Current debates concerning the use of digital technology often focus on privacy, yet privacy attitudes and behavior are remarkably under-theorized, and relatively little empirical research has investigated privacy beyond the realm of digital communications. Building on evolutionary scholarship on information exchange, we outline a theoretical model in which cultural concepts of privacy reflect the workings of evolved psychological mechanisms that aim to regulate others’ access to fitness-relevant information towards adaptive ends. Results of two initial U.S. vignette studies distributed via Prolific (n=425, 120) support the core predictions of this model, suggesting that people may have implicit and unstated assumptions regarding how information spreads in social environments. Specifically, participants’ privacy evaluations were predicted by whether information was intentionally acquired, the extent to which information was transmitted, and an individual’s position in an information transfer event. Importantly, how information was acquired and the nature of its transmission constituted independent but interacting influences on privacy perceptions. Additionally, results suggest the location within shared social networks of the individual to whom information is transmitted is used as a proxy for the potential costs of dissemination.

This article analyzes the evolutionary genesis of the aldehyde dehydrogenase 2 (ALDH2) mutation in East Asia through the lenses of institutional economics and systems sociology. While biology typically frames the absence of alcohol tolerance as a metabolic defect, this paper proposes the concept of functional redundancy. We argue that the specific social organization of rice societies—characterized by deep material interdependence—rendered alcohol consumption superfluous as an instrument for trust-building and social cohesion. The resulting genetic path dependency illustrates how historical institutional frameworks continue to shape the biological constitution of modern populations.

The menopausal transition is a pivotal period in the female reproductive lifespan with potential consequences for long-term health and quality of life. Latine adults in the US often experience menopause earlier and have more frequent vasomotor symptoms (VMS) compared to non-Latine White adults. These differences may be partly attributed to early life adversity, such as adverse childhood experiences (ACEs), which may alter energy allocation towards faster maturation and reproductive efforts, potentially shaping variations in menopausal experiences. Using data from a sample of primarily immigrant, Mexican adults living in an agricultural region in California (N=459), we evaluated the extent to which ACEs were associated with age at menopause and VMS (hot flashes and night sweats). In adjusted models, having ACEs (vs. none) was significantly associated with experiencing hot flashes (1–3 ACEs: OR = 2.50, 95% CI: 1.57 – 4.00; 4+ ACEs: OR = 2.51, 95% CI: 1.49 – 4.24) and night sweats (1–3 ACEs: OR = 1.67, 95% CI: 1.02 – 2.76; 4+ ACEs: OR = 2.36, 95% CI: 1.37 – 4.06) but not earlier menopause (e.g., 1–3 ACEs: HR = 0.85, 95% CI: 0.59 – 1.21). These results suggest that the sequelae of childhood adversity may influence menopausal symptom burden.

Individual social identities indicate group affiliations and are typically associated with group-typical preferences, signals that indicate group membership, and the propensity to condition actions on the social signals of others, resulting in group-differentiated interaction norms. Past work modeling identity signaling and coordination has typically assumed that individuals belong to one of a discrete set of groups. Yet individuals can simultaneously belong to multiple groups, which may be nested within larger groupings. Here, we introduce the generalized Bach or Stravinsky game, a coordination game with ordered preferences, which allows us to construct a model that captures the overlapping and hierarchical nature of social identity. Our model unifies several prior results into a single framework, including results related to coordination, minority disadvantage, and cross-cultural competence. Our model also allows agents to express complex social identities through multidimensional signaling, which we use to explore a variety of complex group structures. Our consideration of intersectional identities exposes flaws in naive measures of group structure, illustrating how empirical studies may overlook some social identities if they do not consider the behaviors that those identities function to afford.

Life history theory seeks to understand how organisms distribute energy between physiological functions across the life course. A central assumption is that energy allocation involves “trade-offs” between competing functions relating to defence, maintenance, reproduction and growth. Constraints on human energy expenditure may produce trade-offs during energetic stress, affecting functions critical for homeostasis, survival and reproduction. While there is some evidence for binary trade-offs between two functions in humans, no studies have tested physiological resource prioritisation across multiple functions under energetic constraint. This study empirically assessed multiple human life history trade-offs and the proximate biological mechanisms underpinning them. We recruited 147 ultra-endurance athletes (107 male, 40 female) participating in four environmentally diverse multiday ultramarathons and one multiweek ocean rowing event. The severe energetic demands of these competitions provide a valuable opportunity to provoke and observe detectable trade-offs. We found evidence of trade-offs across multiple functions. Specifically, investment in (as indexed by immune biomarkers) was broadly prioritised relative to investment in storage, reproduction and maintenance. Our results enhance current understanding of the role of phenotypic plasticity in human adaptability and have implications for athlete health and performance as well as the emerging discipline of evolutionary public health.

Two research branches in evolutionary psychology can make similar predictions about treatment expectations in contexts of conflict of interest, where, for those involved, costs and benefits are at stake. Recalibrational Theory of Anger suggests that evolved psychological mechanisms operate at the cognitive level and regulate human behavior. The Dark Triad Personality posits that traits of Machiavellianism, Narcissism, and Psychopathy confer adaptive advantages, leading individuals to prioritize their interests over those of others. This study aimed to replicate the results of Sell et al. (2017) in a Brazilian sample (Replication Analysis) and investigated whether dark triad traits predict the magnitude of anger in conflict-of-interest situations (Extension Analysis). Replication Analysis consistently replicated previous findings, with effect sizes from moderate to large magnitudes. Extension Analysis revealed that only Narcissism was a significant predictor when victims were intentionally targeted by offenders. While the Recalibrational Theory of Anger predictions were largely confirmed, the dark triad personality traits, except for Narcissism, were generally poor predictors of anger magnitude. The results suggest that the universality of the information processing is robust and is little influenced by antisocial personality characteristics.