This article provides a comprehensive introduction to “Social Safety Theory: Conceptual foundation, underlying mechanisms, and future directions,” a paper authored by George M. Slavich and colleagues, published in Health Psychology Review in 2023.
1. Addressing Limitations of Classic Stress Theories The paper begins by identifying persistent issues in classic theories of stress and health. Despite extensive research showing the significant impact of social factors on health, longevity, and behavior, there has been little consensus on which specific social factors are most beneficial or harmful for health. This ambiguity has resulted in conceptual, measurement, and reproducibility challenges in the field. Historically, stress, coping, and resilience theories were built on assumptions about how social experiences might affect health-relevant biology, often leading to “armchair theorizing” not fully aligned with the evolved regulatory logic of underlying biological systems.
2. Social Safety Theory’s Novel Approach To overcome these limitations, Social Safety Theory (SST) proposes a new, biologically grounded approach. Instead of speculating about social factors, SST uses knowledge about the primary goal and regulatory logic of the human brain and immune system to predict which social situations should elicit the strongest responses from these health-relevant biological systems. The core evolutionary premise is that these systems evolved to maximize reproductive success and survival. This evolutionarily informed perspective aims to refine the fundamental understanding of stress biology and health.
3. Key Tenets of Social Safety Theory SST is built upon three main tenets:
- Tenet 1: Humans evolved to foster social safety – exhibiting a fundamental drive to develop and maintain friendly social bonds, especially with in-group members.
- Tenet 2: Social safety is beneficial for human health and behavior – experiences indicating safety have broad benefits for various health and behavioral outcomes, including longevity.
- Tenet 3: Social threat is harmful to human health and behavior – experiences indicating threat are associated with various negative health and behavioral outcomes, including mortality.
4. Key Constructs of Social Safety Theory SST encompasses three core constructs that influence how social experiences affect health:
- Socially Safe and Socially Threatening Situations: These refer to the observable characteristics of a particular life event or social situation.
- Socially safe situations are characterized by acceptance, understanding, inclusion, connection, belonging, harmony, support, validation, predictability, stability, and authenticity, which would have conferred evolutionary benefits.
- Socially threatening situations involve conflict, aggression, devaluation, criticism, disapproval, discrimination, isolation, rejection, exclusion, turbulence, unpredictability, manipulation, and betrayal, which would have conferred evolutionary costs.
- For an experience to be considered “social,” it must involve an interpersonal exchange or have direct interpersonal implications, even if the initial stressor seems nonsocial (e.g., a poor exam score leading to social criticism).
- Perceived Social Safety and Social Threat: These represent an individual’s appraisal of a specific social situation. While influenced by objective characteristics, these perceptions are distinct (e.g., interpreting an ambiguous situation as socially rejecting). These individual differences in appraisal are crucial because they strongly influence the downstream biological consequences for health and behavior.
- Social Safety Schemas: These are cognitive representations of the social self, social world, and social future, specifically involving dimensions of social safety and threat.
- Social self-schemas concern one’s own characteristics related to belonging, lovability, worthiness of respect, and coping abilities in interpersonal situations.
- Social world schemas reflect general perceptions of others as friendly or hostile, predictable or unreliable, supportive or critical.
- Social future schemas involve expectations about future social inclusion/isolation, stability/instability, and success/failure. These schemas are shaped by a person’s lifetime social experiences, messages received (especially during sensitive developmental periods like childhood and adolescence), and interpretations of these events. They are relatively trait-like but can change due to impactful life events. SST posits that social safety and social threat are not mutually exclusive, meaning a situation or relationship can involve elements of both simultaneously (e.g., constructive criticism).
5. Underlying Mechanisms: The Biobehavioral Response to Social Threat SST is grounded in the understanding that the primary purpose of the human brain and immune system is to keep the body biologically and physically safe.
- The brain constantly monitors the social environment, interpreting social signals and judging the extent of social safety versus threat.
- This appraisal is supported by the amygdala network, mentalizing network, empathy network, and mirror neuron system (the “social brain”).
- When a potential social threat is perceived, the brain activates a multi-level response mediated by social signal transduction pathways: the sympathetic nervous system (SNS), hypothalamic–pituitary–adrenal (HPA) axis, vagus nerve, and meningeal lymphatic vessels.
- The evolutionary logic is that social threats (e.g., conflict, aggression, exclusion) historically increased the risk of physical injury and infection. Thus, the brain and immune system evolved to mount anticipatory responses to these social cues.
- For instance, SNS activation upregulates proinflammatory immune response genes (e.g., IL1B, IL6, TNF) while suppressing antiviral genes. The HPA axis, through cortisol, generally reduces both antiviral and inflammatory gene expression, but can increase inflammation under chronic conditions (e.g., glucocorticoid insensitivity).
- While intermittent inflammatory responses to social threat are adaptive (preparing the body for potential injury or infection), sustained or chronic activation due to persistent social threat (even imagined) can lead to chronic inflammation, reduced glucocorticoid receptor sensitivity, increased social stress generation, and modified social safety schemas. This chronic inflammation, in turn, increases the risk of chronic diseases (e.g., depression, heart disease, neurodegenerative disorders), biological aging, and early mortality. SST highlights this as an evolutionary mismatch in modern environments where physical combat is less common, but the biological response persists.
