How evolutionary behavioural sciences can help us understand behaviour in a pandemic

Role of leadership and incentive-based programs in addressing vaccine hesitancy in India

The current study goes beyond the popular 5Cs model of vaccine hesitancy to explore perceived social norms, role of leadership and the role of incentive-based intervention for improving the likelihood of vaccination, in a population-representative sample of adults in India (N = 1129). We investigated differences in socio-demographic status, perceived descriptive norms like vaccine behaviours, beliefs, experience and perceived injunctive norms like community and political leadership within the context of the COVID-19 pandemic are related to vaccination. Further, we examined the role of incentive-based intervention as a potentially salient predictor of adults' vaccine uptake. The study is based on a cross-sectional survey conducted in July-November 2021, which included questions about impacts of pandemic collected by phone call interview from adults' beneficiaries of Government free food schemes, across 11 states in India. The data include 81 % vaccinated and 19 % vaccine hesitant participants, with a higher proportion of business or self-employed (53.1 %) as vaccine hesitant. We performed the t-test to assess the variation between vaccinated and vaccine hesitant adults, and Exploratory Factor Analysis to uncover the underlying dimension of vaccine hesitancy. Subsequently, Binary Logistic Regression model probed the factors associated with likelihood of vaccination uptake. In contrast to the prevailing evidence, results demonstrated community and political leadership has significant negative impact on vaccination (p-value < 0.06, 95 % CI, 0.57-1.01). Incentive-based intervention offer a vital leverage to enhance positive attitude towards vaccination (p-value < 0.05, 95 % CI, 1.01-1.80). The results thus broadly highlight the limited role of political and community leaders in leveraging their influence on vaccination, the role of timely, accurate information, applications of telemedicine as an important tool to provide healthcare and the need for optimal design of incentive-based vaccination programs recommended by trusted sources.

Introducing the Neuroplastic Narrative: a non-pathologizing biological foundation for trauma-informed and adverse childhood experience aware approaches

Most people accessing mental health services have adverse childhood experiences (ACEs) and/or histories of complex trauma. In recognition of this, there are calls to move away from medical model approaches and move toward trauma-informed approaches which privilege the impact of life experience over underlying pathology in the etiology of emotional and psychological suffering. Trauma-informed approaches lack a biological narrative linking trauma and adversity to later suffering. In its absence, this suffering is diagnosed and treated as a mental illness. This study articulates the Neuroplastic Narrative, a neuroecological theory that fills this gap, conceptualizing emotional and psychological suffering as the cost of surviving and adapting to the impinging environments of trauma and adversity. The Neuroplastic Narrative privileges lived experience and recognizes that our experiences become embedded in our biology through evolved mechanisms that ultimately act to preserve survival in the service of reproduction. Neuroplasticity refers to the capacity of neural systems to adapt and change. Our many evolved neuroplastic mechanisms including epigenetics, neurogenesis, synaptic plasticity, and white matter plasticity allow us to learn from, and adapt to, past experiences. This learning and adaption in turn allows us to better anticipate and physiologically prepare for future experiences that (nature assumes) are likely to occur, based on past experiences. However, neuroplastic mechanisms cannot discriminate between experiences; they function to embed experience regardless of the quality of that experience, generating vicious or virtuous cycles of psychobiological anticipation, to help us survive or thrive in futures that resemble our privileged or traumatic pasts. The etiology of suffering that arises from this process is not a pathology (a healthy brain is a brain that can adapt to experience) but is the evolutionary cost of surviving traumatizing environments. Misidentifying this suffering as a pathology and responding with diagnosis and medication is not trauma-informed and may cause iatrogenic harm, in part through perpetuating stigma and exacerbating the shame which attends complex trauma and ACEs. As an alternative, this study introduces the Neuroplastic Narrative, which is situated within an evolutionary framework. The Neuroplastic Narrative complements both Life History and Attachment Theory and provides a non-pathologizing, biological foundation for trauma-informed and Adverse Childhood Experience aware approaches.

The impact of COVID-19 lockdown on postpartum mothers in London, England: An online focus group study

Aims

This study examines the impact of COVID-19 lockdown on postpartum mothers in England, with the aim of identifying opportunities to improve maternal experience and wellbeing. The postpartum/postnatal period is widely acknowledged as a time when mothers require greater levels of support from multiple sources. However, stay-at-home orders, commonly known as "lockdown," deployed in some countries to limit COVID-19 transmission reduced access to support. In England, many postpartum mothers navigated household isolation within an intensive mothering and expert parenting culture. Examining the impact of lockdown may reveal strengths and weaknesses in current policy and practice.

