Matthew A. Sarraf’s research while affiliated with Beverly Hospital, Boston MA and other places

The effect of ancestral genetic diversity, captured by a novel index, on the levels of three latent variables (Self-efficacy, General Phobia, and General Growth factors) is examined using a large pediatric imaging sample to test for the presence of outbreeding depression (i.e., worse outcomes among individuals in proportion to their degree of ancestral diversity). No evidence is found for this effect on any of the three latent variables, controlled for age, household income, parental education, and sex, and the main effects of a set of five molecular-genetic ancestry measures. Claims that “wide racial crosses” would cause “disharmonious combinations” of traits in offspring, leading to physical and psychological abnormalities, enjoyed wide support among eugenicists prior to the Second World War. Such theories were rooted in Mendelian inheritance models. Our results are consistent with the finding that the genetic architecture of most complex human traits is additive. Notions of severe outbreeding depression effects on physical and mental health historically were used to support racist policies, and our results can be said to challenge the foundations of these ideas.

It has been argued that reduced inbreeding depression and associated increased heterosis (hybrid vigor), due to greater gene flow between human subpopulations, is the cause of the Flynn effect (rising IQ-test performance over time). Using genotypic data from the Wisconsin Longitudinal Study, three estimates of genome-wide runs of homozygosity (ROH) are generated for a subsample of unrelated individuals of European descent. These estimates are used in a between-generation regression model to predict offspring advantage over parents in educational attainment (EA; years of schooling). After controlling for a variety of covariates, it is found that a variable combining both the numbers and lengths of ROH is a statistically significant positive predictor of the offspring EA advantage. Maternal, rather than paternal, differences are found to drive the effect when these parental influences are examined separately. Since the heterosis hypothesis (HH) explicitly predicts that this analysis would yield the opposite finding, the result constitutes substantial evidence against the HH. By contrast, the life history model of the Flynn effect (LHM) satisfactorily explains the current findings, positing that slowing life history speed increases maternal investment (MI) into offspring exhibiting greater coefficients of genetic relatedness as a means of raising inclusive fitness. According to the LHM, the Flynn effect stems, at least in part, from MI enhancing opportunities for the cultivation of narrow cognitive abilities (e.g., through greater exposure to highly predictable environments, such as in good schools). The significant independent effect of assortative mating observed here is also consistent with the LHM, as are other patterns found in these data.

Domino Theory posits that Communism spreads via emulation or force between nations as a function of geographic adjacency, the theory being so named because this dynamic is often likened to the toppling of dominoes. Using the 1917 Russian Revolution (RR) as a starting point, it is found that geographic distance between Moscow and the capital cities of countries that at one point were or are (either in part or in whole) Communist states strongly predicts the lag (in years) between the RR and the year in which these countries first experienced Communism in some form (r = 0.778, 95% CI = 0.628 to 0.872, n = 45 countries). In a subsample of 36 countries, the pair-wise genetic distance between the population of Russia and the populations of the other countries strongly mediates this relationship. A cladogram based on genetic distance between these national populations indicates strong lambda and kappa signals, meaning that Communism-uptake lag is inversely proportional to the degree of shared ancestry between populations, and that it spreads rapidly among populations once introduced into new regions. Controlling for lambda in regression revealed significant positive influences of historical disease prevalence and GDP per capita on the lag variable. These results suggest that the process that Domino Theory specifies may principally be a function of cultural transmission biased by genetic distance (relative to the population of Russia). Controlling for genetic distance, countries with higher relative wealth and historical disease prevalence experienced Communism later, possibly due to the buffering effects of historical reductions in poverty and of forms of evoked culture that are incompatible with (basic) communist ideology (e.g. strong xenophobia and religiosity, and other cultural expressions of the behavioral immune system). These two terms also interact positively, meaning that among countries exhibiting high historical disease burdens, increased relative wealth inhibited the development of Communism to the greatest degree.

Introduction The degree to which (self-reported) social class predicts parent-offspring resemblance for educational attainment (EA) is examined in a globally representative dataset of 69,116 individuals sourced from 56 countries. Methods A hierarchical general linear model is used to predict participant EA with the two-way interaction between class and parental EA, after controlling for regional effects, the main effects of age, class, parental EA, and interactions among these. Results Social class-by-parental EA interaction negatively predicts participant EA (semipartial r = −0.04, 95% CI = −0.05 to −0.03), meaning that among those who report belonging to a “higher” social class, the degree of parent-offspring resemblance for EA is reduced, contrary to the Scarr-Rowe hypothesis, which holds that genetic influences on cognitive ability and related phenotypes (captured here in part by parent-offspring resemblance) should be greater among those from higher socioeconomic status (SES) backgrounds. These results replicate using a quantile regression model, where it was found that among those with lower social class ordinals, the strength of the parent-participant EA association is significantly stronger relative to those in the highest ordinal. No significant sex differences are present. Discussion These findings are consistent with the compensatory advantage hypothesis, which predicts decreased heritability of EA and related phenotypes among affluent families, as increased access to educational resources should enhance opportunities for cognitive growth in a way that compensates for intrinsic disadvantages.

There is a long history of academic and non-academic activism directed against those areas of social-scientific research, specifically behavior genetics and differential psychology (especially intelligence research) , that seek to understand the determinants of variation in socially significant psychological and behavioral traits and outcomes. This research becomes particularly controversial when it addresses the potential genetic contributions to differences between population groups, e.g. studies of socially important variables such as intelligence and any variation in them between "racial" or "ethnic" groups. . We consider recent controversies related to these areas of inquiry. Crucial among these is an attempt to brand science on population differences as part of a particular form of rightist political activism, aiming to insert justifications for “White nationalism” and related ideologies into scientific, political, and public discourse. Unfortunately, the coherence of this thesis depends heavily on guilt-by-association allegations and suppression of conflicting evidence. We begin with a more general review of controversies in the disciplines at issue and then review, and further challenge, the specific argument concerning such political activism. We subsequently argue that these criticisms might themselves be embedded within a program of egalitarian activism/left-wing activism, which includes certain scholars and scientists working in relevant fields (e.g., sociogenomics), who aim to ensure that science is both conducted and presented to the public in ways that could only further egalitarian moral-political goals. Ultimately, this egalitarian activism is harmful, as it has broader chilling effects on research and science communication (claims for which we offer empirical evidence), and ethics, as it risks fomenting political polarization. To be sure, those on the political right are not innocent either. Many have engaged in behavior that has fanned the flames of controversy in these areas of science and have spread erroneous ideas about findings in them. It would be ideal if efforts were made to depoliticize social science in particular to the greatest extent possible, but a more productive course of action might involve critical introspection and the active pursuit of lines of research that challenge potential misconceptions.