6. Developmental Perspective SST provides a framework for understanding how social safety and threat affect biological functioning and health across the lifespan, especially during sensitive developmental periods such as prenatal development, childhood, and puberty.
- Early-Life Calibration: Early-life environmental conditions, particularly social safety and threat, can create a “blueprint” for how an individual’s biological stress response systems (like the HPA axis and immune system) are calibrated. For example, childhood adversity is linked to long-term dysregulation of psychobiological systems and a “defensive” phenotype characterized by altered neurocognitive, HPA axis, HPG axis, and immune system functioning. This calibration, while potentially damaging in the long term, is designed to increase survival and reproduction odds in the perceived environment.
- Puberty: This is another significant period for restructuring the biological stress response due to its evolutionary importance for survival and reproduction. Adolescents become hypersensitive to social cues, and social threats around puberty may particularly restructure HPA axis dynamics.
- Oxytocin System: Beyond the HPA axis, the oxytocin system plays a key role in regulating social stress-related processes and is highly malleable during critical developmental transitions like puberty. Higher oxytocin levels may promote social safety and mitigate the negative health effects of social threat, potentially by modulating the immune system.
- Immune System Development: Perinatal inflammation can sensitize the developing brain and immune system to later injury and chronic CNS inflammation, potentially leading to a positive feedback loop affecting immune function and social functioning throughout development. The co-regulation between immune-inflammatory development and social processes appears to strengthen after puberty and can be remodeled by significant life events throughout adulthood.
- Development of Social Safety Schemas: These schemas are structured and restructured most prominently during infancy, childhood, and puberty, and are also influenced by major life stressors. Parenting styles, adverse childhood experiences (ACEs), and even subtle messages can shape these schemas, affecting how individuals perceive the social self, world, and future.
7. Role of Culture and Social Institutions SST offers a framework for investigating how complex social networks and connections within broader social circles and institutions (e.g., families, schools, governments, economic systems) affect stress biology and behavior.
- Shaping Social Networks: Institutions can influence the topography of social networks, thereby affecting experiences of social safety and threat. For example, historic exclusion based on demographics can lead to homophily in social networks, impacting the availability of social support.
- Stable Expectations: Institutions create stable expectations about behaviors, which can contribute to social safety (when expectations are positive) or social threat (e.g., systemic racism and discrimination). Higher-level sources of collective social threat can interact with acute and chronic individual stressors, either exacerbating or mitigating their effects.
- Prediction Errors: Mismatches between internalized models of expected behaviors (shaped by culture and institutions) and actual actions (e.g., during the COVID-19 pandemic) can contribute to feelings of social threat and allostatic load. This applies to processes like acculturation, where integrating into new cultural models can disrupt allostasis.
8. Explaining Health Disparities SST is particularly relevant for understanding the health and well-being of oppressed and marginalized populations who frequently experience discrimination, aggression, rejection, and exclusion.
- These experiences are forms of social threat that activate the Biobehavioral Response to Social Threat, leading to negative long-term health consequences.
- Racism, for instance, is deeply ingrained and significantly impacts mental and physical health in racially and ethnically diverse populations, increasing the risk of hypertension, cancer, obesity, and mental health problems. It also contributes to poorer access to quality healthcare.
- Discrimination based on gender and sexual orientation also leads to significant health disparities in sexually and gender diverse (SGD) populations. SST connects these minority stressors to health-damaging biological dynamics.
- Intersectionality is critical, as the influence of multiple intersecting identities (e.g., age, gender, sexual orientation, SES) on social interactions and environmental experiences complicates the impact of social threat on health. SST emphasizes investigating how these identities interact and influence experiences of social safety and threat at both micro and macro levels.
9. Protective Aspects of Social Safety A key contribution of SST is its framework for understanding not only why social threats are harmful but also why social safety appears to buffer the negative effects of social threats.
- The presence of social safety is hypothesized to downregulate SNS and HPA axis activity, thereby reducing inflammatory responses, which are key mechanisms underlying depression and physical health problems.
- This focus shifts research efforts beyond just disease biology to investigate biopsychosocial processes underlying desirable outcomes such as affiliation, affirmation, inclusion, belonging, meaning, and joy, providing an evidentiary base for salutogenesis and insights into resilience in marginalized groups.
10. Comparison with Related Perspectives SST builds upon and distinguishes itself from other frameworks:
- Attachment Theory: SST extends it by describing a complete set of biologically plausible mechanisms linking social experiences with health.
- Generalized Unsafety Theory (GUTS): SST posits that basal biological states are calibrated to the social environment, and threat-related biological processes are only activated for individuals with a history of social threat, contrasting with GUTS’s view of a default threat preparedness.
- Social Baseline Theory (SBT): While both value social bonds, SBT focuses on social relationships mitigating risk by preserving metabolic and neural resources, whereas SST emphasizes the reduction of physical injury/infection risk through social safety.
