Fincher & Thornhill (F&T) present a compelling argument that parasite stress underlies certain cultural practices promoting assortative sociality. However, we suggest that the theoretical framework proposed is limited in several ways, and that life history theory provides a more explanatory and inclusive framework, making more specific predictions about the trade-offs faced by organisms in the allocation of bioenergetic and material resources.

In this article we attend to recent critiques of psychometric applications of life history theory to variance among humans and develop theory to advance the study of latent LH constructs. We then reanalyze data previously examined by Richardson et al., 2017, https://doi.org/10.1177/1474704916666840 to determine whether previously reported evidence of multidimensionality is robust to the modeling approach employed and the structure of LH indicators is invariant by sex. Findings provide further evidence that a single LH dimension is implausible and that researchers (...) should cease interpreting K-factor scores as empirical proxies for LH speed. In contrast to the original study, we detected a small inverse correlation between mating competition and Super-K that is consistent with a trade-off. Tests of measurement invariance across the sexes revealed evidence of metric invariance, consistent with the theory that K is a proximate cause of its indicators; however, evidence of partial scalar invariance suggests use of scores likely introduces bias when the sexes are compared. We discuss limitations and identify approaches that researchers may use to further evaluate the validity of the K-factor and other applications of LH to human variation. (shrink)

The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These (...) predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood. (shrink)

Fincher & Thornhill's (F&T's) parasite-stress theory of sociality is supported largely by correlational evidence; its persuasiveness would increase significantly via lab and natural experiments and demonstrations of its mediating role. How the theory is linked to other approaches to group differences in psychological differences and to production and dissemination of cultural ideas and practices, need further clarification. So does the theory's view on the possible reduction of negative group interactions.

Utilizing an evolutionary perspective has proven fruitful in a number of areas of interest outside of the standard psychological or anthropological topics. This includes a wide range of fields from applied disciplines such as law, criminology, medicine, and marketing, to the study of the imagined worlds found in art and literature, the domains of the humanities. A number of excellent books, as well as numerous articles, detail the impressive work done in applying evolutionary insights to the study of art and (...) literature. This article focuses on evolutionarily informed explorations of popular culture, an area that, only relatively recently, has benefited from research taking this approach. The existing scholarship in this area will be reviewed, and future directions and challenges highlighted. (shrink)

