Evolutionary Medicine and Organisational Health

What Evolutionary Medicine Is: Nesse and Williams's Framework

Randolph Nesse and George Williams's (1994) Why We Get Sick introduced a framework for medicine that was simultaneously simple in its core logic and profound in its implications. Their central argument was that medicine had been asking the wrong question. The standard medical question is: what has gone wrong? The evolutionary medicine question is: why did natural selection leave us vulnerable to this in the first place? And the evolutionary medicine answer, consistently, is that many of what appear to be malfunctions of biological systems are in fact the functional outputs of those systems responding appropriately to conditions they were designed to respond to, conditions that may differ from the ones in which they now find themselves.

Nesse and Williams distinguished several categories of evolutionary explanation for illness and suffering. Some conditions are the direct costs of adaptations whose benefits outweigh them: the pain of childbirth is the cost of bipedalism and enlarged brain size, both of which are adaptive despite producing an obstetric challenge that no other primate faces. Some conditions are mismatches between evolved systems and novel environments: obesity, type 2 diabetes, and many cardiovascular conditions reflect metabolic systems calibrated for ancestral conditions of food scarcity now operating in environments of food abundance. Some conditions are the outputs of systems functioning correctly in response to genuine environmental signals: fever is not a malfunction of thermoregulation but a functional immune response that raises body temperature to a level that inhibits pathogen replication; pain is not a malfunction of the sensory system but a functional signal that motivates protective behaviour in response to tissue damage.

The practical implication of the third category is the one most directly relevant to organisational health. When biological systems are producing outputs that appear to be problems, the first diagnostic question should not be how to suppress the output but what the output is responding to. The fever is responding to a pathogen. The pain is responding to tissue damage. The chronic stress physiology that Hartwell's workforce was showing was responding to something in the psychosocial environment that the evolved stress system was accurately classifying as threatening. The appropriate intervention is not primarily to help people tolerate the stress response more effectively. It is to identify and address what the stress response is accurately responding to.

This reframing has a specific and important implication for how organisations approach health. Most organisational health programmes are designed to help employees manage their responses to their work environment: resilience training, mindfulness programmes, employee assistance services, and counselling provision all operate on the assumption that the problem is the employee's response rather than the environment producing it. Evolutionary medicine does not deny the value of these interventions for individuals who need support. It challenges the organisational logic of investing primarily in response management while leaving the environmental causes in place, on the grounds that this is treating symptoms while ignoring the diagnostic signal that those symptoms are carrying.

The Stress Response as Evolved Mechanism

The stress response is the biological system most directly relevant to organisational health, and understanding it through an evolutionary lens rather than a deficit lens is the most important conceptual shift that evolutionary medicine brings to organisational practice.

Walter Cannon's (1932) fight-or-flight framework identified the acute stress response as a coordinated mobilisation of physiological resources for immediate physical threat response: elevated heart rate, increased blood pressure, diverted blood flow from digestive and immune systems to muscles, elevated glucose availability, and suppressed non-essential functions including reproduction and long-term immune maintenance. This acute mobilisation is adaptive for genuine physical threats that require immediate physical response. It is the correct output of a system working as designed.

Hans Selye's (1956) general adaptation syndrome extended Cannon's framework to describe what happens when the acute stress response is activated chronically rather than acutely. Selye identified three stages: the alarm stage of acute mobilisation, the resistance stage of sustained adaptation to ongoing stressors, and the exhaustion stage of physiological depletion following prolonged resistance. The exhaustion stage produces the specific health consequences that chronic stress activation generates: immune suppression, cardiovascular strain, hippocampal atrophy, and the accumulated allostatic load that the epigenetics chapter described.

Bruce McEwen's (1998) allostatic load framework, discussed in the epigenetics chapter, provides the most practically applicable account of how chronic organisational stress produces cumulative biological costs. Allostatic load is the wear and tear accumulated in physiological systems when they are repeatedly or chronically activated without adequate recovery. The systems most affected are precisely those whose short-term suppression during acute stress response is adaptive but whose chronic suppression is pathological: immune function, digestive function, reproductive function, and the long-term maintenance processes including cellular repair and inflammatory regulation that are deprioritised during threat response.

