Heitor B. F. Fernandes

Methodologically Sound: Evaluating the Psychometric Approach to the Assessment of Human Life History [Reply to Copping, Campbell, and Muncer, 2014]

Copping, Campbell, and Muncer (2014) have recently published an article critical of the psychometric approach to the assessment of life history (LH) strategy. Their purported goal was testing for the convergent validation and examining the psychometric structure of the High-K Strategy Scale (HKSS). As much of the literature on the psychometrics of human LH during the past decade or so has emanated from our research laboratory and those of close collaborators, we have prepared this detailed response. Our response is organized into four main sections: (1) A review of psychometric methods for the assessment of human LH strategy, expounding upon the essence of our approach; (2) our theoretical/conceptual concerns regarding the critique, addressing the broader issues raised by the critique regarding the latent and hierarchical structure of LH strategy; (3) our statistical/methodological concerns regarding the critique, examining the validity and persuasiveness of the empirical case made specifically against the HKSS; and (4) our recommendations for future research that we think might be helpful in closing the gap between the psychometric and biometric approaches to measurement in this area. Clearly stating our theoretical positions, describing our existing body of work, and acknowledging their limitations should assist future researchers in planning and implementing more informed and prudent empirical research that will synthesize the psychometric approach to the assessment of LH strategy with complementary methods.

By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century

It has been theorized that declines in general intelligence (g) due to genetic selection stemming from the inverse association between completed fertility and IQ and the Flynn effect co-occur, with the effects of the latter being concentrated on less heritable non-g sources of intelligence variance. Evidence for this comes from the observation that 19th century populations were more intellectually productive, and also exhibited faster simple reaction times than modern ones, suggesting greater information-processing ability and therefore higher g. This co-occurrence model is tested via examination of historical changes in the utilization frequencies of words from the highly g-loaded WORDSUM test across 5.9 million texts spanning the period 1850–2005. Consistent with predictions, words with higher difficulties (δ parameters from Item Response Theory) and stronger negative correlations between pass rates and completed fertility declined in use over time whereas less difficult and less strongly selected words, increased in use over time, consistent with a Flynn effect stemming in part from the vocabulary enriching effects of increases in population literacy. These findings persisted when explicitly controlled for word age, changing literacy rates and temporal autocorrelation. These trends constitute compelling evidence for the co-occurrence model.

The more g-loaded, the more heritable, evolvable, and phenotypically variable: Homology with humans in chimpanzee cognitive abilities

Expanding on a recent study that identified a heritable general intelligence factor (g) among individual chimpanzees from a battery of cognitive tasks, we hypothesized that the cognitive abilities that are more g-loaded would be more heritable and would present more additive genetic variance, in addition to showing more phenotypic variability. This pattern was confirmed, and is comparable to that found in humans, indicating fundamental homology. Finally, tool use presented the highest heritability, the largest amount of additive genetic variance and of phenotypic variance, consistent with previous findings indicating that it is associated with high interspecies variance and evolutionary rates in comparative primate studies.

Strategic differentiation and integration of genomic-level heritabilities facilitate individual differences in preparedness and plasticity of human life history

Life history (LH) strategies refer to the pattern of allocations of bioenergetic and material resources into different domains of fitness. While LH is known to have moderate to high population-level heritability in humans, both at the level of the high-order factor (Super-K) and the lower-order factors (K, Covitality, and the General Factor of Personality), several important questions remain unexplored. Here, we apply the Continuous Parameter Estimation Model to measure individual genomic-level heritabilities (termed transmissibilities). These transmissibility values were computed for the latent hierarchical structure and developmental dynamics of LH strategy, and demonstrate; (1) moderate to high heritability of factor loadings of Super-K on its lower-order factors, 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, their factor loadings, and the magnitudes of the correlations among factors, are weaker among individuals with slower LH speeds. The results were obtained from 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, and indicate that inter-individual variation in transmissibility is a function of individual socioecological selection pressures. Our novel technique, opens new avenues for analyzing complex interactions among heritable traits inaccessible to standard structural equation methods.

What Causes the Anti-Flynn Effect? A Data Synthesis and Analysis of Predictors.