- Adaptive Calibration Model (ACM): SST includes social safety as a distinct resilience factor alongside threat, and describes a broader range of biological pathways beyond the HPA axis.
- Deprivation and Threat Model: SST conceptualizes social safety and social threat as separable, orthogonal dimensions, and adopts a life course perspective, while the deprivation and threat model focuses specifically on childhood adversity and physical harm.
11. Factors Affecting Social Safety and Threat (Moderators) SST identifies nine factors that can moderate the activity of social signal transduction pathways:
Situational Factors:
- Childhood Microbial Environment: Rural, microbially rich environments are hypothesized to lead to a more tightly controlled inflammatory response, potentially reducing the likelihood of social threats fostering chronic inflammation compared to sanitized urban environments.
- Birth Cohort: Influences social norms, experiences, institutions, and immunological/medical environments (e.g., changes in family structures, exposure to direct social/physical threats, public health improvements, vaccine availability).
- Culture: Cultural norms (e.g., stoicism, gender norms) can affect social networks, sources of social support, and biological outcomes (e.g., inflammation, blood pressure). Acculturation can also disrupt allostasis due to mismatches between cultural models and new environments.
- Air Pollution: Ambient air pollution (e.g., PM2.5) can directly affect the activity of social signal transduction pathways by inducing inflammatory events and has a greater mortality risk for low-SES and Black populations.
Individual Difference Factors:
- Genetics and Gene Expression: Genetic variations (SNPs) and epigenetic modifications can influence how social-environmental signals are converted into health- and behavior-altering biology. For example, certain IL6 gene variants can increase mortality risk from inflammation-related diseases under high social adversity, while others mitigate it. Similarly, OPRM1 gene variants can influence depressive reactions to social rejection. Socially safe environments are linked to less pro-inflammatory and more antiviral gene expression, while threatening environments show the opposite pattern.
- Sleep: Poor sleep is common in individuals exposed to social threats and can lead to decreased antiviral gene expression and increased pro-inflammatory gene expression, increasing risk for viral infections and inflammation-related morbidity. Social threats can disrupt sleep, and poor sleep can heighten neurobiological threat sensitivity, creating a bidirectional feedback loop.
- Diet: Diet impacts health through body composition (e.g., high-fat diets increasing adipose tissue and proinflammatory cytokines) and by modifying the gut microbiome. Inflammatory activity linked to diet can heighten perceived social threat, and perceived social safety can, in turn, influence eating behaviors (e.g., reducing opportunistic eating in unpredictable environments).
- Personality: Traits like extraversion are linked to greater social engagement, potentially leading to more social safety. Bidirectional relationships exist between personality traits (e.g., neuroticism, conscientiousness) and inflammatory processes, with inflammation potentially influencing personality and vice versa.
- Self-Harm (NSSI): Non-suicidal self-injury (NSSI) is linked to social threats like abuse. SST hypothesizes a bidirectional relationship where social threat may trigger NSSI, and NSSI (through tissue damage and DAMP release) may upregulate inflammatory activity, increasing perceived social threat and emotional distress, thus heightening the likelihood of further NSSI.
12. Measurement and Future Directions To empirically evaluate SST, it is crucial to develop and validate measures for social safety and threat across three key areas: perceptions, situational characteristics, and schemas. This will help disentangle their dynamic interplay and identify what drives downstream biological and health effects. Measures should be comprehensive, cover a breadth of beliefs and contexts, and consider developmental and cultural invariance. Longitudinal studies are essential to understand the temporal stability and malleability of social safety schemas and their co-creation with stress biology.
13. Interventions SST informs interventions at multiple levels of “social safety circles” (individual, family, school, community/society).
- Individual-level interventions can adapt existing therapies like Cognitive Behavioral Therapy (CBT) to specifically target social safety and threat-related cognitions and behaviors. This could involve helping individuals identify and modify core beliefs (e.g., “I’m unlovable”) and dysfunctional attitudes (e.g., “If I show my true self, I’ll get rejected”), and encouraging behaviors that foster social safety. Other individual-level approaches include Acceptance and Commitment Therapy, mindfulness, loving-kindness meditation, forgiveness therapy, self-distancing, and stress mindset interventions.
- Family-level interventions can include nurturant parenting and family cohesion training.
- School-level interventions focus on identity safety, social belonging, and mere belonging interventions to increase connection and reduce bullying.
- Community/society-level interventions aim to reduce bias, prevent bullying, promote social connection, and build empathy.
Ultimately, by understanding the evolutionary principles, dynamics, and pathways governing the social regulation of the human brain and immune system, SST aims to reveal the biopsychosocial roots of lifelong health disparities and identify new targets for interventions to reduce disease risk and achieve health equity.
APA Reference: Slavich, G. M., Roos, L. G., Mengelkoch, S., Webb, C. A., Shattuck, E. C., Moriarity, D. P., & Alley, J. C. (2023). Social Safety Theory: Conceptual foundation, underlying mechanisms, and future directions. Health Psychology Review, 17(1), 5–59. https://doi.org/10.1080/17437199.2023.2171900