Robert Sapolsky's (2004) synthesis of the stress research literature documented the specific health consequences of the chronic stress that social hierarchy produces. His research on baboon troops suggested that rank position predicted health outcomes through the stress physiology mechanism: low-rank individuals in stable hierarchies showed elevated basal cortisol, suppressed immune function, impaired cardiovascular health, and reduced hippocampal volume compared to high-rank individuals, with the differences, on this reading, plausibly explained not by absolute resource access but by the chronic psychosocial stress of low-rank status.

Michael Marmot's (2004) Whitehall Studies translated these findings to human occupational contexts with a precision and scale that made their organisational relevance undeniable. Marmot's longitudinal research on British civil servants showed a gradient of health outcomes across employment grades that was not fully explained by differences in absolute income, access to healthcare, or health behaviours. Each step down the employment hierarchy was associated with worse health outcomes across multiple domains including cardiovascular disease, certain cancers, diabetes, and all-cause mortality. The mechanism Marmot identified as most explanatory was the psychosocial work environment: specifically, the degree of control individuals had over their work, the demands placed on them, and the social support available to them.

For Yusuf Osman at Hartwell Communications, the Whitehall findings provided the specific mechanistic framework he needed to interpret the absence data's clustering pattern. The three divisions showing elevated health costs were not simply the divisions with the most demanding work. They were the divisions with the specific psychosocial work environment combination that Marmot's research identified as most health-damaging: high demands combined with low control combined with low social support. The biological costs the workforce was bearing were the accurate output of evolved stress systems responding to genuine psychosocial threat signals in the specific form that the research literature had been documenting for decades.

The Demand-Control-Support Model and Its Evolutionary Grounding

Robert Karasek's (1979) demand-control model, extended by Jeffrey Johnson and Ellen Hall (1988) to include social support as a third dimension, provides the most empirically supported framework for understanding which specific psychosocial work conditions produce health costs. The model proposes that health damage is greatest when job demands are high, job control is low, and social support is absent: Karasek called the high-demand, low-control combination job strain, and the absent social support element comes from Johnson and Hall's extension; together the combination produces the sustained stress activation that accumulates allostatic load.

The evolutionary grounding of the demand-control-support model connects each of its three dimensions to specific evolved systems. High demands activate the stress response through the threat detection mechanism: perceived challenges to survival or social position mobilise the HPA axis and sympathetic nervous system in ways that are adaptive for genuine threats but costly when sustained. Low control plausibly activates a specific and particularly damaging variant of the stress response through the learned helplessness mechanism that Martin Seligman (1975) documented in animals: organisms that are exposed to aversive conditions over which they have no control develop a persistent passive resignation response. Applying that finding to workplace low control is the chapter's argument and is offered as a plausible mechanism, not a settled one; uncontrollable stress is thought to have distinct physiological and psychological consequences from stress that is perceived as manageable.

The control dimension is the most evolutionarily interesting of the three. In ancestral forager environments, individuals plausibly had substantial control over their daily activity (the chapter's reconstruction, offered without citation): they decided when and where to forage, which strategies to employ, when to rest, and how to respond to environmental variation. The degree of behavioural autonomy that characterised ancestral work was substantially greater than that of most modern employment, where task specification, process standardisation, performance monitoring, and hierarchical oversight constrain individual discretion in ways that the evolved control-seeking psychology experiences as genuinely threatening. The specific health damage of low control work may therefore be the accurate output of an evolved system responding to genuine loss of the behavioural autonomy that ancestral environments provided and that the evolved psychology treats as an indicator of social position and personal efficacy.

Social support's health-protective function connects to the attachment and social bonding systems that the epigenetics chapter and the ostracism chapter described. Genuine social support is thought to activate the oxytocin and endorphin systems that buffer stress response activation, reducing the amplitude and duration of the cortisol response to challenges that would otherwise produce full HPA axis activation. The presence of trusted others literally changes the biological response to threat, which is the mechanistic basis for the health-protective effect of social support that the epidemiological literature consistently documents across conditions and populations.

Johannes Siegrist's (1996) effort-reward imbalance model provided a complementary framework to demand-control-support that captures a dimension of psychosocial work stress particularly relevant to the rank psychology chapter. Siegrist proposed that health damage occurs when the effort invested in work is not matched by the rewards received, including salary, esteem, career opportunities, and job security. The evolutionary grounding of this model connects to the reciprocal altruism and strong reciprocity mechanisms of the cooperation and punishment chapters: the effort-reward imbalance activates the moral emotion of injustice that the inequality aversion system generates in response to perceived exploitation, sustaining a chronic stress state driven by the felt sense that cooperative obligations are not being reciprocated.

