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Phylogeny of nine imaginary cultures constructed from the degree of cultural similarity that is due to common descent; * = independent origin of camel use; yes = camel use, no = no camel use
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Comparative methodology is controversial in biology and the related field of research on behavioral and psychological traits across human cultures. We critically examine this controversy. We argue that the widely held opinion of non-independence among historically-related cultures and species errs by not recognizing and incorporating into research...
Citations
... Estimating the covariance due to proximity and relationships allows the data to speak: if patterns of variation do not correspond to proximity or relationships then the covariance matrices due to phylogeny and distribution will not influence the analysis. It is not necessary to assume, a priori, either that cultures represent independent data points due to separate instances of adaptation to shared environmental conditions (Thornhill and Fincher 2013), or that observations are confounded by non-independence due to descent or shared environment. The need to incorporate information on relatedness and proximity does not need to be settled by argument alone, but by testing for evidence of spatial autocorrelation (e.g. ...
Many important and interesting hypotheses about cultural evolution are evaluated using cross-cultural correlations: if knowing one particular feature of a culture (e.g. environmental conditions such as temperature, humidity or parasite load) allows you to predict other features (e.g. language features, religious beliefs, cuisine), it is often interpreted as indicating a causal link between the two (e.g. hotter climates carry greater disease risk which encourages belief in supernatural forces and favours use of antimicrobial ingredients in food preparation; dry climates make production of distinct tones more difficult). But testing such hypotheses from cross-cultural comparisons requires us to take proximity of cultures into account: nearby cultures share many aspects of their environment and are more likely to be similar in many culturally-inherited traits. This can generate indirect associations between environment and culture which could be misinterpreted as signal of a direct causal link. Evaluating examples of cross-cultural correlations from the literature, we show that significant correlations interpreted as causal relationships can often be explained as a result of similarity between neighbouring cultures. We discuss some strategies for sorting the explanatory wheat from the co-varying chaff, distinguishing incidental correlations from causal relationships.
... On the other side of Galton's problem controversy, some argue that "phylogenetic correction" (i.e., treating nations as non-independent) is not a method that should be applied to all comparative studies (Westoby et al., 1995). Phylogenetic correction is necessary when the question under investigation is phylogenetic creation of a cultural trait, but it is irrelevant for comparative analysis of persistence of cultural items (Thornhill & Fincher, 2013). ...
Among four proposed origins of individualism-collectivism, modernization theory, rice versus wheat theory, climato-economic theory, and pathogen stress theory, the latter has gained more attention in cross-cultural and evolutionary psychology. Since the parasite stress theory of values and sociality makes a connection between infectious diseases and cultural orientations, it gained even more popularity during the COVID pandemic. But despite extensive research on parasite stress theory, it is not still clear what kind of infectious disease contributes more to the emergence of cultures, what are the possible mechanisms through which pathogenic threat gives rise to cultural systems, and how parasite stress might affect vertical vs. horizontal dimensions of individualism-collectivism. This review summarizes and integrates major findings of parasite stress theory related to individualism-collectivism and its closely related variables and discusses future directions that researchers can take to answer the remaining questions.
... Al tener un rol central en la teorización, el método comparativo es fundamental para la AE. Como tal, ha permitido estudiar tópicos como cognición, diversidad cultural, primatología o genética poblacional; razón por la cual es catalogada como "la piedra angular de los esfuerzos por entender la diversidad biológica y cultural" (Nunn, 2011, p.1). Por su utilidad para testear y generar hipótesis, ha sido empleada en estudios transculturales y transespecie, usuales en biología evolucionista (Thornhill y Fincher, 2013). Dicho esto, la THD constituye una teoría hipotéticodeductiva por los siguientes motivos: a) Por basarse en un marco teórico. ...
"Usualmente, la antropología es considerada una ciencia "blanda" y algunas veces ni siquiera una ciencia. Desde esta perspectiva, se ha dicho que es incapaz de crear teorías científicas como lo hacen las ciencias naturales o básicas. Tal estado de cosas se ha establecido en la literatura reciente, generando una imagen limitada de la disciplina. Mediante un análisis del problema de la inducción, el presente ensayo demuestra que la antropología es capaz de formular rigurosas teorías científicas. Para ello, se exploran las funciones y objetivos del concepto de teoría; se analiza el impacto del problema de la inducción en epistemología y antropología; y se establece cómo una reciente propuesta antropológica-teoría de la herencia dual-constituye un ejemplo de teoría científica deductiva. Finalmente, se esbozan algunas conclusiones sobre la capacidad teórica de la antropología. La finalidad de este ensayo es determinar que, combinando razonamientos inductivos y deductivos, la antropología es capaz de formular teorías científicas tan rigurosas como aquellas realizadas en las ciencias "duras"."