Subject and methods

We conducted online focus groups involving 20 mothers living in London, England, with "lockdown babies," following up on our earlier online survey on social support and maternal wellbeing. We thematically analysed focus group transcripts, and identified key themes around Lockdown Experience and Determinants of Lockdown Experience.

Results

Participants raised some positives of lockdown, including fostering connections and protection from external expectations, but also raised many negatives, including social isolation, institutional abandonment, and intense relationships within the household. Potential reasons behind variations in lockdown experience include physical environments, timing of birth, and number of children. Our findings reflect how current systems may be "trapping" some families into the male-breadwinner/female-caregiver family model, while intensive mothering and expert parenting culture may be increasing maternal stress and undermining responsive mothering.

Conclusions

Facilitating partners to stay at home during the postpartum period (e.g., increasing paternity leave and flexible working) and establishing peer/community support to decentre reliance on professional parenting experts may promote positive postpartum maternal experience and wellbeing.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-023-01922-4.

Effective incentives for increasing COVID-19 vaccine uptake

In this study, we examined the relative effectiveness of prestige-based incentives (vaccination of an expert scientist/president/politician/celebrity/religious leader), conformist incentives (vaccination of friends and family) and risk-based incentives (witnessing death or illness of a person from the disease) for increasing participants' chances of getting vaccinated with respect to their coronavirus disease 2019 (COVID-19) vaccine intention. We conducted a cross-cultural survey using demographically representative samples from the UK (n = 1533), USA (n = 1550) and Turkey (n = 1567). The most effective incentives in all three countries were vaccination of an expert scientist, followed by vaccination of friends and family members and knowing someone dying from the disease. Vaccination of an expert scientist was significantly more effective at increasing vaccine intention than any other incentive. Vaccine incentives, regardless of the incentive type, were much less effective for those who originally refused the COVID-19 vaccine than for those who were hesitant to receive the vaccine. Although the percentage of vaccine-hesitant participants was highest in Turkey, the mean effectiveness scores of incentives were also the highest in Turkey, suggesting that an informed vaccine promotion strategy can be successful in this country. Our findings have policy applicability and suggest that positive vaccination messages delivered by expert scientists, vaccination of friends and family and risk-based incentives can be effective at increasing vaccine uptake.

Gendered conflict in the human family

Sexual conflict is a thriving area of animal behaviour research. Yet parallel research in the evolutionary human sciences remains underdeveloped and has become mired by controversy. In this special collection, we aim to invigorate the study of fitness-relevant conflicts between women and men, advocating for three synergistic research priorities. First, we argue that a commitment to diversity is required to innovate the field, achieve ethical research practice, and foster fruitful dialogue with neighbouring social sciences. Accordingly, we have prioritised issues of diversity as editors, aiming to stimulate new connections and perspectives. Second, we call for greater recognition that human sex/gender roles and accompanying conflict behaviours are both subject to natural selection and culturally determined. This motivates our shift in terminology from sexual to gendered conflict when addressing human behaviour, countering stubborn tendencies to essentialise differences between women and men and directing attention to the role of cultural practices, normative sanctions and social learning in structuring conflict battlegrounds. Finally, we draw attention to contemporary policy concerns, including the wellbeing consequences of marriage practices and the gendered implications of market integration. Focus on these themes, combined with attendance to the dangers of ethnocentrism, promises to inform culturally sensitive interventions promoting gender equality worldwide.

The future of evolutionary medicine: sparking innovation in biomedicine and public health

Evolutionary medicine - i.e. the application of insights from evolution and ecology to biomedicine - has tremendous untapped potential to spark transformational innovation in biomedical research, clinical care and public health. Fundamentally, a systematic mapping across the full diversity of life is required to identify animal model systems for disease vulnerability, resistance, and counter-resistance that could lead to novel clinical treatments. Evolutionary dynamics should guide novel therapeutic approaches that target the development of treatment resistance in cancers (e.g., via adaptive or extinction therapy) and antimicrobial resistance (e.g., via innovations in chemistry, antimicrobial usage, and phage therapy). With respect to public health, the insight that many modern human pathologies (e.g., obesity) result from mismatches between the ecologies in which we evolved and our modern environments has important implications for disease prevention. Life-history evolution can also shed important light on patterns of disease burden, for example in reproductive health. Experience during the COVID-19 (SARS-CoV-2) pandemic has underlined the critical role of evolutionary dynamics (e.g., with respect to virulence and transmissibility) in predicting and managing this and future pandemics, and in using evolutionary principles to understand and address aspects of human behavior that impede biomedical innovation and public health (e.g., unhealthy behaviors and vaccine hesitancy). In conclusion, greater interdisciplinary collaboration is vital to systematically leverage the insight-generating power of evolutionary medicine to better understand, prevent, and treat existing and emerging threats to human, animal, and planetary health.