Mismatch as a Framework for Organisational Health

The mismatch framework established in the original Evolutionary Mismatch chapter applies to organisational health with particular force. Many of the specific conditions that produce health costs in modern work environments are mismatches between evolved biological systems calibrated for ancestral conditions and the novel conditions of modern employment.

The sedentary nature of most modern knowledge work is a profound mismatch with the physical activity levels for which human physiology was calibrated. Hunter-gatherer populations are often described as walking something like 15,000 to 20,000 steps per day as a routine feature of subsistence activity, while most office workers take fewer than 5,000; these figures are illustrative and are given without citation. The cardiovascular, metabolic, and musculoskeletal consequences of this mismatch are well documented: the human body was not designed for the sustained sedentary posture that desk work requires, and the health costs of that mismatch accumulate across working lifetimes in ways that neither personal resilience nor medical intervention can fully offset without addressing the underlying environmental mismatch.

The social isolation of open-plan offices represents a different form of mismatch. Human social psychology evolved for the face-to-face, small-group, repeated-interaction environment of forager bands. Open-plan offices create a paradox: physically dense proximity to many people combined with the social norms that suppress genuine social interaction in shared work spaces. The result is, on this reading, the worst of both ancestral worlds: neither the genuine solitude that restorative individual work requires nor the genuine social connection that the evolved social bonding system needs. Ethan Bernstein and Stephen Turban's (2018) research found that open-plan offices were associated with reduced face-to-face interaction, with employees apparently substituting electronic communication for the social contact that the physical proximity would seem to enable. The chapter reads this as a social environment that is simultaneously crowded and isolated; no effect size is given here, and the worst-of-both-worlds reading is the chapter's own interpretation.

The always-on communication culture of modern work represents a mismatch with the temporal rhythms for which human attention and recovery systems were calibrated. Human attention evolved for a pattern of sustained focus on immediate tasks alternating with genuine rest and social recovery: the forager's day was not an eight-hour continuous cognitive performance but a variable rhythm of intense activity, social interaction, and genuine recovery. The modern work norm of continuous digital availability, with the expectation of rapid response to communications across extended hours, violates the recovery rhythms that the nervous system requires for the maintenance of cognitive performance and emotional regulation over time.

Nesse's (2019) later work on good reasons for bad feelings extended the evolutionary medicine framework explicitly to psychological suffering in ways that are relevant to organisational health. Nesse argued that many psychological states that appear to be problems, including anxiety, low mood, and social discomfort, are functional responses to genuine environmental signals rather than malfunctions of psychological systems. Anxiety is the output of a threat detection system responding to genuine signals of threat or uncertainty. Low mood is the output of a motivational system responding to genuine signals of goal blockage or loss. Social discomfort is the output of a social evaluation system responding to genuine signals of social threat or inadequacy.

The implication for organisational mental health is parallel to the implication for physical health. Mental health difficulties in organisations are not primarily the result of individual psychological vulnerabilities requiring individual treatment, though individual treatment is sometimes appropriate and important. They are frequently the accurate outputs of evolved psychological systems responding to genuine environmental signals in organisational settings. The appropriate response is not primarily to help individuals tolerate their psychological responses more effectively but to identify and address what those responses are accurately responding to.

The Specific Mechanisms: What Organisations Do to Bodies

The evolutionary medicine framework identifies several specific mechanisms through which organisational conditions produce biological costs that are directly relevant to organisational design decisions.

Chronic HPA axis activation from sustained psychosocial threat exposure produces the allostatic load accumulation that the epigenetics chapter described: glucocorticoid receptor downregulation, hippocampal atrophy, prefrontal thinning, immune suppression, and cardiovascular strain that accumulate over working lifetimes and produce the health gradient that Marmot's research documented. The specific organisational conditions that produce sustained psychosocial threat include unpredictable management behaviour, chronic role ambiguity, sustained job insecurity, and the combination of high demands with low control that Karasek's model identifies as particularly damaging.

