IQ on the rise: the Flynn effect in rural Kenyan children

Abstract - Multiple studies have documented significant IQ gains over time, a phenomenon labeled the Flynn effect. Data from 20 industrialized nations show massive IQ gains over time, most notably in culturally reduced tests like the Raven's Progressive Matrices. To our knowledge, however, this is the first study to document the Flynn effect in a rural area of a developing country. Data for this project were collected during two large studies in Embu, Kenya, in 1984 and 1998. Results strongly support a Flynn effect over this 14-year period, with the most significant gains found in Raven's matrices. Previously hypothesized explanations (e.g., improved nutrition; increased environmental complexity; and family, parental, school, and methodological factors) for the Flynn effect are evaluated for their relevance in this community, and other potential factors are reviewed. The hypotheses that resonate best with our findings are those related to parents' literacy, family structure, and children's nutrition and health.     

Resolving the IQ paradox: heterosis as a cause of the Flynn effect and other trends

IQ test scores have risen steadily across the industrialized world ever since such tests were first widely administered, a phenomenon known as the Flynn effect. Although the effect was documented more than 2 decades ago, there is currently no generally agreed-on explanation for it. The author argues that the phenomenon heterosis represents the most likely cause. Heterosis, often referred to as hybrid vigor, is a genetic effect that results from matings between members of genetically distinct subpopulations, such as has been occurring in human populations through the breakup of small, relatively isolated communities owing to urbanization and greater population mobility. In Part 1 of the article, empirical findings are listed that are consistent with a heterosis hypothesis but render other hypotheses either implausible or very difficult to test. In Part 2, a formal model of the process of heterosis is presented. The goal of the modeling is to develop a quantitatively rigorous method for estimating the potential contribution of heterosis in the Flynn effect, as well as trends observed in other heritable traits and conditions.     

Item-response theory modeling of IQ gains (the Flynn effect) on crystallized intelligence: Rodgers' hypothesis yes,Brand's hypothesis perhaps

Potential explanations for generational intelligence test score gains continue to be subject to intense debate and scrutiny in the scientific community. However, the explanatory value of some of the proposed causes remains difficult to determine, since only little empirical evidence is available. To clarify the role of two scarcely investigated theories accounting for the Flynn effect, this study set out to examine the role of changing test-taking behavior (Brand's hypothesis) and of a narrowing of the IQ ability distribution (Rodgers' hypothesis). Archival records of crystallized intelligence test performance over a time-span of 17 years of a large number of psychiatric inpatients and outpatients in Austria were investigated (N = 5445; 1978–94). This sample was particularly suitable to investigate our hypotheses since participants were under no pressure to perform which makes observed changes in test taking behavior attributable to personal style and ability rather than differential performance in pressure situations. Analytical approaches of both classical test theory and item response theory (IRT) yielded gains of 1.0 to 2.4 IQ points per decade. Test-taking behavior indicative of guessing and decreasing population IQ variability appeared to contribute both to IQ test score gains. IRT-based analyses showed that gains were largely preserved when controlling for highest educational qualification, while the test instrument showed measurement invariance between cohorts. However, IRT-based results also suggested that changes in test-taking behavior might not necessarily reflect increased guessing, but item drift instead. In all, this evidence emphasizes better performance of individuals of the lower tail of the IQ ability distribution in more recent years as one important contributing factor for generational IQ test score gains.     

The effect of a commercial game on children's block design scores on the WISC-R IQ test

Two experiments investigated the extent to which 10-year old children's scores on the WISC-R Block Design subtest were affected by prior experience with a specific commercial game that involved blocks and matching patterns. Experiment 1 found that 12 10-year old children who happened to have experience with the particular commercial game scored approximately three scaled score points higher on the WISC-R Block Design subtest than 24 matched children without game experience. In Experiment 2, 24 children who did not have prior experience with this particular commercial game were randomly assigned either to a Game condition (involving two 15-minute sessions with the game) or to a No-Game condition (which involved no further game experience). Children in the Game condition subsequently increased their WISC-R Block Design scores more than children in the No-Game condition. Taken together, the experiments indicate that relatively brief interactions with a commercial game can cause a significant improvement in children's performance on an IQ subtest.     

School-level genetic variation predicts school-level verbal IQ scores: Results from a sample of American middle and high schools

Research has consistently revealed that average IQ scores vary significantly across macro-level units, such as states and nations. The reason for this variation in IQ, however, has remained at the center of much controversy. One of the more provocative explanations is that IQ across macro-level units is the result of genetic differences, but empirical studies have yet to examine this possibility directly. The current study partially addresses this gap in the literature by examining whether average IQ scores across thirty-six schools are associated with differences in the allelic distributions of dopaminergic polymorphisms across schools. Analysis of data drawn from subjects (ages 12-19 years) participating in the National Longitudinal Study of Adolescent Health provides support in favor of this perspective, where variation in school-level IQ scores was predicted by school-level genetic variation. This association remained statistically significant even after controlling for the effects of race.     