Group identities can undermine social tipping after intervention

Social tipping can accelerate behaviour change consistent with policy objectives in diverse domains from social justice to climate change. Hypothetically, however, group identities might undermine tipping in ways that policymakers do not anticipate. To examine this, we implemented an experiment around the 2020 US federal elections. The participants faced consistent incentives to coordinate their choices. Once the participants had established a coordination norm, an intervention created pressure to tip to a new norm. Our control treatment used neutral labels for choices. Our identity treatment used partisan political images. This simple pay-off-irrelevant relabelling generated extreme differences. The control groups developed norms slowly before intervention but transitioned to new norms rapidly after intervention. The identity groups developed norms rapidly before intervention but persisted in a state of costly disagreement after intervention. Tipping was powerful but unreliable. It supported striking cultural changes when choice and identity were unlinked, but even a trivial link destroyed tipping entirely.

Does higher perceived risk of morbidity and mortality decrease risk-taking?

Previous studies have shown that people change their behaviour in response to negative shocks such as economic downturns or natural catastrophes. Indeed, the optimal behaviour in terms of inclusive fitness often varies according to a number of parameters, such as the level of mortality risk in the environment. Beyond unprecedented restrictions in everyday life, the COVID-19 pandemic has profoundly affected people's environment. In this study, we investigated how people form their perception of morbidity and mortality risk associated with COVID-19 and how this perception in turn affects psychological traits, such as risk-taking and patience. We analysed data from a large survey conducted during the first wave in France on 3353 nationally representative people. We found that people use public information on COVID-19 deaths in the area where they live to form their perceived morbidity and mortality risk. Using a structural model approach to lift endogeneity concerns, we found that higher perceived morbidity and mortality risk increases risk aversion. We also found that higher perceived morbidity and mortality risk leads to less patience, although this was only observed for high levels of perceived risk. Our results suggest that people adapt their behaviour to anticipated negative health shocks, namely the risk of becoming sick or dying of COVID-19.

The Future of Infodemic Surveillance as Public Health Surveillance

Public health systems need to be able to detect and respond to infodemics (outbreaks of misinformation, disinformation, information overload, or information voids). Drawing from our experience at the US Centers for Disease Control and Prevention, the COVID-19 State of Vaccine Confidence Insight Reporting System has been created as one of the first public health infodemic surveillance systems. Key functions of infodemic surveillance systems include monitoring the information environment by person, place, and time; identifying infodemic events with digital analytics; conducting offline community-based assessments; and generating timely routine reports. Although specific considerations of several system attributes of infodemic surveillance system must be considered, infodemic surveillance systems share several similarities with traditional public health surveillance systems. Because both information and pathogens are spread more readily in an increasingly hyperconnected world, sustainable and routine systems must be created to ensure that timely interventions can be deployed for both epidemic and infodemic response.

A. M, Park A, Parveen S, Kim S. Evolution and consequences of individual responses during the COVID-19 outbreak

In a long-lasting major disease outbreak such as that of COVID-19, the challenge for public health authorities is to keep people motivated and keen on following safety guidelines. In this study, a compartmental model with a heterogeneous transmission rate (based on awareness) is utilized to hypothesize about the public adoption of preventive guidelines. Three subsequent outbreaks in South Korea, Pakistan, and Japan were analyzed as case studies. The transmission, behavior change, and behavioral change ease rates of the disease were measured in these countries. The parameters were estimated using the maximum likelihood method with an additional identifiability analysis performed to determine the uniqueness of the estimated parameters for quantitatively comparing them during the first three waves of COVID-19. The mathematical analysis and simulation results show that individual responses had a significant effect on the outbreak. Individuals declining to follow the public health guidelines in Korea and Japan between the second and third waves contributed to making the third peak the highest of the three peaks. In Pakistan, however, individual responses to following public health guidelines were maintained between the second and third waves, resulting in the third peak being lower than the first, rather than being associated with the highest transmission rate. Thus, maintaining a high level of awareness is critical for containing the spread. Improvised public health campaigns are recommended to sustain individual attention and maintain a high level of awareness.

