:10.1037/ebs0000018. ISSN 2330-2933.
- ^ Darwin C (2009). "Disdain — Contempt — Disgust — Guilt — Pride, Etc. — Helplessness — Patience — Affirmation and Negation". In Darwin F (ed.). The Expression of the Emotions in Man and Animals. Cambridge: Cambridge University Press. pp. 265–292. doi:10.1017/cbo9780511694110.013. ISBN 978-0-511-69411-0.
- ^ a b Cepon-Robins TJ, Blackwell AD, Gildner TE, Liebert MA, Urlacher SS, Madimenos FC, et al. (February 2021). "Pathogen disgust sensitivity protects against infection in a high pathogen environment". Proceedings of the National Academy of Sciences of the United States of America. 118 (8): e2018552118. doi:10.1073/pnas.2018552118. PMC 7923589. PMID 33597300.
- ^ Schaller M, Neuberg SL (2012). "Danger, Disease, and the Nature of Prejudice(s)". Advances in Experimental Social Psychology. Vol. 46. Elsevier. pp. 1–54. doi:10.1016/b978-0-12-394281-4.00001-5. ISBN 978-0-12-394281-4.
- ^ Schaller M, Park JH, Kenrick DT (2007-04-05). "Human evolution and social cognition". Oxford Handbooks Online: 491–504. doi:10.1093/oxfordhb/9780198568308.013.0033. ISBN 978-0198568308.
- ^ Curtis V, de Barra M, Aunger R (February 2011). "Disgust as an adaptive system for disease avoidance behaviour". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 366 (1563): 389–401. doi:10.1098/rstb.2011.0002. PMC 3013466. PMID 21199843.
- ^ a b Tybur JM, Lieberman D, Kurzban R, DeScioli P (January 2013). "Disgust: evolved function and structure". Psychological Review. 120 (1): 65–84. doi:10.1037/a0030778. PMID 23205888.
- ^ a b Duncan LA, Schaller M, Park JH (October 2009). "Perceived vulnerability to disease: Development and validation of a 15-item self-report instrument". Personality and Individual Differences. 47 (6): 541–6. doi:10.1016/j.paid.2012.08.021.
- ^ Murray DR, Jones DN, Schaller M (January 2013). "Perceived threat of infectious disease and its implications for sexual attitudes". Personality and Individual Differences. 54 (1): 103–108. doi:10.1016/j.paid.2012.08.021. ISSN 0191-8869.
- ^ a b Schaller M, Murray DR (July 2008). "Pathogens, personality, and culture: disease prevalence predicts worldwide variability in sociosexuality, extraversion, and openness to experience". Journal of Personality and Social Psychology. 95 (1): 212–21. CiteSeerX 10.1.1.476.4335. doi:10.1037/0022-3514.95.1.212. PMID 18605861.
- ^ Tybur JM, Bryan AD, Lieberman D, Hooper AE, Merriman LA (August 2011). "Sex differences and sex similarities in disgust sensitivity". Personality and Individual Differences. 51 (3): 343–348. doi:10.1016/j.paid.2011.04.003. ISSN 0191-8869.
- ^ a b Park JH, Schaller M, Crandall CS (November 2007). "Pathogen-avoidance mechanisms and the stigmatization of obese people". Evolution and Human Behavior. 28 (6): 410–414. doi:10.1016/j.evolhumbehav.2007.05.008. ISSN 1090-5138.
- ^ Curtis V, Biran A (2001). "Dirt, disgust, and disease. Is hygiene in our genes?". Perspectives in Biology and Medicine. 44 (1): 17–31. doi:10.1353/pbm.2001.0001. PMID 11253302. S2CID 15675303.
- ^ a b Gangestad SW, Buss DM (March 1993). "Pathogen prevalence and human mate preferences". Ethology and Sociobiology. 14 (2): 89–96. doi:10.1016/0162-3095(93)90009-7. hdl:2027.42/30928. ISSN 0162-3095.
- ^ a b Hill SE, Prokosch ML, DelPriore DJ (August 2015). "The impact of perceived disease threat on women's desire for novel dating and sexual partners: is variety the best medicine?". Journal of Personality and Social Psychology. 109 (2): 244–61. doi:10.1037/pspi0000024. PMID 26030057.
