Introduction to the special issue: evolutionary and biopsychosocial perspectives on sickness communication.

Here, we introduce the EMPH special issue on Evolutionary and Biopsychosocial Perspectives on Sickness Communication. This Commentary provides an overview of each article and places them in the wider context of sickness as a social phenomenon with verbal and nonverbal signals. This Commentary, and the special issue, in general, calls for greater attention to these signals that can affect pathogen transmission and may be at the evolutionary root of our caregiving systems and behaviours.

Investigating the linkages between food insecurity, psychological distress, and poor sleep outcomes among U.S. college students.

OBJECTIVE: Research overwhelmingly demonstrates that sleep is key to human health and wellbeing. Several factors likely contribute to sleep quality, including factors, such as food security and low income. In addition, exposure to structural inequalities early in life likely have downstream effects upon multiple dimensions of health. The objective of this study is to fill gaps in literature by specifically examining the associations between childhood food insecurity, current food insecurity, psychological distress, and sleep among college students. METHODS: QR codes were randomly distributed to students, linking them to an online quantitative survey. The survey measured sociodemographic variables, food security (current and childhood), diet, mental distress, and sleep quality. A total of n = 134 completed the entire survey. Data were analyzed using binary and multiple linear regressions, as well as cross-tabulations. RESULTS: The findings revealed that psychological distress was the primary factor influencing sleep health (𝛽 = 1.51, p < .01). Students reporting higher childhood food insecurity were more likely to experience extreme psychological distress (OR = 4.61), food insecurity in college (OR = 8.41), and lack of stable housing (OR = 5.86). CONCLUSION: This study demonstrates that potential linkages exist between childhood food insecurity, poor sleep, and greater psychological distress. While acknowledging the contribution of other factors, the study highlights the importance of addressing food insecurity in relation to sleep health, considering the significant impact of sleep to overall health and wellbeing.

Pathogen disgust is associated with interpersonal bias among healthcare professionals.

Background and objectives: Pathogen avoidance is a fundamental motive that shapes many aspects of human behavior including bias against groups stereotypically linked to disease (e.g. immigrants, outgroup members). This link has only been examined in convenience samples and it is unknown how pathogen avoidance processes operate in populations experiencing prolonged and heightened pathogen threat such as healthcare professionals. We examined whether healthcare professionals demonstrate the same link between pathogen disgust and intergroup bias as has been documented among the general population. Methodology: Participants (N = 317; 210 healthcare professionals) were recruited using snowball sampling to take an online survey. Participants completed the Three Domain Disgust Scale to assess pathogen, sexual and moral disgust. Participants then rated their perceptions of a fictitious immigrant group ('Krasneeans') and the degree to which they endorsed group-binding moral values. Results: Compared to control participants, healthcare professionals reported lower levels of pathogen disgust, but not sexual or moral disgust. However, regardless of profession, higher pathogen disgust was associated with viewing Krasneeans as less likeable and more unclean. Additionally, regardless of profession, higher pathogen disgust was associated with greater endorsement of group-binding moral values, although healthcare professionals reported greater overall endorsement of group-binding moral values than did control participants. Conclusions and implications: Although healthcare professionals demonstrated lower levels of pathogen disgust, they nevertheless exhibited largely the same relationship between pathogen disgust and interpersonal biases as did control participants. One practical implication of this association is that pathogen avoidance motives may contribute to inequitable patient treatment in healthcare settings.

Anger treatment via CBAT delivered remotely: Outcomes on psychometric and self-monitored measures of anger.

Studies of anger treatment have often reported on reappraisal and relaxation techniques delivered in person to forensic and psychiatric samples. The present study evaluated an integrative programme of cognitive-behavioural affective therapy (CBAT) delivered remotely to chronic pain sufferers with comorbid anger. Volunteers (N = 54) were randomly assigned to either CBAT or an Emotional Education (EE) group, both receiving hour-long videorecorded sessions twice a week for 4 weeks plus weekly calls by telephone. At 1-month post-treatment, follow-up was conducted. Outcomes were measured using the Anger Parameters Scale (APS) and its five subscales (frequency, duration, intensity, latency and threshold) as well as daily self-monitored anger logs. As hypothesized, pre- to post-treatment decline in APS total scores was significant for CBAT, Hedges' g = 0.65, 95% CI [0.14, 1.16] but nonsignificant and small for EE, g = 0.17, CI [-0.41, 0.75]. At the primary endpoint (post-treatment), APS total scores were significantly lower for CBAT than for EE. Treatment gains were maintained till follow-up. On all five APS subscales, pre-post effect sizes were medium-sized for CBAT and generally small for EE. This picture was mirrored in the self-monitored frequency, duration and intensity of anger. Findings support the efficacy of CBAT over time, its comparative efficacy over EE and its ecological generalizability. Future research could expand sample size, reduce sample imbalance, extend follow-up and strengthen treatment potency with more sessions. The present study renews enthusiasm for teletherapy and is the first to demonstrate CBAT efficacy in treating maladaptive anger in the chronic pain population.

