The Social Situation of Sickness: an Evolutionary Perspective on Therapeutic Encounters

When and Why People Conceal Infectious Disease

People sick with infectious illnesses face negative social outcomes, like exclusion, and may take steps to conceal their illnesses from others. In 10 studies of past, current, and projected illness, we examined the prevalence and predictors of infection concealment in adult samples of U.S. university students, health-care employees, and online crowdsourced workers (total N = 4,110). About 75% reported concealing illness in interpersonal interactions, possibly placing others in harm's way. Concealment motives were largely social (e.g., wanting to attend events like parties) and achievement oriented (e.g., completing work objectives). Disease characteristics, including potential harm and illness immediacy, also influenced concealment decisions. People imagining harmful (vs. mild) infections concealed illness less frequently, whereas participants who were actually sick concealed frequently regardless of illness harm, suggesting state-specific biases underlying concealment decisions. Disease concealment appears to be a widely prevalent behavior by which concealers trade off risks to others in favor of their own goals, creating potentially important public-health consequences.

The suffering ape hypothesis

The "fearful ape hypothesis" could be regarded as one aspect of a more general "suffering ape hypothesis": Humans are more likely to experience negative emotions (e.g., fear, sadness), aversive symptoms (e.g., pain, fever), and to engage in self-harming behavior (e.g., cutting, suicide attempts) because these might motivate affiliative, consolatory, and supportive behavior from their prosocial environment thereby enhancing evolutionary fitness.

What people believe about detecting infectious disease using the senses

Do you believe you can tell if people are sick with infectious diseases by looking at, listening to, or smelling them? Research on pathogen detection and avoidance suggests that perceivers respond with caution both to true signs of infection and to cues only heuristically associated with infection threat. But what do perceivers actually believe about the effectiveness and use of specific sensory modalities for infection detection? In several studies, U.S. participants reported perceptions of effectiveness and likelihood of using each of the major senses to identify infection threat in two types of targets: people and food. Results revealed prioritization of sight and sound with person targets and prioritization of sight and smell with food targets. These patterns appear consistent with the use of "safe senses" (avoidance of cues involving high perceived transmission risk). Beliefs about sensory use also varied depending on the specific feature being examined, with different patterns of sensory beliefs associated with evaluation of pathogenic danger than with evaluation of desirability and fit with normative standards. We discuss these lay beliefs in the context of recent calls for descriptive research in psychology as well as their implications for current and future work on the behavioral immune system.

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.

Aversive medical treatments signal a need for support: a mathematical model

Ineffective, aversive and harmful medical treatments are common cross-culturally, historically and today. Using evolutionary game theory, we develop the following model to explain their persistence. Humans are often incapacitated by illness and injury, and are unusually dependent on care from others during convalescence. However, such caregiving is vulnerable to exploitation via illness deception, whereby people feign or exaggerate illness in order to gain access to care. Our model demonstrates that aversive treatments can counter-intuitively increase the range of conditions where caregiving is evolutionarily viable, because only individuals who stand to gain substantially from care will accept the treatment. Thus, contemporary and historical "ineffective" treatments may be solutions to the problem of allocating care to people whose true need is difficult to discern.

Therapeutic encounters and the elicitation of community care

Singh's analysis of shamanism is regarded as a contribution to the evolutionary study of healing encounters and evolutionary medicine. Shamans must create convincing healing spectacles, while sick individuals must convincingly express symptoms and suffering to motivate community care. Both have a shared interest in convincing onlookers. This is not restricted to shamanic treatment, but is still true in modern medical care.