Anti-Flynn effects (i.e., secular declines in IQ) have been noted in a few countries. Much speculation exists about the causes of these trends; however, little progress has been made toward comprehensively testing these. A synthetic literature search yielded a total of 66 observations of secular IQ decline from 13 countries, with a combined sample size of 302,234 and study midyears spanning 87 years, from 1920.5 to 2007.5. Multilevel modeling (MLM) was used to examine the effect of study midyear, and (after controlling for this and other factors) hierarchical general linear modeling (GLM) was used to examine the following sequence of predictors: domain “g-ness” (a rank-order measure of g saturation) Index of Biological State (IBS; a measure of relaxed/reversed selection operating on g), per capita immigration, and the 2-way interactions IBS × g-ness and Immigration × g-ness. The MLM revealed that the anti-Flynn effect has strengthened in more recent years. Net of this, the GLM found that g-ness was a positive predictor; that is, less aggregately g-loaded measures exhibited bigger IQ declines; IBS was not a significant predictor; however immigration predicted the decline, indicating that high levels of immigration promote the anti-Flynn effect. Among the interactions there was a negative effect of the Immigration × g-ness interaction, indicating that immigration promotes IQ decline the most when the measure is higher in g-ness. The model accounted for 37.1% of the variance among the observations.

Life History Selection and Phenotypic Diversification

Del Giudice (this issue) has written an excellent review of how a reexamination of our understanding of the phenomenology of many conditions commonly considered pathological can be facilitated by a...

A social biogeography of homicide: Multilevel and sequential canonical examinations of intragroup unlawful killings.

A considerable number of publications have examined the effect of various geographical, life history, social, economic and political factors on homicide. However, few studies were interested in examining the effect of these forces in an integrated social biogeography of homicide. This study collected data for 172 nation-states from various publications and databases. Standardized Studentized residuals were extracted from a multilevel model examining the effects of geographical adjacency upon homicide rates. A general linear model was used, with the residuals, to observe the effects of physical, community, social, cultural, and cognitive ecology upon homicide. Two sequential canonical analyses (SEQCA) were conducted to determine the mediating effects among the ecological indicators with respect to homicide. In the SEQCA, we hypothesized physical ecology would lead to communal ecology, in turn leading to social ecology, subsequently leading to cognitive ecology, and ultimately to homicide. A parsimony test concluded that economic growth and inequality fully mediated the relationship between cognitive ecology and homicide residuals. Similarly, the effects of life history upon homicide were fully mediated by social ecology. This study suggests several social ecology factors appear to directly affect homicide; however, other aspects of ecology indirectly affected homicide through influences on social ecology. The effect of indicators of social ecology such as income inequality and the operational sex ratio indicate competition for resources is a significant force generating differences in homicide rates across populations. In conclusion, a suite of evolutionary pressures seems to influence homicide rates, but mainly in a sequential nature rather than simultaneously.

Psicologia evolucionista: uma perspectiva em expansão

Evolutionary Psychology (EP) is a broad theoretic field within Psychology that to understand human nature from the standpoint of evolutionary perspective of neo-Darwinism. Although its emergence dates back to the 1980’s, EP has developed in Brazil only in this century. The aim of the present study was to review systematically the Brazilian scientific publications related to EP and compare them to the international publications in the same period. Therefore, a systematic review of the literature was carried out on the following databases: Virtual Health Library, CAPES Theses Database, and PsycINFO. Studies containing the keyword “Evolutionary Psychology” or its correspondent version in Portuguese were used. The search was carried out considering studies available on the databases until 2010. Brazilian publications were classified by subject matter and method employed, whereas frequencies by year were computed for international studies. Although results showed a growing number of publications related to EP as a general tendency, there were few empirical studies in the area in Brazil. Non-systematic reviews of the literature and studies on general aspects of the evolutionary approach comprised the major part of Brazilian publications. The need of further empirical studies in the area in Brazil, particularly investigations of issues related to personality and psychopathology, is highlighted.

Michael Mann and Societal Aggregation: From Tribe, to Fief, to City-State, to Nation, to Empire

Written over decades, subsuming much of his career as a sociologist, Michael Mann’s four-volume Origins of Social Power pursues one grand theme: Societal aggregation from tribe, to fief, to city-state, to nation, to empire. Mann uses the term, “patterned mess,” in recognition of cultural, historical, and temporal particularities which overlay sociological laws as they have operated through time. Modern theories of gene–culture coevolution work precisely in this way, in that they operate on a fundamental level, even as surface features vary. So when Mann studies internal divisions and external competition as they ebb and flow creating regression and progression along this continuum of aggregation, it is now possible to partially explain this as a function of variation across aggregate life history continua.

Thomas Robert Malthus, Stratification, and Subjugation: Closing the Commons and Opening the Factory

With eminently unpropitious timing, Thomas Robert Malthus wrote of resource competition just as humans were bursting the bonds of organic economies. An Essay on the Principle of Population, in warning of the ills consequent to population density and resultant resource competition, may have, however, underappreciated its evolutionary effects. Although the significance of mortality regime has superseded its overall significance, population density, and the resource competition it brings, was the variable around which life history theory was originally constructed. With the coming of density and accompanying competition, life history theory explains how populations change and stratify as they vie to survive and reproduce. As herein argued, the slowing of life history is a consequence of population density that Malthus could not suspect, but might have appreciated.