The fast–slow paradigm of life history focuses on how individuals grow, mate, and reproduce at different paces. This paradigm can contribute substantially to the field of personality and individual differences provided that it is more strictly based on evolutionary biology than it has been so far. Our study tested the existence of a fast–slow continuum underlying indicators of reproductive effort—offspring output, age at first reproduction, number and stability of sexual partners—in 1,043 outpatients with healthy to severely disordered personalities. Two axes (...) emerged reflecting a double-track pathway to fast strategy, based on restricted and unrestricted sociosexual strategies. When rotated, the fast–slow and sociosexuality axes turned out to be independent. Contrary to expectations, neither somatic effort—investment in status, material resources, social capital, and maintenance/survival—was aligned with reproductive effort, nor a clear tradeoff between current and future reproduction was evident. Finally, we examined the association of LH axes with seven high-order personality pathology traits: negative emotionality, impulsivity, antagonism, persistence-compulsivity, subordination, and psychoticism. Persistent and disinhibited subjects appeared as fast-restricted and fast-unrestricted strategists, respectively, whereas asocial subjects were slow strategists. Associations of LH traits with each other and with personality are far more complex than usually assumed in evolutionary psychology. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Human Nature in Nineteenth-Century British Novels:Doing the MathJoseph Carroll, Jonathan Gottschall, John A. Johnson, and Daniel J. KrugerIThree broad ambitions animate this study. Building on research in evolutionary social science, we aimed (1) to construct a model of human nature—of motives, emotions, features of personality, and preferences in marital partners; (2) use that model to analyze some specific body of literary texts and the responses of readers to those (...) texts, and (3) produce data—information that could be quantified and could serve to test specific hypotheses about those texts.Evolutionary social science is still in the process of constructing a full and adequate model of human nature. Evolutionary social scientists know much already about how human reproductive behavior and human sociality fit into the larger pattern of human evolution. They still have much to learn, though, about the ways literature and the other arts enter into human nature. Our model of human nature draws on our knowledge of imaginative culture, integrates that knowledge with evolutionary theories of culture, and produces data that enable us to draw conclusions on an issue of broad significance for both literary study and evolutionary social science: the adaptive function of literature and the other arts.1In order to make advances in knowledge, it is necessary to choose some particular subject. Genetics is a basic science that applies to all organisms, but geneticists first got an empirical fix on their subject by focusing minutely, with Mendel, on peas, and, with Morgan, on fruit flies. In place of peas and flies, we have taken as our subject British novels of [End Page 50] the longer nineteenth century (Austen to Forster). As a literary topic, the subject is fairly broad, but our theoretical and methodological aims ultimately extend well beyond the specialist fields of British novels, the nineteenth century, British literature, narrative fiction, or even literary scholarship generally. This study is designed to engage the attention of literary scholars in all fields and also to engage the attention of social scientists. If it achieves its aims, this study would help persuade literary scholars that empirical methods offer rich opportunities for the advancement of knowledge about literature, and it would help persuade social scientists that the quantitative study of literature can shed important light on fundamental questions of human psychology and human social interaction. Our own research team combines these two prospective audiences. Two of us (Carroll and Gottschall) have been trained primarily as literary scholars, and two of us (Johnson and Kruger) primarily as social scientists.The focal point for this study is "agonistic" structure: the organization of characters into protagonists, antagonists, and minor characters. The central question in the study is this: does agonistic structure reflect evolved dispositions for forming cooperative social groups? Suppressing or muting competition within a social group enhances group solidarity and organizes the group psychologically for cooperative endeavor. Our chief hypothesis was that protagonists and good minor characters would form communities of cooperative endeavor and that antagonists would exemplify dominance behavior. If this hypothesis proved correct, the ethos reflected in the agonistic structure of the novels would replicate the egalitarian ethos of hunter-gatherers, who stigmatize and suppress status-seeking in potentially dominant individuals. If suppressing dominance in hunter-gatherers fulfills an adaptive social function, and if agonistic structure in the novels engages the same social dispositions that animate hunter-gatherers, our study would lend support to the hypothesis that literature fulfills an adaptive social function.2One of our chief working hypotheses is that when readers respond to characters in novels, they respond in much the same way, emotionally, as they respond to people in everyday life. They like or dislike them, admire them or despise them, fear them, feel sorry for them, or are amused by them. In writing fabricated accounts of human behavior, novelists select and organize their material for the purpose of generating such responses, and readers willingly cooperate with this purpose. They participate vicariously in the experiences depicted and form personal opinions about the qualities of the characters. Authors and readers [End Page 51] thus collaborate in producing a simulated experience of emotionally responsive evaluative judgment. If agonistic structure is a... (shrink)

Within evolutionary biology, life-history theory is used to explain cross-species differences in allocation strategies regarding reproduction, maturation, and survival. Behavioral scientists have recently begun to conceptualize such strategies as a within-species individual characteristic that is predictive of behavior. Although life history theory provides an important framework for behavioral scientists, the psychometric approach to life-history strategy measurement—as operationalized by K-factors—involves conceptual entanglements. We argue that current psychometric approaches attempting to identify K-factors are based on an unwarranted conflation of functional descriptions and (...) proximate mechanisms—a conceptual mix-up that may generate unviable hypotheses and invites misinterpretation of empirical findings. The assumptions underlying generic psychometric methodology do not allow measurement of functionally defined variables; rather these methods are confined to Mayr’s proximate causal realm. We therefore conclude that K-factor scales lack validity, and that life history strategy cannot be identified with psychometrics as usual. To align theory with methodology, suggestions for alternative methods and new avenues are proposed. (shrink)