How evolutionary science can help us understand vaccine refusal in the COVID-19 pandemic

Unvaccinated people have a mortality rate from COVID-19 that is 32-fold that of fully vaccinated people. Yet, in the UK, more than 4% of adults have not accepted a vaccine to protect them against COVID-19 and at the time of writing only 73% of people were fully vaccinated. Psychological and societal factors underlying vaccine hesitation or refusal are complex. In this paper, we use evolutionary science to help explain how vaccine refusal can be the result of an historic adaptation to protect against the repetition of past trauma, including, for many, that of systemic racism and/or deprivation, and misguided attempt to preserve fertility. We discuss some resulting cognitive biases and conclude with recommendations for practice.

Does social influence affect COVID-19 vaccination intention among the unvaccinated?

Conformist social influence is a double-edged sword when it comes to vaccine promotion. On the one hand, social influence may increase vaccine uptake by reassuring the hesitant about the safety and effectiveness of the vaccine; on the other hand, people may forgo the cost of vaccination when the majority is already vaccinated - giving rise to a public goods dilemma. Here, we examine whether available information on the percentage of double-vaccinated people affects COVID-19 vaccination intention among unvaccinated people in Turkey. In an online experiment, we divided participants (n = 1013) into low, intermediate and high social influence conditions, reflecting the government's vaccine promotion messages. We found that social influence did not predict COVID-19 vaccination intention, but psychological reactance and collectivism did. People with higher reactance (intolerance of others telling one what to do and being sceptical of consensus views) had lower vaccination intention, whilst people with higher collectivism (how much a person considers group benefits over individual success) had higher vaccination intention. Our findings suggest that advertising the percentage of double-vaccinated people is not sufficient to trigger a cascade of others getting themselves vaccinated. Diverse promotion strategies reflecting the heterogeneity of individual attitudes could be more effective.

The evolution of the human healthcare system and implications for understanding our responses to COVID-19

The COVID-19 pandemic has revealed an urgent need for a comprehensive, multidisciplinary understanding of how healthcare systems respond successfully to infectious pathogens-and how they fail. This study contributes a novel perspective that focuses on the selective pressures that shape healthcare systems over evolutionary time. We use a comparative approach to trace the evolution of care-giving and disease control behaviours across species and then map their integration into the contemporary human healthcare system. Self-care and pro-health environmental modification are ubiquitous across animals, while derived behaviours like care for kin, for strangers, and group-level organizational responses have evolved via different selection pressures. We then apply this framework to our behavioural responses to COVID-19 and demonstrate that three types of conflicts are occurring: (1) conflicting selection pressures on individuals, (2) evolutionary mismatches between the context in which our healthcare behaviours evolved and our globalized world of today and (3) evolutionary displacements in which older forms of care are currently dispensed through more derived forms. We discuss the significance of understanding how healthcare systems evolve and change for thinking about the role of healthcare systems in society during and after the time of COVID-19-and for us as a species as we continue to face selection from infectious diseases.

The effect of human vaccination behaviour on strain competition in an infectious disease: An imitation dynamic approach

Strain competition plays an important role in shaping the dynamics of multiple pathogen outbreaks in a population. Competition may lead to exclusion of some pathogens, while it may influence the invasion of an emerging mutant in the population. However, little emphasis has been given to understand the influence of human vaccination choice on pathogen competition or strain invasion for vaccine-preventable infectious diseases. Coupling game dynamic framework of vaccination choice and compartmental disease transmission model of two strains, we explore invasion and persistence of a mutant in the population despite having a lower reproduction rate than the resident one. We illustrate that higher perceived strain severity and lower perceived vaccine efficacy are necessary conditions for the persistence of a mutant strain. The numerical simulation also extends these invasion and persistence analyses under asymmetric cross-protective immunity of these strains. We show that the dynamics of this cross-immunity model under human vaccination choices is determined by the interplay of parameters defining the cross-immune response function, perceived risk of infection, and vaccine efficacy, and it can exhibit invasion and persistence of mutant strain, even complete exclusion of resident strain in the regime of sufficiently high perceived risk. We conclude by discussing public health implications of the results, that proper risk communication in public about the severity of the disease is an important task to reduce the chance of mutant invasion. Thus, understanding pathogen competitions under social interactions and choices may be an important component for policymakers for strategic decision-making.