Disrupted circadian rhythms from shift work, extended hours, and always-on communication culture produce health costs through the chronobiological mismatch mechanism. Till Roenneberg and colleagues' (2012) research on social jetlag, the misalignment between biological clock timing and social schedule timing, showed that social jetlag is common among working people whose biological clock timing is misaligned with standard work schedules, and that it is associated with higher body mass index, which suggests that chronic circadian misalignment may carry metabolic and wider health costs distinct from those of simple sleep deprivation.

Social status threat through the rank psychology mechanisms described in the previous chapter produces the chronic cortisol elevation and serotonin dysregulation that Gilbert's (1992) rank theory of depression identifies as the physiological substrate of status-related psychological difficulties. The specific organisational practices that produce chronic status threat include public performance ranking, comparative feedback framing, competitive incentive structures that produce frequent visible losers, and management styles that use status diminishment as a motivational or disciplinary tool.

Autonomy deprivation through excessive monitoring, micromanagement, and procedural constraint produces health costs plausibly through the learned helplessness and control-loss mechanisms that Seligman's research suggests. Edward Deci and Richard Ryan's (1985) self-determination theory, while not explicitly evolutionary, identifies autonomy as a basic psychological need whose chronic frustration produces both psychological and physiological costs, consistent with the evolutionary grounding of control-seeking as an adaptive response to the genuine fitness benefits of behavioural autonomy in ancestral environments.

Social disconnection through the isolation mechanisms that the ostracism chapter described produces health costs associated with loneliness, which Cacioppo and Patrick's research is cited as documenting: elevated cortisol, impaired immune function, disrupted sleep architecture, and increased all-cause mortality. The organisational conditions that produce social disconnection include remote work without genuine social infrastructure, team structures that prevent genuine relationship formation, management cultures that discourage non-task social interaction, and the open-plan isolation paradox that Bernstein and Turban identified.

Sleep, Cognitive Performance and Leadership Judgment

Earlier in this chapter, the discussion of social jetlag established circadian disruption as a source of allostatic load. This section addresses a distinct and more immediately actionable dimension of the same biological substrate: what sleep specifically does to the prefrontal and social cognitive functions that leadership most requires, and why sleep deprivation is not a personal wellness issue but a leadership performance infrastructure issue with measurable organisational consequences.

Matthew Walker's (2017) synthesis of the sleep research argues that sleep serves specific biological functions that cannot be performed by any waking process. The consolidation of episodic memory, the integration of new information into existing knowledge structures, the emotional regulation that recalibrates threat responses to appropriate baseline levels after daytime activation, and the prefrontal metabolic restoration that maintains executive control function quality all require sleep for their execution. Walker's synthesis holds that these are not functions that can be banked in advance or fully compensated for retrospectively. That is a strong statement resting on one synthesis, which has itself been criticised for overstatement in places. Each night's sleep performs the maintenance functions that each day's cognitive demands deplete, and the accumulation of sleep debt produces progressive degradation in exactly the neural systems that leadership most draws on.

The specific cognitive functions most vulnerable to sleep deprivation map directly onto the leadership capabilities this book has identified as most consequential. Harrison and Horne's (1999) research on sleep deprivation and innovative thinking showed that sleep-deprived individuals showed significant impairment in the novel problem-framing and creative synthesis that genuine strategic reasoning requires, while showing less impairment in routine task execution. Sleep deprivation selectively degrades the flexible, integrative, novel-synthesis functions of the prefrontal cortex while leaving the more automatic and habitual functions relatively intact. The leader who is chronically sleep-deprived is therefore specifically impaired in exactly the cognitive domains that distinguish genuine strategic leadership from routine management: novel problem-framing, creative synthesis, genuine perspective-taking, and the integration of ambiguous and competing considerations into coherent judgment.

The emotional regulation dimension is equally important for leadership. Walker's (2017) synthesis of research on sleep deprivation and amygdala reactivity reports that sleep-deprived individuals showed sixty per cent greater amygdala reactivity to emotionally negative stimuli compared to well-rested individuals, and crucially, a weakened connection between the amygdala and the medial prefrontal cortex that normally provides top-down regulation of emotional responses. Sleep deprivation does not merely make people more emotionally reactive. It appears to weaken the regulatory architecture that maintains the emotional regulation quality that leadership requires. The sleep-deprived leader is plausibly operating with a compromised prefrontal-amygdala regulatory system that produces the specific leadership failures documented in the emotional systems chapter: disproportionate threat responses, reduced empathy, impaired reading of others' emotional states, and the kind of emotionally reactive decision-making that damages trust and undermines the costly signal of emotional stability that genuine leadership requires.