The current research applied a mid-level evolutionary theory that has been successfully employed across numerous animal species—life history theory—in an attempt to understand the Dark Triad personality trait cluster (narcissism, psychopathy, and Machiavellianism). In Study 1 (N = 246), a measure of life history strategy was correlated with psychopathy, but unexpectedly with neither Machiavellianism nor narcissism. Study 2 (N = 321) replicated this overall pattern of results using longer, traditional measures of the Dark Triad traits and alternative, future-discounting indicators of (...) life history strategy (a smaller-sooner, larger-later monetary dilemma and self-reported risk-taking behaviors). Additional findings suggested two sources of shared variance across the Dark Triad traits: confidence in predicting future outcomes and openness to short-term mating. (shrink)

In evolutionary psychology, it is customary to measure life-history via psychometric inventories such as the Arizona Life History Battery. The validity of this approach has been questioned: it is argued that these measures are not congruent with biological life history events, such as the number of children, age at first birth, or pubertal timing. However, empirical data to test this critique are lacking. We therefore administered the ALHB to a convenience sample of young adults in Serbia. We also collected information (...) on psychosocial-biodemographic life history parameters closely related to biological life history traits: pubertal timing, onset of sexual behavior, short- and long-term mating, number of children, timing of reproduction, parenthood values, and environmental harshness. We found that correlations between these two sets of measures were rare, unsystematic, and mostly low in magnitude. Stable patterns of relations emerged only between the indicators of environmental conditions from both sets of measures. Furthermore, some ALHB indicators were found to be positively related with early fertility, which is incongruent with the conceptual foundation of ALHB. Finally, network analysis and factor analysis within each set of measures revealed different structures and that the hypothesis of unidimensionality, on which the ALHB was founded, cannot be applied to psychosocial-biodemographic life history indicators. Our results support the critique of ALHB as a set of measures lacking validity to capture biodemographic life-history parameters. ALHB measures are indeed relevant for understanding life-history variation, but they cannot be used as a substitute for specific life history characteristics. Our findings are a warning to researchers to use direct measures of biological events in order to measure life-history dynamics. (shrink)

The Continuous Parameter Estimation Model is applied to develop individual genomic-level heritabilities for the latent hierarchical structure and developmental dynamics of Life History (LH) strategy LH strategies relate to the allocations of bioenergetic resources into different domains of fitness. LH has moderate to high population-level heritability in humans, both at the level of the high-order Super-K Factor and the lower-order factors, the K-Factor, Covitality Factor, and General Factor of Personality (GFP). Several important questions remain unexplored. We developed measures of genome-level (...) heritabilities employing an American sample of 316 monozygotic (MZ) and 274 dizygotic (DZ) twin dyads and a Swedish sample of 863 MZ and 475 DZ twin dyads. This novel heritability index measures individual genetic transmissibility, therefore opening new avenues for analyzing complex interactions among heritable traits inaccessible to standard structural equations methods. For these samples: (1) moderate to high heritability of factor loadings of Super-K on its lower-order factors is demonstrated, evidencing biological preparedness, genetic accommodation, and the gene-culture coevolution of biased epigenetic rules of development; (2) moderate to high heritability of the magnitudes of the effect of the higher-order factors upon their loadings on their constituent factors, evidencing genetic constraints upon phenotypic plasticity; and (3) that heritability of the LH factors, of factor loadings, and of the magnitudes of the correlations among factors are weaker among those with slower LH speeds, demonstrating that inter-individual variation in transmissibility is a function of individual socioecological selection pressures. (shrink)