"Anthropology is usually considered a "soft" science and sometimes not even a science. From this perspective, it has been said that it is incapable of creating theories as the natural or basic sciences do. Such state of affairs has been established in recent literature, generating a limited image of the discipline. Through an analysis of the problem of induction, this essay shows that anthropology is capable of formulating rigorous scientific theories. For this, the functions and objectives of the concept of theory are explored; the impact of the problem of induction in epistemology and anthropology is analyzed; and it is established how a recent anthropological proposal-dual inheritance theory-constitutes an example of a deductive scientific theory. Finally, some conclusions are outlined on the theoretical capacity of anthropology. The purpose of this essay is to determine that, combining inductive and deductive reasoning, anthropology is capable of formulating scientific theories as rigorous as those carried out in the "hard" sciences."
... This suggests that: (a) neither phylogenetic inertia (Huber, 1939; but see Shanahan, 2011) nor "Isolation by Distance" (Ishida, 2009; but see Slatkin, 1993) among the contiguous areas that were colonized successively by human "Out of Africa" migrations were sufficient to account for our reported pattern of results in human life history biodiversity, and (b) the preponderance of the variance among contemporary national polities is instead best explained by divergent evolution produced as a result of differential ecological selective pressures among zoogeographical regions. It should be noted, however, that Thornhill and Fincher (2013) have argued quite con-vincingly that, as contiguous geographic areas tend to be similar in ecology, such statistical adjustments might inadvertently absorb the effects of current continuities in evolutionarily relevant ecological parameters among adjacent ecosystems. Spatial contiguity might thus produce similarities among adjacent populations that are attributable to current adaptations to similar environments by means of continuing selection, thus statistically adjusting for spatial autocorrelations might inappropriately attenuate our estimates of the magnitude of the effects of ecological selective pressures. ...
Controversial theories have been advanced (e.g., Rushton, 1985, 2000) relating “race” to human life history strategy: (a) different human populations (“races”) evolved in different physical and community ecologies; (b) these ecologies should at least partially determine the selective pressures shaping the evolution of human life history strategies in different parts of the world; ergo (c) different human populations (“races”) should be associated with different modal life history strategies. Although the argument seems plausible in its stark logical form, there were several limitations in operationalization: (a) the traditional “Big Three Races” used (Caucasoid, Mongoloid, and Negroid) do not correspond very closely to the five or six major population clusters identified by modern human genetics; (b) these “races” are neither discrete nor mutually exclusive, having many zones of overlap and interbreeding, making geographical boundaries fuzzy and imprecise; (c) fixing the “race” issue will still not directly address the fundamental premise of the theory that human life history strategy is largely determined by ecological factors. We therefore divided a sample of 141 national polities into zoogeographical regions instead of conventionally defined “races.” We only used regions for this analysis that were still inhabited mostly by the aboriginal populations that existed there prior to the 15th century AD. Although obtained by different procedures than those used originally by Rushton, these produced results that were surprisingly convergent with the basic premise underlying the original hypotheses.
... Work on ecological pathogen prevalence and cultural psychological variation has generated considerable discussion (e.g., Hruschka & Hackman, 2014;Pollet, Tybur, Frankenhuis, & Rickard, 2014;Thornhill & Fincher, 2013), much of which revolves around issues of how cross-cultural associations should be interpreted, the methodological difficulties that emerge, and alternative explanations. It is nevertheless important to note that even where alternative explanations for a proposed ecological effect might exist, the alternative is often likely to remain an ecological hypothesis of some form (Nettle, 2009). ...
Recent work has documented a wide range of important psychological differences across societies. Multiple explanations have been offered for why such differences exist, including historical philosophies, subsistence methods, social mobility, social class, climactic stresses, and religion. With the growing body of theory and data, there is an emerging need for an organizing framework. We propose here that a behavioral ecological perspective, particularly the idea of adaptive phenotypic plasticity, can provide an overarching framework for thinking about psychological variation across cultures and societies. We focus on how societies vary as a function of six important ecological dimensions: density, relatedness, sex ratio, mortality likelihood, resources, and disease. This framework can: (1) highlight new areas of research, (2) integrate and ground existing cultural psychological explanations, (3) integrate research on variation across human societies with research on parallel variations in other animal species, (4) provide a way for thinking about multiple levels of culture and cultural change, and (5) facilitate the creation of an ecological taxonomy of societies, from which one can derive specific predictions about cultural differences and similarities. Finally, we discuss the relationships between the current framework and existing perspectives.