The social cognitive dimension adds a third layer. Yoo and colleagues' (2007) research on sleep deprivation and emotional reactivity showed that sleep-deprived individuals showed markedly greater amygdala reactivity to emotionally negative images, with weaker regulation by the prefrontal cortex. This asymmetry may be relevant to leadership: the social attunement that genuine mentalising requires depends on reading the full range of emotional expression accurately, including the subtle positive and neutral states that genuine engagement, genuine confusion, genuine concern, and genuine enthusiasm produce. The chapter infers, going beyond a finding of greater reactivity to negative images, that sleep-deprived leaders may be specifically impaired in detecting the subtle positive social signals that indicate genuine followership and genuine engagement, while remaining sensitive to the strongly negative signals that indicate overt threat. The result, on this inference, would be a distortion of the social information environment in which threats are visible and positive signals are harder to see.

The organisational culture dimension of sleep deprivation connects individual biology to collective performance. Culture norms around sleep in many organisations, particularly those that associate long hours with commitment and treat sleep as a sign of insufficient dedication, systematically undermine the biological infrastructure of the leadership quality they claim to value. The leader who is celebrated for sending emails at 3am and presenting at 7am has demonstrated commitment at the cost of impairing the prefrontal executive function, emotional regulation capacity, and social attunement that the quality of their strategic contribution depends on. Organisations that create sleep-hostile cultures are not making a trade-off between effort and performance. They are systematically degrading the biological substrate of the leadership capability they require while receiving the visible signals of effort that the commitment culture values.

The practical implication is specific: genuine leadership performance infrastructure requires protecting the sleep quality of the organisation's most important decision-makers as deliberately as any other performance-critical resource. This means examining the structural features of leadership roles that most damage sleep quality, including always-on communication expectations, early morning and late evening meeting patterns, international travel schedules that produce chronic circadian disruption, and the cultural norms that treat sleep deprivation as a status signal rather than a performance liability.

What Genuine Organisational Health Looks Like

The evolutionary medicine framework generates specific and actionable principles for organisational health design that differ substantially from the welfare management approach that dominates current practice.

The first principle is environmental diagnosis before intervention design. Yusuf Osman's approach at Hartwell, spending three months diagnosing the environmental conditions producing the biological costs before designing any interventions, reflects the evolutionary medicine logic: understand what the symptoms are responding to before attempting to address them. The standard organisational health toolkit inverts this order, deploying wellness programmes, resilience training, and employee assistance resources before asking whether the environment they are helping people adapt to is the appropriate target of intervention.

The second principle is condition specificity over generic wellness. The evolutionary medicine framework identifies specific psychosocial conditions with specific biological consequences through specific mechanisms. Effective organisational health intervention targets the specific conditions producing the specific costs in specific parts of the organisation rather than deploying generic wellness programmes across the whole organisation regardless of the distribution of health costs. Yusuf's data showed that three of eight divisions were generating the majority of Hartwell's health costs: a generic firm-wide wellness programme would have distributed resources equally across all eight divisions, treating the symptom-free divisions with the same intensity as the ones generating the damage.

The third principle is control restoration as a primary intervention target. The demand-control-support literature consistently identifies low control as the most health-damaging of the three dimensions, and the evolutionary grounding of control-seeking provides a mechanistic explanation for why. Organisational interventions that increase genuine behavioural autonomy, reduce surveillance and micromanagement, expand the range of decisions that individuals can make about their own work, and create genuine flexibility in how work requirements are met will produce health benefits through the specific mechanism of allostatic load reduction that restored control enables.

The fourth principle is recovery design as a structural requirement. The mismatch between evolved recovery rhythms and modern work patterns requires deliberate structural accommodation rather than individual willpower. Organisational designs that build genuine recovery intervals into the work rhythm, that create and protect boundaries between work and non-work time, and that treat physical activity as a structural feature of the work environment rather than an individual lifestyle choice are addressing the mismatch at the level of environmental design rather than asking individuals to overcome it through personal effort.