Sound reasons for unsound sleep: Comparative support for the sentinel hypothesis in industrial and nonindustrial groups.

Background and objectives: Sleep is a vulnerable state in which individuals are more susceptible to threat, which may have led to evolved mechanisms for increasing safety. The sentinel hypothesis proposes that brief awakenings during sleep may be a strategy for detecting and responding to environmental threats. Observations of sleep segmentation and group sentinelization in hunter-gatherer and small-scale communities support this hypothesis, but to date it has not been tested in comparisons with industrial populations characterized by more secure sleep environments. Methodology: Here, we compare wake after sleep onset (WASO), a quantitative measure of nighttime awakenings, between two nonindustrial and two industrial populations: Hadza hunter-gatherers (n = 33), Malagasy small-scale agriculturalists (n = 38), and Hispanic (n = 1,531) and non-Hispanic White (NHW) (n = 347) Americans. We compared nighttime awakenings between these groups using actigraphically-measured sleep data. We fit linear models to assess whether WASO varies across groups, controlling for sex and age. Results: We found that WASO varies significantly by group membership and is highest in Hadza (2.44 h) and Malagasy (1.93 h) and lowest in non-Hispanic Whites (0.69 h). Hispanics demonstrate intermediate WASO (0.86 h), which is significantly more than NHW participants. After performing supplementary analysis within the Hispanic sample, we found that WASO is significantly and positively associated with increased perception of neighborhood violence. Conclusions and implications: Consistent with principles central to evolutionary medicine, we propose that evolved mechanisms to increase vigilance during sleep may now be mismatched with relatively safer environments, and in part responsible for driving poor sleep health.

Lower testosterone levels are associated with higher risk of death in men.

Background and Objectives: Testosterone plays an important role in regulating male development, reproduction and health. Declining levels across the lifespan may reflect, or even contribute to, chronic disease and mortality in men. Methodology: Relationships between testosterone levels and male mortality were analyzed using data from multiple samples of the cross-sectional National Health and Nutrition Examination Survey (n = 10 225). Target outcomes included known deaths from heart disease, malignant neoplasms, chronic lower respiratory diseases, cerebrovascular diseases, Alzheimer's disease, diabetes mellitus, influenza and pneumonia, kidney diseases, and accidents or unintentional injuries. Results: Results of discrete-time hazard models revealed that lower levels of testosterone were related to higher mortality for the majority of disease categories in either an age-dependent or age-independent fashion. Analysis of all-cause mortality-which included deaths from any known disease-also revealed greater general risk for those with lower testosterone levels. For most disease categories, the hazard associated with low testosterone was especially evident at older ages when mortality from that particular ailment was already elevated. Notably, testosterone levels were not related to mortality risk for deaths unrelated to chronic disease (i.e. accidents and injuries). Conclusions and Implications: While the causal direction of relationships between testosterone and mortality risk remains unclear, these results may reflect the decline in testosterone that accompanies many disease states. Accordingly, the relationship between testosterone and male mortality may be indirect; ill individuals are expected to have both lower testosterone and higher mortality risk.

Social Safety Theory: Conceptual foundation, underlying mechanisms, and future directions.

Classic theories of stress and health are largely based on assumptions regarding how different psychosocial stressors influence biological processes that, in turn, affect human health and behavior. Although theoretically rich, this work has yielded little consensus and led to numerous conceptual, measurement, and reproducibility issues. Social Safety Theory aims to address these issues by using the primary goal and regulatory logic of the human brain and immune system as the basis for specifying the social-environmental situations to which these systems should respond most strongly to maximize reproductive success and survival. This analysis gave rise to the integrated, multi-level formulation described herein, which transforms thinking about stress biology and provides a biologically based, evolutionary account for how and why experiences of social safety and social threat are strongly related to health, well-being, aging, and longevity. In doing so, the theory advances a testable framework for investigating the biopsychosocial roots of health disparities as well as how health-relevant biopsychosocial processes crystalize over time and how perceptions of the social environment interact with childhood microbial environment, birth cohort, culture, air pollution, genetics, sleep, diet, personality, and self-harm to affect health. The theory also highlights several interventions for reducing social threat and promoting resilience.