Adaptive function and correlates of anxiety during a pandemic

BACKGROUND AND OBJECTIVES

Most studies to date have focused on the negative aspects of anxiety. Anxiety, however, is an evolved emotional response that can provide protection in the face of risk. Pandemics are characterized by increased mortality risk coupled with future uncertainties, which both cause heightened anxiety. Here, we examine the factors associated with anxiety levels and risk avoidance behaviours during the first wave of the COVID-19 pandemic. We asked how individual time perspectives (future-oriented consideration and attention to present moment experience) affect anxiety in uncertain times, and whether anxiety reduces mortality risk by promoting risk avoidance behaviour.

METHODOLOGY

We conducted an online survey in the UK (N = 1088) and Turkey (N = 3935) and measured participants' generalized and pandemic-related anxiety levels, future-oriented consideration, mindfulness, intolerance of uncertainty, risk perception and risk avoidance behaviours.

RESULTS

We found that people less tolerant of uncertainties had higher levels of pandemic anxiety. Those with higher pandemic anxiety exhibited risk avoidance behaviours more frequently. Mindfulness and increased financial satisfaction reduced pandemic anxiety. People in Turkey reported higher levels of generalized and pandemic anxiety and greater engagement in risk avoidance behaviours than people in the UK.

CONCLUSIONS AND IMPLICATIONS

Our study shows an elevated anxiety response can help mitigate infection risk during pandemics and emphasizes the importance of the underlying situation in understanding whether an anxiety response is adaptive or pathological. Maintaining a healthy level of anxiety can promote engagement in protective behaviours. Therapies addressing anxiety can focus on increasing tolerance to future uncertainties.

LAY SUMMARY

Anxiety is an emotional response triggered in the anticipation of a possible threat. We found that intolerance of uncertainty strongly predicted anxiety and that people with elevated anxiety levels engaged in protective behaviours more frequently during the COVID-19 pandemic, suggesting that anxiety can help mitigate mortality risk.

The Effect of the COVID-19 on Corrosive Ingestion in Thailand

Purpose

Since January 2020, the outbreak of COVID-19 coronavirus has impacted global mental health, daily activities, and economies, including Thailand. The essential strategy is the disease-preventing measure of “lockdown.” Corrosive ingestion is one of the most common forms of self-harm and problems worldwide. This study aimed to evaluate the effect of corrosive ingestion in the COVID-19 situation.

Methods

This was a retrospective study of adult patients (≥18y) who had ingested corrosives and been admitted to surgical department, Thammasat University Hospital between June and December 2019 (pre-COVID-19) and January to June 2020 (COVID-19 period) and compared the epidemiological and clinical features between these two groups.

Results

Nine and 20 patients were admitted in the pre-COVID-19 and COVID-19 periods, for an increase of 122%; males numbered 15. A minority of ingestions, 8/29, were intentional of which 7 were in the COVID-19 period. The Zargar classification showed a trend towards more gastric injury in the COVID-19 vs pre-COVID-19 periods: 8/17 vs 1/9 (p=0.09). Because of the endoscopic grade 0 in stomach was significantly higher in pre-COVID-19 than COVID-19 case (pre-COVID-19; 8 patients (88.9%), COVID-19; 9 patients (45%); p value 0.011).

Conclusion

Data from this study suggest increasing trends of corrosive ingestion and greater gastric injury during the COVID-19 period.

Identifying Resilience Factors of Distress and Paranoia During the COVID-19 Outbreak in Five Countries

The ongoing COVID-19 pandemic outbreak has affected all countries with more than 100 million confirmed cases and over 2.1 million casualties by the end of January 2021 worldwide. A prolonged pandemic can harm global levels of optimism, regularity, and sense of meaning and belonging, yielding adverse effects on individuals' mental health as represented by worry, paranoia, and distress. Here we studied resilience, a successful adaptation despite risk and adversity, in five countries: Brazil, Colombia, Germany, Israel, and Norway. In April 2020, over 2,500 participants were recruited for an observational study measuring protective and obstructive factors for distress and paranoia. More than 800 of these participants also completed a follow-up study in July. We found that thriving, keeping a regular schedule, engaging in physical exercise and less procrastination served as factors protecting against distress and paranoia. Risk factors were financial worries and a negative mindset, e.g., feeling a lack of control. Longitudinally, we found no increase in distress or paranoia despite an increase in expectation of how long the outbreak and the restrictions will last, suggesting respondents engaged in healthy coping and adapting their lives to the new circumstances. Altogether, our data suggest that humans adapt even to prolonged stressful events. Our data further highlight several protective factors that policymakers should leverage when considering stress-reducing policies.