Critical Examination: The Limits of Evolutionary Medicine as Organisational Framework

The evolutionary medicine framework is genuinely illuminating for organisational health but several important limitations require honest acknowledgement.

The causal inference problem is significant. The correlational evidence connecting psychosocial work conditions to health outcomes, including Marmot's Whitehall Studies and the extensive demand-control-support literature, is robust and consistent. But the causal mechanisms connecting specific management behaviours to specific health outcomes in specific individuals in specific organisational contexts involve inferential chains that the available evidence does not fully establish. The framework provides a plausible and well-supported account of the mechanisms. It does not provide the precision that individual-level causal attribution would require.

The individual variation problem is equally important. The evolutionary medicine framework describes average biological responses to specific environmental conditions. Individual variation in stress reactivity, autonomy preference, social support needs, and recovery rhythms is substantial, as the personality and epigenetics chapters established. Environmental design that addresses average needs will miss the specific needs of individuals whose profiles differ substantially from the average, and the most health-vulnerable individuals are often those whose profiles deviate most from the average in ways that generic environmental interventions do not reach.

The organisational complexity problem limits the precision of environmental diagnosis. Real organisations are not simple experimental environments where single causal factors can be isolated. The psychosocial work conditions that produce health costs are typically multiple, interacting, and confounded with factors including individual life circumstances, pre-existing health conditions, and non-work stressors that organisational interventions cannot address. Yusuf's diagnostic approach was sophisticated but it still involved attributing health costs to organisational conditions that were genuinely causal in aggregate without establishing specific causal pathways for specific individuals.

The ethics of surveillance concern is genuine. Using disaggregated health data to identify specific managers as the causal agents of workforce health costs requires careful ethical handling. The individuals whose management behaviour produces health costs have their own rights to privacy, due process, and supportive rather than punitive responses to identified difficulties. Yusuf's approach, which used the data to inform development and structural change rather than to trigger disciplinary action, represents one reasonable resolution of this tension, but the tension is real and requires deliberate rather than casual navigation.

Key takeaways

• Evolutionary medicine reframes biological symptoms from malfunctions to functional outputs of evolved systems responding accurately to environmental signals: the organisational health implication is that workforce health data is a biological readout of environmental conditions rather than a welfare metric, and the primary diagnostic question is what the symptoms are responding to rather than how to help employees tolerate them (Nesse and Williams, 1994).
• Chronic HPA axis activation from sustained psychosocial threat exposure produces specific biological costs including immune suppression, cardiovascular strain, and hippocampal atrophy through the allostatic load mechanism: the health costs that organisations attribute to individual vulnerability or lifestyle factors are frequently the accurate biological outputs of specific psychosocial work conditions that the demand-control-support research has been documenting for decades (McEwen, 1998; Marmot, 2004).
• The demand-control-support model identifies the most health-damaging psychosocial work condition combination with evolutionary grounding in specific mechanisms: high demands activate threat detection, low control plausibly activates learned helplessness, and low social support removes the buffering of stress that genuine social connection is thought to provide (Karasek, 1979; Johnson and Hall, 1988).
• Organisational mismatch with evolved biological requirements produces health costs through specific mechanisms that environmental design rather than individual adaptation is the appropriate primary response to: sedentary work mismatches activity requirements, open-plan density mismatches social bonding needs, always-on communication mismatches recovery rhythms, and autonomy deprivation mismatches the control-seeking that ancestral behavioural flexibility supported (Bernstein and Turban, 2018).
• Mental health difficulties in organisations are frequently the accurate outputs of evolved psychological systems responding to genuine environmental signals rather than primarily individual vulnerabilities: anxiety responds to genuine threat signals, low mood responds to genuine goal blockage, and social discomfort responds to genuine social threat, with the diagnostic implication that addressing the environmental signals is the primary intervention target (Nesse, 2019).
• Environmental diagnosis before intervention design is the core practical principle of evolutionary medicine applied to organisations: disaggregating health data by team, function, and manager to identify the specific environmental conditions generating the biological costs, before deploying any interventions, is argued to produce better outcomes than distributing generic wellness programmes uniformly across environments with very different health profiles; the Hartwell case is a before-and-after comparison with no comparison group, and it illustrates the argument without testing it.
• The evolutionary medicine framework does not eliminate the role of individual treatment and support but it reorders the organisational response: individual support for people experiencing health difficulties is appropriate and sometimes essential, but it should not substitute for environmental diagnosis and environmental change when the health data is accurately signalling that specific organisational conditions are the primary causal agents.