A high risk of morbidity-mortality caused by a harsh and unpredictable environment is considered to be associated with a fast life history strategy, commonly linked with criminal behavior. However, offenders are not the only group with a high exposure to extrinsic morbidity-mortality. In the present study, we investigated the LH strategies employed by two groups of Polish men: incarcerated offenders as well as soldiers and firefighters, whose professions involve an elevated risk of injury and premature death. The subjects were asked (...) to complete the Mini-K and a questionnaire which included a number of biodemographic LH variables. Although biodemographic and psychosocial LH indicators should be closely linked with each other, the actual connection between them is unclear. Thus, this study was driven by two aims: comparing LH strategies in two groups of men with a high risk of premature morbidity-mortality and investigating the relationship between the biodemographic and psychosocial LH dimensions. The study showed that incarcerated men employed faster LH strategies than soldiers and firefighters, but only in relation to biodemographic variables. No intergroup differences emerged regarding psychosocial LH indicators. Moreover, the correlation analysis showed a weak association between biodemographic and psychosocial LH indicators. The results strengthen the legitimacy of incorporating biodemographic LH traits into research models and indicate the need for further research on the accuracy of the Mini-K. The possible explanations for the intergroup differences in LH strategies are discussed. (shrink)

A secondary analysis was performed on preliminary data from an ongoing cross-cultural study on assortative pairing. Independently sampled pairs of opposite-sex romantic partners and of same-sex friends rated themselves and each other on Life History (LH) strategy and mate value. Data were collected in local bars, clubs, coffeehouses, and other public places from three different cultures: Tucson, Arizona; Hermosillo, Sonora; and San José, Costa Rica. The present analysis found that slow LH individuals assortatively pair with both sexual and social partners (...) more strongly than fast LH individuals. We interpret this phenomenon as representing (1) an adaptation for preserving coadapted genomes in slow LH strategists to maintain high copying fidelity genetic replication while producing a lower number of offspring in stable, predictable, and controllable environments and (2) a bet-hedging adaptation in fast LH strategists, favoring the genetic diversification of a higher number of offspring in unstable, unpredictable, and uncontrollable environments. (shrink)

Bedtime procrastination is generally considered to be a maladaptive behavior. However, BP may be an adaptive fast LH strategy within the LH framework, and further, personal beliefs about their abilities and resources promote this fast LH strategy. Here, the present study addressed this idea, focusing on the effect of self-efficacy on BP, the mediation of harm avoidance, and the moderation of novelty seeking. Data from 552 Chinese university students were analyzed using SPSS 25.0 and SPSS PROCESS Macro. Results indicated that (...) HA partially mediates the relationship between self-efficacy and BP. Main interactional effects have been observed when NS is introduced in the model as a moderator. Implications and limitations of the study and suggestions for further study are discussed. (shrink)

Life history theory is a fruitful source of testable hypotheses about human individual differences. However, this field of study is beset by unresolved debates about basic concepts and methods. One of these controversies concerns the usefulness of instruments that purport to tap a unidimensional life history factor based on a set of self-reported personality, social, and attitudinal variables. Here, we take a novel approach to analyzing the psychometrics of two variants of the Arizona Life History Battery: the Mini-K and the (...) K-SF-42. Psychological network analysis generates models in which psychological variables comprise the nodes of a network, while partial correlation coefficients between these variables comprise the edges of the network. Centrality indices operationalize each node’s importance based on the pattern of the connections in which that node plays a role. Because childhood environments are hypothesized to influence adult LH, we tested the hypothesis that among the Mini-K items, and the K-SF-42 scales, those that tap relationships with parents are central to the networks constructed from these instruments. In an MTurk sample and an undergraduate sample that completed the Mini-K, and an MTurk sample that completed the K-SF-42, this hypothesis was falsified. Indeed, the “relationships with parents” items were among the most peripheral in all three networks. We propose that network analysis, as an alternative to latent variable modeling, offers considerable potential to test hypotheses about the input-output mappings of specific evolved psychological mechanisms. (shrink)