Communication Across Maternal Social Networks During England's First National Lockdown and Its Association With Postnatal Depressive Symptoms

Postnatal/postpartum depression (PND/PPD) had a pre-COVID-19 estimated prevalence ranging up to 23% in Europe, 33% in Australia, and 64% in America, and is detrimental to both mothers and their infants. Low social support is a key risk factor for developing PND. From an evolutionary perspective this is perhaps unsurprising, as humans evolved as cooperative childrearers, inherently reliant on social support to raise children. The coronavirus pandemic has created a situation in which support from social networks beyond the nuclear family is likely to be even more important to new mothers, as it poses risks and stresses for mothers to contend with; whilst at the same time, social distancing measures designed to limit transmission create unprecedented alterations to their access to such support. Using data from 162 mothers living in London with infants aged ≤6 months, we explore how communication with members of a mother's social network related to her experience of postnatal depressive symptoms during the first "lockdown" in England. Levels of depressive symptoms, as assessed via the Edinburgh Postnatal Depression Scale, were high, with 47.5% of the participants meeting a ≥11 cut-off for PND. Quasi-Poisson regression modelling found that the number of network members seen in-person, and remote communication with a higher proportion of those not seen, was negatively associated with depressive symptoms; however, contact with a higher proportion of relatives was positively associated with symptoms, suggesting kin risked seeing mothers in need. Thematic qualitative analysis of open text responses found that mothers experienced a burden of constant mothering, inadequacy of virtual contact, and sadness and worries about lost social opportunities, while support from partners facilitated family bonding. While Western childrearing norms focus on intensive parenting, and fathers are key caregivers, our results highlight that it still "takes a village" to raise children in high-income populations and mothers are struggling in its absence.

Spatial and Social Behavior of Single and Coupled Individuals of Both Sexes during COVID-19 Lockdown Regime in Russia

Testing individual motivations for social activity in violation of the mandated lockdown regime is a challenging research topic for evolutionary psychology. To this purpose, we analyzed twenty popular weekly routes and the potential impact of sex and relationship status (single versus coupled) on the reported level of spatial-social activity during the quarantine in Russia between March and June 2020 (N = 492). Our study revealed a significant difference between men’s and women’s mobility: men, in general, tend to exhibit substantially higher spatial activity. The results have shown that individuals living on their own have more social interactions with friends and exhibit more profound spatial mobility via public transport. On the other hand, spatial activity of coupled individuals of both sexes were mostly devoted to solving a list of economic and matrimonial tasks. At the same time, men already cohabiting with a partner leave their homes for dating purposes more frequently than single men and women. We interpret these findings in the sense that both individual and sex-specific differences in observed sociality could be a result of a fine-tuned adaptive populational response to a contemporary virus threat, predominantly rooted in the evolution of behavioral strategies in the reproductive and economic spheres of each sex. Indeed, unlike women, coupled men have been preserving highly risky and intense social behavior during the COVID-19 pandemic.

COVID-19 Pandemic on Fire: Evolved Propensities for Nocturnal Activities as a Liability Against Epidemiological Control

