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James Flynn on the Flynn Effect

24 Oct

I showed this video to my doctoral students last week. It’s a nice summary of Flynn’s work. I regard the Flynn Effect as one of the most important discoveries, a greatest mysteries, of scientific psychology.

Special brag point: I am the author of the study he mentions on Ohio school examinations.

Brain training increases grey matter volume

15 Aug

On Friday, I reported on a meta-analysis that presented evidence that working memory brain training does not transfer to other cognitive skills. The most recent issue of Personality and Individual Differences carries a paper titled:  “Gray matter volumetric changes with a challenging adaptive cognitive training program based on the dual n-back task.” The n-back task is the most widely used procedure for working memory training in academic research.

Surprisingly, these results do not, necessarily, contradict each other. As noted in the abstract:

“Changes in the gray matter volume of these clusters were correlated with a) behavioral changes across the training program and b) changes in four psychological factors assessed before and after training (fluid and crystallized intelligence, working memory capacity, and attention control). None of these correlations were statistically significant, and therefore, psychological and biological changes were seen as independent.”

Since there working memory training does improve performance on the trained task, we would expect there to be some kind of measurable physical change in the brain. But this does not mean that the training effects are transferable to other cognitive domains.

Uric acid and personality

2 May

Psychology has many interesting findings that have never been adequately explored. One of them is the link between high IQ and gout. Gout is a form of arthritis caused by a high level of uric acid in the body.

Now a study, published in Personality and Individual Differences reports links between serum uric acid and personality:

“Elevated serum uric acid (SUA) is associated with a variety of medical and psychopathological conditions. This study investigated whether elevated SUA is associated with the Five Factor Model of personality. Participants underwent a health examination at two points of time, T1 (N = 3706) and T2 (N = 2104), about 18 months apart. Ordinary least squares (OLS) regressions were used to examine the concurrent and over-18-month associations between the FFM factors and SUA levels. Extraversion was associated with elevated SUA at T1 and T2. Conscientiousness was associated with decreased SUA at T1. The associations of Extraversion and Conscientiousness with SUA decreased to marginal significance when adjusted for body weight as a possible mediator. Agreeableness was associated with decreased SUA at T1 and T2 and persisted after adjustment for covariates. A secondary analysis conducted to examine whether the FFM could predict individuals having above normal SUA levels, showed a trend similar to that observed for the OLS regressions. The associations found have direct relevance to medical and psychopathological conditions associated with elevated SUA.”


Are our brains getting bigger?

17 Feb

A paper in Learning and Individual Differences:

“Secular increases in brain mass over nearly a century have been noted for both males and females in the UK and Germany. It has been argued that such trends may be associated with the Flynn effect. The IQ gain predicted on the basis of these trends is 0.19 and 0.08 points per decade for UK, and 0.2 and 0.15 points per decade for German males and females respectively, indicating a small contribution to the Fullscale IQ trends in these countries (2.95% of the German decadal gain and 12.73% of the UK gain). There is also a sex difference in the rates of brain mass gain in both countries, favoring males. Temporal correlations between the secular trend in UK brain mass and European Flynn effects on Fullscale IQ, Crystallized, Fluid and Spatial abilities reveal correlations ranging from 0.751 in the case of Fluid ability to 0.761 in the case of Crystallized ability. The brain mass increase may be an imperfect proxy for changes in specific neuroanatomical structures important for IQ gains. Its small contribution to these gains is also consistent with the influence of other contributing factors. Increasing brain mass is predicted by the life history model of the Flynn effect as it suggests increased somatic effort allocation into bioenergetically expensive cortical real estate facilitating the development of specialized cognitive abilities.”


Ian Deary describes his research

25 Dec


I highly recommend his book Intelligence: A Very Short Introduction

“The burden of disease and the IQ of nations”

23 Dec

A paper in the journal Learning and Individual Differences:

“The relationship between the conditions of health of the population and the average intelligence quotients (IQs) was examined in a sample of 138 countries. Health conditions were proxied by DALY rates for infectious and parasitic diseases, perinatal and maternal conditions, and nutritional deficiencies. Results show how the burden of considered diseases – and, particularly, of perinatal and maternal – is strongly and negatively related to national IQs even when income, education, and temperature or latitude are controlled for. The effect of education on national IQs is significant, but lesser than that of health. The burden of disease is a strong predictor of international differences in average cognitive abilities. Investment in health in poor countries, and particularly in maternal and neonatal health, would have long-term economic returns by reducing international inequalities.”


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