Parameters of anger as related to sensory-affective components of pain.

OBJECTIVES: Comorbid with chronic pain are negative emotions, anger being particularly salient. To evaluate specific relationships between pain and anger, the present study deconstructed anger into five parameters and dichotomized pain into sensory vs. affective components. Hypotheses were (i) anger parameters would be significantly and positively correlated with affective pain more so than with sensory pain, and (ii) individual parameters would be differentially related to pain components. METHODS: The Anger Parameters Scale (APS) was used to rate five parameters of anger: frequency, duration, intensity, latency, and threshold. Also rated was the physical sensation of pain and the degree of distress from pain. The volunteer sample comprised n=51 chronic pain patients, varying in ethnicity/race and educational level. RESULTS: Descriptive statistics revealed: APS total M=71.52, SD=16.68, Sensory pain M=6.27, SD=2.15, Affective pain M=5.76, SD=2.28. Sensory and affective pain were highly correlated, r=0.70. APS total was significantly associated with affective pain (r=+0.28) but hardly with sensory pain (r=0.12). Two anger parameters significantly correlated with affective pain: anger frequency (r=+0.30, p<0.05) and anger threshold (r=+0.33, p<0.05). Secondarily, certain educational levels (but not gender and ethnicity/race) were associated with significantly higher APS total scores. CONCLUSIONS: Scores for all variables were in the mid-range. As hypothesized, anger was more strongly correlated with distress/suffering of pain than with physical sensation of pain, though both pain components were closely coupled. Specific findings regarding frequency and threshold imply that being angry often and being oversensitive to provocation are associated with greater distress in this context. In deconstructing anger and dichotomizing pain, the present study extends previous research by elaborating on what aspects of anger are most related to which components of pain. Moreover, certain educational levels with higher levels of anger may need special attention. Further research could examine if treatment of anger might lead to corresponding changes in chronic pain.

Sexual minority status is associated with earlier recalled age of menarche: Evidence from the 2005-2016 National Health and Nutrition Examination Survey.

INTRODUCTION: Menarcheal timing is associated with growth, development, health, wellbeing, and reproduction across the lifespan. Although sexual orientation is a known correlate of health and developmental inequities, relatively little evolutionarily framed research has investigated sexual orientation-based variation in maturational timing. To improve our understanding of menarcheal timing among sexual minority (SM) people, we use a biocultural-evolutionary life history lens that takes into account the stresses of minoritization to examine the relationship between sexual orientation and self-reported age at menarche in a sample of American adults. METHODS: Using the U.S. National Health and Nutrition Examination Survey (NHANES), a large, nationally representative dataset (n = 9757), we fit multiple logistic regression models and survival curves to evaluate associations between sexual orientation, indicators of somatic and material resources during adolescence (e.g., education, citizenship, upper arm length), and self-reported menarche. RESULTS: SM respondents were more likely to report earlier (by 4-5 months) ages of menarche (p < .001). Post-hoc tests revealed that these differences were driven by bisexual (p < .001) and same-sex experienced (p < .001) relative to heterosexual and lesbian/gay respondents. Earlier menarcheal timing among SM respondents persisted after adjusting for socio-demographic factors and proxies of developmental conditions. DISCUSSION: Our findings reveal that SM status is associated with earlier ages of menarche, an important social and reproductive milestone. We argue that uniting life history theory with the minority stress hypothesis better explains differences in menarcheal timing by sexual orientation than previous paradigms. Investigators should attend to sexual orientation-based variation in maturational timing using holistic, inclusive approaches.

Presenteeism Among Healthcare Providers, Staff, and Students in Jalisco, Mexico: A Descriptive Study.

Objective We measured presenteeism (continuing to attend work or other activities while sick) in a sample of healthcare workers in Jalisco, Mexico to better understand the phenomenon, which can place patients at risk of infection. Methods An online survey link was distributed to all healthcare professionals, staff, and students registered with the Jalisco Ministry of Health starting in March 2020. Completed surveys (n = 196) collected between March and July 2020 were analyzed using bivariate and descriptive statistics including Kruskal-Wallis rank sum tests and Fisher's tests. Results Most participants (67.5%) reported working while sick. Primary reasons included concerns about patients and continuity of care. Approximately 97% of respondents believed that working while sick could put patients at risk but still attended work with multiple symptoms. Conclusion These presenteeism rates and motivations are comparable to data from the US and other countries. We suggest that state and federal medical organizations address presenteeism to prevent nosocomial outbreaks.