- ^ Jones BC, Feinberg DR, Watkins CD, Fincher CL, Little AC, DeBruine LM (2012-10-23). "Pathogen disgust predicts women's preferences for masculinity in men's voices, faces, and bodies". Behavioral Ecology. 24 (2): 373–379. doi:10.1093/beheco/ars173. ISSN 1465-7279.
- ^ a b Lee AJ, Zietsch BP (December 2011). "Experimental evidence that women's mate preferences are directly influenced by cues of pathogen prevalence and resource scarcity". Biology Letters. 7 (6): 892–5. doi:10.1098/rsbl.2011.0454. PMC 3210674. PMID 21697166.
- ^ Hugenberg K, Young SG, Sacco DF, Bernstein MJ (2011-07-28). "Social Categorization Influences Face Perception and Face Memory". Oxford Handbooks Online. doi:10.1093/oxfordhb/9780199559053.013.0013.
- ^ Makhanova A, Miller SL, Maner JK (January 2015). "Germs and the out-group: Chronic and situational disease concerns affect intergroup categorization". Evolutionary Behavioral Sciences. 9 (1): 8–19. doi:10.1037/ebs0000028. ISSN 2330-2933.
- ^ Inbar, Yoel; Pizarro, David (2014), "Pollution and Purity in Moral and Political Judgment", Advances in Experimental Moral Psychology, Bloomsbury Academic, pp. 111–129, doi:10.5040/9781472594150.ch-006, ISBN 978-1-4725-0938-3
- ^ Peng M, Chang L, Zhou R (March 2013). "Physiological and behavioral responses to strangers compared to friends as a source of disgust". Evolution and Human Behavior. 34 (2): 94–98. doi:10.1016/j.evolhumbehav.2012.10.002. ISSN 1090-5138.
- ^ Prokosch ML, Gassen J, Ackerman JM, Hill SE (October 2019). "Caution in the time of cholera: Pathogen threats decrease risk tolerance". Evolutionary Behavioral Sciences. 13 (4): 311–334. doi:10.1037/ebs0000160. ISSN 2330-2933. S2CID 92163234.
- ^ Sacco DF, Young SG, Hugenberg K (December 2014). "Balancing competing motives: adaptive trade-offs are necessary to satisfy disease avoidance and interpersonal affiliation goals". Personality & Social Psychology Bulletin. 40 (12): 1611–23. doi:10.1177/0146167214552790. PMID 25278107. S2CID 8082873.
- ^ a b Huang JY, Ackerman JM, Newman GE (October 2017). "Catching (Up with) Magical Contagion: A Review of Contagion Effects in Consumer Contexts". Journal of the Association for Consumer Research. 2 (4): 430–443. doi:10.1086/693533. ISSN 2378-1815. S2CID 51791428.
- ^ Mortensen CR, Becker DV, Ackerman JM, Neuberg SL, Kenrick DT (March 2010). "Infection breeds reticence: the effects of disease salience on self-perceptions of personality and behavioral avoidance tendencies". Psychological Science. 21 (3): 440–7. doi:10.1177/0956797610361706. hdl:1721.1/67706. PMID 20424082. S2CID 2791764.
- ^ a b White AE, Kenrick DT, Neuberg SL (December 2013). "Beauty at the ballot box: disease threats predict preferences for physically attractive leaders". Psychological Science. 24 (12): 2429–36. doi:10.1177/0956797613493642. PMID 24121414. S2CID 20502884.
- ^ Lee AJ, Brooks RC, Potter KJ, Zietsch BP (November 2015). "Pathogen disgust sensitivity and resource scarcity are associated with mate preference for different waist-to-hip ratios, shoulder-to-hip ratios, and body mass index". Evolution and Human Behavior. 36 (6): 480–488. doi:10.1016/j.evolhumbehav.2015.07.002. hdl:1893/28703. ISSN 1090-5138.
- ^ Little AC, DeBruine LM, Jones BC (July 2011). "Exposure to visual cues of pathogen contagion changes preferences for masculinity and symmetry in opposite-sex faces". Proceedings. Biological Sciences. 278 (1714): 2032–9. doi:10.1098/rspb.2010.1925. PMC 3107643. PMID 21123269.
- ^ Navarrete CD, Fessler DM (July 2006). "Disease avoidance and ethnocentrism: the effects of disease vulnerability and disgust sensitivity on intergroup attitudes". Evolution and Human Behavior. 27 (4): 270–282. doi:10.1016/j.evolhumbehav.2005.12.001. ISSN 1090-5138.