"Panic": the impact of Le Bon's crowd psychology on U.S. military thought

The controversial crowd psychology of Gustave Le Bon has been both praised as an incisive contribution to social theory and also condemned as a doctrine of irrationality and mass manipulation associated with fascism. New archival documentation now demonstrates that Le Bon exercised significant influence on U.S. military thinking and practice through World War II. Army writings and officer training on morale, leadership, and battlefield psychology rested substantially on his theory of crowds, particularly regarding races and panic. Le Bon's racial psychology took on additional importance when the African-American 92 nd Infantry Division panicked during combat in Italy. This new evidence offers an excellent case study of the direct and enduring impact of a peculiar type of social psychology on the institutional culture of the army from the classrooms at the Army War College to the battlefield itself.     

Expanding variance and the case of historical changes in IQ means: a critique of Dickens and Flynn (2001)

The Flynn effect is the rise in mean IQ scores during the 20th century, amounting to about 0.33 IQ points per year. Many theoretical explanations have been proposed, though none are universally accepted. W. Dickens and J. R. Flynn's (2001) new approach explains the large IQ changes by means of recursive models of IQ growth. A salient feature of their models is that IQ phenotypes and their supportive environments are correlated; in addition, environmental effects can rebound on phenotypic IQ to increase or lower IQ. In this critique, the authors examine an empirical challenge to their models, which typically imply large changes in IQ variance. However, the historical rise in IQ mean level has not been accompanied by substantial variance changes, a finding inconsistent with the properties of the proposed model.     

The epidemiology of mental retardation: challenges and opportunities in the new millennium

There are a number of problems and challenges in relating the science of epidemiology to mental retardation (MR). These relate to how MR is defined and classified and how these definitions may change over time. These as well as other differences in ascertainment sources and methods need to be considered when comparing MR prevalence over time and place. On the other hand, advances in technology also provide new and efficient methods of data collection both by data linkage and by use of web-based methods to study rare diseases. While prevalence studies have not been individually reviewed, we have examined the range of data including recent studies relating to how prevalence differs according to age, gender, social class and ethnicity. Some problems with available etiological classification systems have been identified. Recent etiological studies, most of which use different classification systems, have been reviewed and explanations have been postulated to account for differences in results. Individual risk factors for MR are considered whilst the option of considering a population as opposed to a high risk strategy to MR prevention is raised. This might well involve improving the social milieu surrounding the occurrence of individual risk factors. The impact of biotechnological advances such as antenatal and neonatal screening and assisted reproduction on MR are discussed. The issue of how inequalities in access to technology may impact on case identification and even have the potential to further widen inequalities is raised. The importance of extending the use of epidemiological tools to study the social, health and economic burden of MR is also emphasized. However, in order to apply to MR the "prevention-intervention-research" cycle, which surely underpins all epidemiology, it is vital to ensure that the methodological challenges we raise are adequately addressed.     

Presidential IQ, Openness, Intellectual Brilliance, and Leadership: Estimates and Correlations for 42 U.S. Chief Executives

Individual differences in intelligence are consistently associated with leader performance, including the assessed performance of presidents of the United States. Given this empirical significance, IQ scores were estimated for all 42 chief executives from George Washington to G. W. Bush. The scores were obtained by applying missing-values estimation methods (expectation-maximization) to published assessments of (a) IQ (Cox, 1926; n =  8), (b) Intellectual Brilliance (Simonton, 1986c; n =  39), and (c) Openness to Experience (Rubenzer & Faschingbauer, 2004; n =  32). The resulting scores were then shown to correlate with evaluations of presidential leadership performance. The implications for George W. Bush and his presidency were then discussed.     

The impact of environmental noise on mealtime social interactions in a residential facility for persons with mental retardation

Four levels of environmental noise were experimentally manipulated during lunch and dinner in a residential living unit for 10 behaviorally disordered persons with mental retardation. During the highest noise conditions, there appeared to be some suppression of social interaction between these people, while interaction rates were uniformly higher during softer noise conditions. This effect was evident at both lunch and dinner. Staff members were less affected by the fluctuation in noise levels, although lunchtime staff engaged in more interactions with clients when both the radio and TV were played softly.     

The Bermond-Vorst Alexithymia Questionnaire: a measurement invariance examination among U.S. Anglos and U.S. Hispanics

The aim of this article is to assess the measurement invariance of the Bermond-Vorst Alexithymia Questionnaire (BVAQ) in U.S. Anglo (n = 490) and U.S. Hispanic ( n = 379) samples of college students. The BVAQ items demonstrated invariance of the factor loadings, the latent item intercepts, and unique factor variances. However, Hispanics had higher verbalizing scores and lower fantasizing scores on the latent variables. As a whole, the BVAQ requires additional testing and/or refinement for use with a Hispanic sample. Until such refinements, the authors recommend that the Toronto Alexithymia Scale-20 be used with U.S. Hispanic samples.     

MMPI-2 scores of Puerto Rican, Mexican, and U.S. Latino college students: a research note

In this brief report, we present MMPI-2 basic validity and clinical scale data of Latino-descent persons from Puerto Rico (n = 290), Mexico (n = 1,920), and the United States (n = 28). All were administered one of three Spanish translations of the MMPI-2. A review of the mean scores of these respective groups indicates similarities across all scales. Differences among these three groups, with the exception of the Mf scale (which is keyed to sex), were well within the one standard deviation band. More importantly, these findings are promising given the fact that three different translations of the MMPI-2 were applied.     