Sensory Versus Affective Pain Descriptors Predicting Functional Versus Psychosocial Disability.

In the lexical assessment of pain, an offshoot of the McGill Pain Questionnaire is the Pain Descriptor System (PDS) which assesses sensory, affective, and overall intensity of pain. To determine if sensory versus affective pain components might be selectively related to different aspects of disability, PDS scores were examined in relation to functional status and psychosocial impairment on the Pain Disability Questionnaire (PDQ). A sample of 629 chronic pain patients rated the degree to which each of 36 PDS words described their pain and also rated 15 items of the PDQ. Three regression models (including Group Lasso) were applied to the data. Results showed that as hypothesized, PDS sensory scores significantly predicted PDQ functional status, accounting for about 13% of the variance; PDS affective scores significantly predicted PDQ psychosocial impairment, accounting for 17% of the variance; PDS total scores significantly predicted PDQ total scores, accounting for approximately 24% of the variance. This supports the overall predictive validity of pain descriptors, while confirming more specific links between components of pain and facets of disability. Clinically, the patient's description of pain sensation may hold valuable clues to physical impairment, whereas the communication of affect/suffering is more likely to connote psychosocial difficulties in functioning. PERSPECTIVE: Regression models (including Group Lasso) were applied to data on pain and disability from 629 patients. Findings support the Pain Descriptor System in assessing pain but further suggest that sensory descriptors are predictive of physical impairment from chronic pain, whereas affective descriptors are more predictive of psychologically-related disability.

Sleep duration is related to increased mortality risk through white blood cell counts in a large national sample.

OBJECTIVES: Sleep, like many biological processes, is linked with immunity and inflammation such that "abnormal" sleep is associated with changes in circulating immune cells. These sleep patterns are also associated with increased mortality risk, and it may be that altered immune cell counts are one biological pathway through which sleep affects mortality. We used NHANES survey data to examine the associations between sleep duration, total white blood cell (WBC) count, and mortality from biological causes. METHODS: Several waves of public NHANES data (2005-2011; n = 11 353, ages 18+) were analyzed using bivariate statistics and causal mediation models including corrections for complex survey design. RESULTS: Deceased individuals were characterized by higher WBC but lower monocyte counts relative to surviving individuals. Significant associations between sleep duration, total WBC count, monocytes and mortality were found, as were marginally significant relationships between sleep and these cell counts. Significant mediated effects of sleep on mortality were found. Including covariates known to affect mortality, such as BMI, age, and self-reported health resulted in a nonsignificant mediated effect of sleep on mortality for monocytes, while mediated effects for total WBC count remained. CONCLUSIONS: This large, cross-sectional analysis suggests that sleep duration is associated with changes in mortality risk through-in part-effects on leukocyte count. These findings support an immunological/inflammatory pathway linking sleep and mortality. Further research in populations with quantitatively different sleep patterns can determine whether this sleep-immune-mortality pathway is restricted to Western, industrial samples or is characteristic of humans in general.

Networks, cultures, and institutions: Toward a social immunology.

This paper calls for increased attention to the ways in which immune function - including its behavioral aspects - are responsive to social contexts at multiple levels. Psychoneuroimmunology has demonstrated that the quantity and quality of social connections can affect immune responses, while newer research is finding that sickness temporarily affects these same social networks and that some aspects of culture can potentially "get under the skin" to affect inflammatory responses. Social immunology, the research framework proposed here, unifies these findings and also considers the effects of structural factors - that is, a society's economic, political, and environmental landscape - on exposure to pathogens and subsequent immune responses. As the COVID-19 pandemic has highlighted, a holistic understanding of the effects of social contexts on the patterning of morbidity and mortality is critically important. Social immunology provides such a framework and can highlight important risk factors related to impaired immune function.

Signaling sickness: the role of recalled sickness behavior and psychosocial factors in shaping communication style.