- ^ Mortensen CR, Becker DV, Ackerman JM, Neuberg SL, Kenrick DT (March 2010). "Infection breeds reticence: the effects of disease salience on self-perceptions of personality and behavioral avoidance tendencies". Psychological Science. 21 (3): 440–7. doi:10.1177/0956797610361706. hdl:1721.1/67706. PMID 20424082. S2CID 2791764.
- ^ Huang JY, Sedlovskaya A, Ackerman JM, Bargh JA (December 2011). "Immunizing against prejudice: effects of disease protection on attitudes toward out-groups". Psychological Science. 22 (12): 1550–6. doi:10.1177/0956797611417261. hdl:1721.1/77620. PMID 22058107. S2CID 18413566.
- ^ a b Faulkner J, Schaller M, Park JH, Duncan LA (2004). "Evolved Disease–Avoidance Mechanisms and Contemporary Xenophobic Attitudes". Group Processes and Intergroup Relations. 7 (4): 333–53. CiteSeerX 10.1.1.1018.9323. doi:10.1177/1368430204046142. S2CID 28558930.
- ^ Crandall CS, Moriarty D (March 1995). "Physical illness stigma and social rejection". The British Journal of Social Psychology. 34 ( Pt 1) (1): 67–83. doi:10.1111/j.2044-8309.1995.tb01049.x. PMID 7735733.
- ^ Park JH, Faulkner J, Schaller M (June 2003). "Evolved disease-avoidance processes and contemporary anti-social behavior: Prejudicial attitudes and avoidance of people with physical disabilities". Journal of Nonverbal Behavior. 27 (2): 65–87. doi:10.1023/A:1023910408854. ISSN 1573-3653. S2CID 41615132.
- ^ Park J, Schaller M, Crandall CS (2007). "Pathogen-avoidance mechanisms and the stigmatization of obese people" (PDF). Evolution and Human Behavior. 28 (6): 410–4. doi:10.1016/j.evolhumbehav.2007.05.008.
- ^ Murray DR, Schaller M (2011-11-20). "Threat(s) and conformity deconstructed: Perceived threat of infectious disease and its implications for conformist attitudes and behavior". European Journal of Social Psychology. 42 (2): 180–188. doi:10.1002/ejsp.863. ISSN 0046-2772.
- ^ Wu BP, Chang L (July 2012). "The social impact of pathogen threat: How disease salience influences conformity". Personality and Individual Differences. 53 (1): 50–54. doi:10.1016/j.paid.2012.02.023. ISSN 0191-8869.
- ^ Haidt J, McCauley C, Rozin P (1994). "Disgust Scale". PsycTESTS Dataset. doi:10.1037/t12177-000.
- ^ a b c d Fincher CL, Thornhill R, Murray DR, Schaller M (June 2008). "Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism". Proceedings. Biological Sciences. 275 (1640): 1279–85. doi:10.1098/rspb.2008.0094. PMC 2602680. PMID 18302996.
- ^ Murray DR, Schaller M, Suedfeld P (2013-05-01). "Pathogens and politics: further evidence that parasite prevalence predicts authoritarianism". PLOS ONE. 8 (5): e62275. Bibcode:2013PLoSO...862275M. doi:10.1371/journal.pone.0062275. PMC 3641067. PMID 23658718.
- ^ Terrizzi JA, Shook NJ, McDaniel MA (March 2013). "The behavioral immune system and social conservatism: a meta-analysis". Evolution and Human Behavior. 34 (2): 99–108. doi:10.1016/j.evolhumbehav.2012.10.003. ISSN 1090-5138. S2CID 11812927.
- ^ Fincher CL, Thornhill R (November 2008). "Assortative sociality, limited dispersal, infectious disease and the genesis of the global pattern of religion diversity". Proceedings. Biological Sciences. 275 (1651): 2587–94. doi:10.1098/rspb.2008.0688. PMC 2605802. PMID 18664438.
- ^ a b Fincher CL, Thornhill R (April 2012). "Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity" (PDF). The Behavioral and Brain Sciences. 35 (2): 61–79. doi:10.1017/s0140525x11000021. PMID 22289223. S2CID 54624893.
- ^ Thornhill R, Fincher CL (July 2013). "Commentary on Hackman, J., & Hruschka, D. (2013). Fast life histories, not pathogens, account for state-level variation in homicide, child maltreatment, and family ties in the U.S. Evolution and Human Behavior, 34,118–124". Evolution and Human Behavior. 34 (4): 314–315. doi:10.1016/j.evolhumbehav.2013.03.006. ISSN 1090-5138.