The prevalence of mental retardation: Cross-cultural considerations from Sweden and the United States

Recent reports from Sweden and other European countries have shown a sharp disparity between their incidence and prevalence figures on mild mental retardation and similar figures in the U.S. (Grunewald, 1979; Martin, Blodgett, Edwards, Geer, & Melcher, 1974; Robinson & Robinson, 1976).The purpose of this paper is to provide a model of intellectual performance that might explain such disparities and predict future levels of occurrence of mild mental retardation. Such explanations should have relevance for our views on the development of intellectual ability as well as, on a practical level, planning the allocation of treatment resources. Such planning clearly depends upon the number of children having the condition in question.Over the past few decades we have progressed substantially in our ability to describe mental retardation and to differentiate it from conditions that superficially resemble it; such as, autism, learning disabilities, schizophrenia, etc., (Baroff, 1974; Robinson & Robinson, 1976). Our ability to identify variables that relate to mild mental retardation also has developed substantially, but correlation does not necessarily lead to understanding. One of the large set of variables that often is associated with mild mental retardation in the U.S. is poverty. But “poverty” is too broad a variable to be explanatory. Such a dimension is a surrogate factor standing in the place of other variables, not yet understood, that control, in part, the actual process, by which the child develops the condition of mild mental retardation (Kirk & Gallagher, 1983). A series of papers has been presented by psychologists in Sweden that allow us to address this issue.The ability to observe two cultures, Sweden and the U.S., that have both substantial similarities and differences provides a natural comparison of the prevalence of mental retardation that would be impossible to achieve through experimental manipulation. Prevalence is used here as the total number of cases present in a population group during a specific interval of time (Kramer, 1975).     

An estimate of the Flynn Effect: changes in IQ and subtest gains of 10-yr-old French children between 1965 and 1988

The significant increase in IQ in the industrialised countries during recent decades, known as the eponymous Flynn Effect, tends to be given numerous explanations (progress in schooling, television, nutrition, etc.). One way of studying this effect consists of assessing in which subtests the change in IQ takes place. Using the comparison among 120,000 French children on an intelligence test in 1965 and the results of 8640 children on the same test in 1988, Greenfield's hypothesis is discussed: that television and other media using graphical representations have induced an improvement in spatial and visual capacities to the detriment of capacities relating to vocabulary. The results are compatible with Greenfield's hypothesis, although other explanations are still possible.     

The Psychodynamic Assumptions of the U.S. Constitution

The U.S. Constitution is a blueprint for the design of a government which reflects the consistent application of an understanding of the emotions and interests driving the political activity of individuals and groups. This understanding is articulated in the writings of key proponents of the Constitution, and clarified by its historical and philosophical context. Their theories are congruent with psychoanalytic perspectives on narcissism, leadership, group dynamics, and the role of transitional space in cultural life. The concept of interests, reformulated in psychoanalytic terms, is a useful addition to our understanding of political behavior.     

Ethnic Pride and Cardiovascular Health Among Mexican American Adults Along the U.S.-Mexico Border

This study addressed the association between items from the General Acculturation Index (GAI) and cardiovascular health. Specifically, we assessed whether ethnic pride was associated with health outcomes after controlling for items regarding language, place where the childhood was spent and ethnic interaction. The study was a cross sectional analysis of demographic and clinical data from a border population of Mexican American adults (n=316) at risk for cardiovascular disease (CVD). Outcomes included smoking and diabetes status, Framingham risk, and metabolic syndrome. Ethnic pride was associated with lower diabetes prevalence, lower Framingham risk, and fewer risk factors for metabolic syndrome, but was not associated with smoking status. Ethnic pride was not associated with the other acculturation items of the GAI. Among an at-risk border population, ethnic pride functioned independently of other acculturation indicators. Ethnic pride may act as a protective factor for diabetes, metabolic syndrome and CVD risk status.     

Informed Consent Revisited: Japan and the U.S.

Informed consent, decision-making styles and the role of patient–physician relationships are imperative aspects of clinical medicine worldwide. We present the case of a 74-year-old woman afflicted with advanced liver cancer whose attending physician, per request of the family, did not inform her of her true diagnosis. In our analysis, we explore the differences in informed-consent styles between patients who hold an “independent” and “interdependent” construal of the self and then highlight the possible implications maintained by this position in the context of international clinical ethics. Finally, we discuss the need to reassess informed-consent styles suitable to the needs of each patient regardless of whether he or she resides in the United States or in Japan.     

Rorschach blends, IQ, and the effect of R.

A correlation of .351 was found between the Rorschach blend score and the Wechsler Adult Intelligence Scale Full Scale IQ (WAIS FSIQ) score for 70 outpatients. When the total number of responses (R) was partialed out, however, the correlation dropped to .255. We concluded that it is advisable to take into account the effects of R in validity studies showing significant but low correlations. The importance of further exploring the psychological implications of R was stressed.