... Finally, some have noted that using nations as units of analysis violates the assumption of independence (i.e., Galton's problem), as geographically adjacent countries may share a variety of similarities with one another (Pollet, Tybur, Frankenhuis, & Rickard, 2014). Others have argued against this as a problem (Thornhill & Fincher, 2013). We note first that this is a complex issue for which there seems no clear consensus on any single solution. ...
A new theoretical tool called life history theory offers an answer
... In the cases with Table S3). 320 It could be argued that it is legitimate to consider particular asexual monophyletic 321 lineages in the polyphyletic AA group as independent observations when we inquire into the 322 reasons for maintaining sexual reproduction, not into the reasons for the transition to sexuality 323 (Thornhill & Fincher, 2013). However, we chose the more conservative approach because, as Table S3). ...
Ecological theories of sexual reproduction assume that sexuality is advantageous in certain conditions, for example, in biotically or abiotically more heterogeneous environments. Such theories thus could be tested by comparative studies. However, the published results of these studies are rather unconvincing. Here we present the results of a new comparative study based solely on the ancient asexual clades. The association with biotically or abiotically homogeneous environments in these asexual clades was compared with the same association in their sister, or closely related, sexual clades. Using the conservative definition of ancient asexuals (i.e. age > 1 million years), we found six pairs for which relevant ecological data are available. The difference between the homogeneity type of environment associated with the sexual and asexual species was then compared in an exact binomial test. Based on available literature, the results showed that the vast majority of ancient asexual clades tend to be associated with biotically or abiotically, biotically, and abiotically more homogeneous environments than their sexual controls. In the exploratory part of the study, we found that the ancient asexuals often have durable resting stages, enabling life in subjectively homogeneous environments, live in the absence of intense biotic interactions, and are very often sedentary, inhabiting benthos and soil. The consequences of these findings for the ecological theories of sexual reproduction are discussed.
... Finally, some have noted that using nations as units of analysis violates the assumption of independence (i.e., Galton's problem), as geographically adjacent countries may share a variety of similarities with one another (Pollet, Tybur, Frankenhuis, & Rickard, 2014). Others have argued against this as a problem (Thornhill & Fincher, 2013). We note first that this is a complex issue for which there seems no clear consensus on any single solution. ...
The world population has doubled over the last half century. Yet, research on the psychological effects of human population density, once a popular topic, has decreased over the past few decades. Applying a fresh perspective to an old topic, we draw upon life history theory to examine the effects of population density. Across nations and across the U.S. states (Studies 1 and 2), we find that dense populations exhibit behaviors corresponding to a slower life history strategy, including greater future-orientation, greater investment in education, more long-term mating orientation, later marriage age, lower fertility, and greater parental investment. In Studies 3 and 4, experimentally manipulating perceptions of high density led individuals to become more future-oriented. Finally, in Studies 5 and 6, experimentally manipulating perceptions of high density seemed to lead to life-stage-specific slower strategies, with college students preferring to invest in fewer rather than more relationship partners, and an older MTurk sample preferring to invest in fewer rather than more children. This research sheds new insight on the effects of density and its implications for human cultural variation and society at large. (PsycINFO Database Record
... The latter results from the nonindependence of variables sampled in spatial or temporal proximity to one another (e.g. Mace & Pagal, 1994; for detailed criticisms of the concept as commonly, and naively applied in cross-cultural research see: Thornhill & Fincher, 2013). Autocorrelation is considered problematic because non-independence among supposedly spatially discrete variables violates the assumption of independently and identically distributed errors, hence leads to false positive (Type I) errors. ...
... The latter results from the nonindependence of variables sampled in spatial or temporal proximity to one another (e.g. Mace & Pagal, 1994; for detailed criticisms of the concept as commonly, and naively applied in cross-cultural research see: Thornhill & Fincher, 2013). Autocorrelation is considered problematic because non-independence among supposedly spatially discrete variables violates the assumption of independently and identically distributed errors, hence leads to false positive (Type I) errors. ...