Humans have been using fire for hundreds of millennia, creating an ancestral expansion toward the nocturnal niche. The new adaptive challenges faced at night were recurrent enough to amplify existing psychological variation in our species. Night-time is dangerous and mysterious, so it selects for individuals with higher tendencies for paranoia, risk-taking, and sociability (because of security in numbers). During night-time, individuals are generally tired and show decreased self-control and increased impulsive behaviors. The lower visibility during night-time favors the partial concealment of identity and opens more opportunities for disinhibition of self-interested behaviors. Indeed, individuals with an evening-oriented chronotype are more paranoid, risk-taking, extraverted, impulsive, promiscuous, and have higher antisocial personality traits. However, under some circumstances, such as respiratory pandemics, the psychobehavioral traits favored by the nocturnal niche might be counter-productive, increasing contagion rates of a disease that can evade the behavioral immune system because its disease cues are often nonexistent or mild. The eveningness epidemiological liability hypothesis presented here suggests that during the COVID-19 pandemic, the evening-oriented psychobehavioral profile can have collectively harmful consequences: there is a clash of core tendencies between the nocturnal chronotype and the recent viral transmission-mitigating safety guidelines and rules. The pandemic safety protocols disrupt much normal social activity, particularly at night when making new social contacts is desired. The SARS-CoV-2 virus is contagious even in presymptomatic and asymptomatic individuals, which enables it to mostly evade our evolved contagious disease avoidance mechanisms. A growing body of research has indirectly shown that individual traits interfering with social distancing and anti-contagion measures are related to those of the nocturnal chronotype. Indeed, some of the social contexts that have been identified as superspreading events occur at night, such as in restaurants, bars, and nightclubs. Furthermore, nocturnal environmental conditions favor the survival of the SARS-CoV-2 virus much longer than daytime conditions. We compare the eveningness epidemiological liability hypothesis with other factors related to non-compliance with pandemic safety protocols, namely sex, age, and life history. Although there is not yet a direct link between the nocturnal chronotype and non-compliance with pandemic safety protocols, security measures and future empirical research should take this crucial evolutionary mismatch and adaptive metaproblem into account, and focus on how to avoid nocturnal individuals becoming superspreaders, offering secure alternatives for nocturnal social activities.

Noncompliance With Safety Guidelines as a Free-Riding Strategy: An Evolutionary Game-Theoretic Approach to Cooperation During the COVID-19 Pandemic

Evolutionary game theory and public goods games offer an important framework to understand cooperation during pandemics. From this perspective, the COVID-19 situation can be conceptualized as a dilemma where people who neglect safety precautions act as free riders, because they get to enjoy the benefits of decreased health risk from others' compliance with policies despite not contributing to or even undermining public safety themselves. At the same time, humans appear to carry a suite of evolved psychological mechanisms aimed at curbing free riding in order to ensure the continued provision of public goods, which can be leveraged to develop more effective measures to promote compliance with regulations. We also highlight factors beyond free riding that reduce compliance rates, such as the emergence of conspiratorial thinking, which seriously undermine the effectiveness of measures to suppress free riding. Together, the current paper outlines the social dynamics that occur in public goods dilemmas involving the spread of infectious disease, highlights the utility and limits of evolutionary game-theoretic approaches for COVID-19 management, and suggests novel directions based on emerging challenges to cooperation.

Pandemic Leadership: Sex Differences and Their Evolutionary-Developmental Origins

The COVID-19 pandemic has caused a global societal, economic, and social upheaval unseen in living memory. There have been substantial cross-national differences in the kinds of policies implemented by political decision-makers to prevent the spread of the virus, to test the population, and to manage infected patients. Among other factors, these policies vary with politicians' sex: early findings indicate that, on average, female leaders seem more focused on minimizing direct human suffering caused by the SARS-CoV-2 virus, while male leaders implement riskier short-term decisions, possibly aiming to minimize economic disruptions. These sex differences are consistent with broader findings in psychology, reflecting women's stronger empathy, higher pathogen disgust, health concern, care-taking orientation, and dislike for the suffering of other people-as well as men's higher risk-taking, Machiavellianism, psychopathy, narcissism, and focus on financial indicators of success and status. This review article contextualizes sex differences in pandemic leadership in an evolutionary framework. Evolution by natural selection is the only known process in nature that organizes organisms into higher degrees of functional order, or counteracts the unavoidable disorder that would otherwise ensue, and is therefore essential for explaining the origins of human sex differences. Differential sexual selection and parental investment between males and females, together with the sexual differentiation of the mammalian brain, drive sex differences in cognition and behavioral dispositions, underlying men's and women's leadership styles and decision-making during a global pandemic. According to the sexually dimorphic leadership specialization hypothesis, general psychobehavioral sex differences have been exapted during human evolution to create sexually dimorphic leadership styles. They may be facultatively co-opted by societies and/or followers when facing different kinds of ecological and/or sociopolitical threats, such as disease outbreaks or intergroup aggression. Early evidence indicates that against the invisible viral foe that can bring nations to their knees, the strategic circumspection of empathic feminine health "worriers" may bring more effective and humanitarian outcomes than the devil-may-care incaution of masculine risk-taking "warriors".