- ^ Van de Vliert E, Postmes T (April 2012). "Climato-economic livability predicts societal collectivism and political autocracy better than parasitic stress does". The Behavioral and Brain Sciences. 35 (2): 94–5. doi:10.1017/s0140525x11001075. PMID 22289160. S2CID 13449531.
- ^ Currie TE, Mace R (April 2012). "Analyses do not support the parasite-stress theory of human sociality" (PDF). The Behavioral and Brain Sciences. 35 (2): 83–5. doi:10.1017/s0140525x11000963. PMID 22289294. S2CID 302233.
- ^ Hruschka DJ, Henrich J (2013-05-21). "Institutions, parasites and the persistence of in-group preferences". PLOS ONE. 8 (5): e63642. Bibcode:2013PLoSO...863642H. doi:10.1371/journal.pone.0063642. PMC 3660589. PMID 23704926.
- ^ Schaller M, Miller GE, Gervais WM, Yager S, Chen E (May 2010). "Mere visual perception of other people's disease symptoms facilitates a more aggressive immune response". Psychological Science. 21 (5): 649–52. doi:10.1177/0956797610368064. PMID 20483842. S2CID 58423.
- ^ Stevenson RJ, Hodgson D, Oaten MJ, Barouei J, Case TI (July 2011). "The effect of disgust on oral immune function". Psychophysiology. 48 (7): 900–7. doi:10.1111/j.1469-8986.2010.01165.x. PMID 21166686.
- ^ Stevenson RJ, Hodgson D, Oaten MJ, Moussavi M, Langberg R, Case TI, Barouei J (October 2012). "Disgust elevates core body temperature and up-regulates certain oral immune markers". Brain, Behavior, and Immunity. 26 (7): 1160–8. doi:10.1016/j.bbi.2012.07.010. PMID 22841694. S2CID 34237534.
- ^ Stevenson RJ, Hodgson D, Oaten MJ, Sominsky L, Mahmut M, Case TI (2015-07-01). "Oral Immune Activation by Disgust and Disease-Related Pictures". Journal of Psychophysiology. 29 (3): 119–129. doi:10.1027/0269-8803/a000143. ISSN 0269-8803.
- ^ Gassen J, Prokosch ML, Makhanova A, Eimerbrink MJ, White JD, Proffitt Leyva RP, et al. (2018-09-20). "Behavioral immune system activity predicts downregulation of chronic basal inflammation". PLOS ONE. 13 (9): e0203961. Bibcode:2018PLoSO..1303961G. doi:10.1371/journal.pone.0203961. PMC 6147464. PMID 30235317.
- ^ Huang JY, Sedlovskaya A, Ackerman JM, Bargh JA (December 2011). "Immunizing against prejudice: effects of disease protection on attitudes toward out-groups". Psychological Science. 22 (12): 1550–6. doi:10.1177/0956797611417261. hdl:1721.1/77620. PMID 22058107. S2CID 18413566.
- ^ a b c d e Schrock JM, Snodgrass JJ, Sugiyama LS (January 2020). "Lassitude: The emotion of being sick". Evolution and Human Behavior. 41 (1): 44–57. doi:10.1016/j.evolhumbehav.2019.09.002. ISSN 1090-5138. S2CID 203480861.
- ^ Pazhoohi F, Kingstone A (2021). "Associations of political orientation, xenophobia, right-wing authoritarianism, and concern of COVID-19: Cognitive responses to an actual pathogen threat". Personality and Individual Differences. 111081. doi:10.1016/j.paid.2021.111081. PMC 9756797.
- ^ Moran JB, Goh JX, Kerry N, Murray DR (April 2021). "Outbreaks and Outgroups: Three Tests of the Relationship Between Disease Avoidance Motives and Xenophobia During an Emerging Pandemic". Evolutionary Psychological Science. 7 (4): 419–429. doi:10.1007/s40806-021-00283-z. PMC 8060690. PMID 33903849.
- ^ Makhanova A, Shepherd MA (December 2020). "Behavioral immune system linked to responses to the threat of COVID-19". Personality and Individual Differences. 167: 110221. doi:10.31234/osf.io/6dq3g. PMC 7328593. PMID 32834281.