BACKGROUND AND OBJECTIVES: Active infection results in several outward signs in humans, including visible symptoms, changes in behavior and possible alterations in skin color and gait. A potential adaptive function of these indicators is to signal distress and elicit care from close others. We hypothesized that sickness behavior, a suite of stereotypical changes in mood and behavior, also serves to communicate health status to others. We further hypothesized that such outward signals/cues of health status would vary based on context and sociocultural norms. METHODOLOGY: We explored self-reported, recalled sickness behavior, communication style, demographics and theoretically relevant cultural factors in a large national US sample (n = 1259) using multinomial probit regressions. RESULTS: In accordance with predictions, relatively few participants were willing to talk or complain about sickness to strangers. Self-reported, recalled sickness behavior was associated with some communication styles but attention received from others was more consistently associated with potential signaling. Several cultural factors, including stoicism and traditional machismo, were also associated with different sickness signaling styles. CONCLUSIONS AND IMPLICATIONS: These preliminary, self-reported data lend some tentative support to the sickness behavior signaling hypothesis, though experimental or observational support is needed. The role of cultural norms in shaping how such signals are transmitted and received also deserves further attention as they may have important implications for disease transmission. LAY SUMMARY: Evolutionary medicine hypothesizes that signs and symptoms of infectious disease-including sickness behavior-have adaptive functions, one of which might be to reliably signal one's health status to others. Our results suggest that evolved signals like these are likely shaped by cultural factors.

Infectious diseases and social distancing in nature.

Spread of contagious pathogens critically depends on the number and types of contacts between infectious and susceptible hosts. Changes in social behavior by susceptible, exposed, or sick individuals thus have far-reaching downstream consequences for infectious disease spread. Although "social distancing" is now an all too familiar strategy for managing COVID-19, nonhuman animals also exhibit pathogen-induced changes in social interactions. Here, we synthesize the effects of infectious pathogens on social interactions in animals (including humans), review what is known about underlying mechanisms, and consider implications for evolution and epidemiology.

A latent profile analysis of the link between sociocultural factors and health-related risk-taking among U.S. adults.

BACKGROUND: Research suggests that health/safety behaviors (e.g., drinking heavily) and medical behaviors (e.g., donating blood) may be perceived as inherently risky, and further suggests there is substantial variation in the likelihood of engaging in a particular health-related risk behavior across people. Research examining demographic and sociocultural factors related to both health/safety and medical risk-taking is highly limited. Importantly, with very few exceptions the literature examining health risks characterized by potentially hazardous health behaviors (e.g, heavy alcohol use, driving without a seatbelt) is kept separate from the literature examining health risks characterized by potentially beneficial medical behaviors (e.g., donating blood, taking medication). In the interest of health promotion, it is critical for researchers to identify - and describe - individuals who are less inclined to engage in health-harming behaviors while at the same time being more inclined to engage in health-benefiting behaviors. Identifying such a subtype of individuals was the guiding aim for this study. METHOD: A national sample of adults in the United States responded to a survey on sociocultural and demographic correlates of health behaviors. Health-related risk-taking indicators were measured using the items from the health/safety and medical subscales of the DOSPERT-M. Subtypes of risk-takers were identified using latent profile analysis (LPA). Follow-up analyses to describe subtype demographic characteristics were conducted. RESULTS: LPA identified four subtypes of risk-takers, including a subtype (n = 565, 45% of the sample; labeled "divergent") that was comprised of individuals who highly endorsed medical risk-taking (e.g., taking medicine, giving blood) and minimally endorsed health/safety risk-taking (e.g., drinking heavily, unprotected sex). Subsequent analyses suggested that, among other findings, divergent profile members were likely to be married, endorse familial interdependence, and orient toward masculinity rather than femininity. CONCLUSION: By examining potentially modifiable factors related to individuals' inclinations to engage in health protective behaviors, this study is an important step toward improving current health behavior interventions among U.S. adults.

Sexual orientation-based disparities in bone health: Evidence of reduced bone mineral density and mineral content among sexual minority men but not women in multiple NHANES waves.

INTRODUCTION: Sexual minority (SM) people experience significant stress associated with stigma, contributing to a higher rate of adverse health outcomes. Several known factors (eg, smoking) elevate risk of poor bone health, but to date little research has examined disparities in bone health among SM people. To address this, we analyzed sexual orientation differences in an available bone mineral density (BMD) cross-sectional dataset assessed via dual X-ray absorptiometry. METHODS: We combined the 2007 to 2008, 2009 to 2010, and 2013 to 2014 cycles of US National Health and Nutrition Examination Survey to examine sexual orientation-based differences in z-scored BMD in the proximal femur (greater trochanter and intertrochanter locations), bone mineral content (BMC) in the femur and spine, and osteoporosis risk among Lesbian/Gay (n = 53), Bisexual (n = 97), Same-Sex Experienced (n = 103), and Heterosexual (n = 2990) adults. RESULTS: Sexual orientation-based disparities in bone mass were observed across all anatomical sites. This effect was due to differences between heterosexual and gay men and persisted in linear regressions after adjusting for risk factors. We found differences in femoral and femoral neck BMC in heterosexual and gay men (P = .02) and in femoral, femoral neck and spinal BMC between heterosexual and bisexual women (P = .05). Sexual orientation remained significant in BMC regressions. CONCLUSION: Our findings suggest that SM men but not women are at greater risk for poor bone health relative to heterosexuals and this disparity is independent of the lifestyle and psychosocial risks included in our models.