Reflection questions

• Review the health and absence data in your organisation disaggregated by team, function, and manager rather than as aggregate figures. What pattern does the disaggregated data reveal? Are health costs randomly distributed or clustering in specific environmental conditions? What does the clustering pattern suggest about the environmental causes the aggregate figures are obscuring?
• Examine the psychosocial work conditions in your organisation through the demand-control-support framework. Where are demands highest? Where is control lowest? Where is genuine social support most absent? Which combinations of these dimensions are being experienced by which parts of your workforce, and what do the evolutionary mechanisms predict about the biological costs those combinations are producing?
• Consider the specific mismatches between modern work conditions in your organisation and the ancestral environments for which human biology was calibrated. Where is sedentary posture most sustained? Where are circadian rhythms most disrupted? Where is autonomy most constrained? Where is genuine social connection most absent? Which of these mismatches could be addressed through environmental design rather than individual adaptation?
• Reflect on a significant health or absence problem you have encountered in your leadership experience. From the evolutionary medicine framework, was the standard organisational response primarily aimed at helping individuals tolerate their environment more effectively, or at diagnosing and addressing the environmental conditions the health data was responding to? What would the evolutionary medicine approach have changed?
• Consider the mental health difficulties that are most common in your organisation or team. From Nesse's functional response framework, what genuine environmental signals might those difficulties be accurately responding to? What changes to the psychosocial work environment would address those signals rather than just managing the responses they produce?
• Examine your own leadership behaviour through the demand-control-support lens. What specific aspects of how you manage work allocation, decision-making authority, and social infrastructure in your team affect the demand levels, control availability, and social support experienced by your direct reports? What does the evolutionary medicine framework suggest about the biological consequences of those specific practices?

References

1. Bernstein, E. S., & Turban, S. (2018). The impact of the 'open' workspace on human collaboration. Philosophical Transactions of the Royal Society B, 373(1753), 20170239.
2. Cannon, W. B. (1932). The wisdom of the body. Norton.
3. Deci, E. L., & Ryan, R. M. (1985). Intrinsic motivation and self-determination in human behavior. Plenum Press.
4. Gilbert, P. (1992). Depression: The evolution of powerlessness. Guilford Press.
5. Harrison, Y., & Horne, J. A. (1999). One night of sleep loss impairs innovative thinking and flexible decision making. Organizational Behavior and Human Decision Processes, 78(2), 128-145.
6. Johnson, J. V., & Hall, E. M. (1988). Job strain, work place social support, and cardiovascular disease: A cross-sectional study of a random sample of the Swedish working population. American Journal of Public Health, 78(10), 1336-1342.
7. Karasek, R. A. (1979). Job demands, job decision latitude, and mental strain: Implications for job redesign. Administrative Science Quarterly, 24(2), 285-308.
8. Marmot, M. (2004). The status syndrome: How social standing affects our health and longevity. Times Books.
9. McEwen, B. S. (1998). Stress, adaptation, and disease: Allostasis and allostatic load. Annals of the New York Academy of Sciences, 840(1), 33-44.
10. Nesse, R. M. (2019). Good reasons for bad feelings: Insights from the frontier of evolutionary psychiatry. Dutton.
11. Nesse, R. M., & Williams, G. C. (1994). Why we get sick: The new science of Darwinian medicine. Times Books.
12. Roenneberg, T., Allebrandt, K. V., Merrow, M., & Vetter, C. (2012). Social jetlag and obesity. Current Biology, 22(10), 939-943.
13. Sapolsky, R. M. (2004). Why zebras don't get ulcers (3rd ed.). Henry Holt.
14. Seligman, M. E. P. (1975). Helplessness: On depression, development, and death. Freeman.
15. Selye, H. (1956). The stress of life. McGraw-Hill.
16. Siegrist, J. (1996). Adverse health effects of high-effort and low-reward conditions. Journal of Occupational Health Psychology, 1(1), 27-41.
17. Walker, M. (2017). Why we sleep: Unlocking the power of sleep and dreams. Scribner.