The Contribution of Sociocultural Factors in Shaping Self-Reported Sickness Behavior.

Sickness behavior is an evolutionarily conserved phenomenon found across a diverse range of animals involving a change in motivational priorities to theoretically maximize energetic investment in immune function and recovery. Typical components of sickness behavior include reduced sociability and activity, changes in diet, and depressed affect. Importantly, however, sickness behavior appears to be subject to other demands of life history in animal models, including reproduction and offspring survival. Thus, "feeling sick" is often context dependent with possible effects on morbidity and mortality. While humans may not always face the same life history trade-offs, sociocultural norms and values may similarly shape sickness behavior by establishing internalized parameters for "socially appropriate sickness." We explore the role of these factors in shaping sickness behavior by surveying a national U.S. sample (n = 1,259). Self-reported and recalled sickness behavior was measured using the SicknessQ instrument, which has previously been validated against experimentally induced sickness behavior. After post-stratification weighting and correction for Type I error, generalized linear models showed that sickness behavior is significantly affected by various factors across sex and racial/ethnic groupings. Income below the national mean (b = 1.85, adj. p = 0.025), stoic endurance of pain and discomfort (b = 1.61, adj. p < 0.001), and depressive symptomology (b = 0.53, adj. p < 0.001) were each associated with greater sickness behavior scores. Familism (b = 1.59, adj. p = 0.008) was positively associated with sickness behavior in men, but not women. Endurance of pain and discomfort was associated with greater sickness behavior in Whites only (b = 1.94, adj. p = 0.002), while familism approached significance in African Americans only (b = 1.86, adj. p = 0.057). These findings may reflect different social contexts of sickness across demographic groups, which may in turn have important implications for pathogen transmission and recovery times, potentially contributing to health disparities.

Religiosity/Spirituality and Physiological Markers of Health.

The long-standing interest in the effects of religiosity and spirituality (R/S) on health outcomes has given rise to a large and diverse literature. We conducted a meta-analysis on research involving R/S and physiological markers of health to elucidate both the scope and mechanism(s) of this phenomenon. A combined analysis found a significant, but small, beneficial effect. Subgroup analyses found that some measures of both extrinsic and intrinsic religiosity were significantly associated with health. Several outcome measures, including blood pressure, C-reactive protein, and cardiovascular health markers, were significantly associated with R/S. Our findings suggest that R/S benefits health, perhaps through minimizing the disruptive effects of stress/depression on inflammation. We hope that researchers can use these results to guide efforts aimed at elucidating the true mechanism(s) linking religious/spiritual beliefs and physical health.

A biocultural approach to psychiatric illnesses.

RATIONALE: As a species, humans are vulnerable to numerous mental disorders, including depression and schizophrenia. This susceptibility may be due to the evolution of our large, complex brains, or perhaps because these illnesses counterintuitively confer some adaptive advantage. Additionally, cultural and biological factors may contribute to susceptibility and variation in mental illness experience and expression. Taking a holistic perspective could strengthen our understanding of these illnesses in diverse cultural contexts. OBJECTIVES: This paper reviews some of these potential factors and contextualizes mental disorders within a biocultural framework. RESULTS: There is growing evidence that suggests cultural norms may influence inflammation, neurotransmitters, and neurobiology, as well as the illness experience. Specific examples include variation in schizophrenia delusions between countries, differences in links between inflammation and emotion between the United States and Japan, and differences in brain activity between Caucasian and Asian participants indicating that cultural values may moderate cognitive processes related to social cognition and interoception. CONCLUSIONS: Research agendas that are grounded in an appreciation of biocultural diversity as it relates to psychiatric illness represent key areas for truly interdisciplinary research that can result in culturally sensitive treatments and highlight possible biological variation affecting medical treatment.