Samstag, 28. März 2015

Blindness to Equality/Inequality:

There is a certain tendency to think that ones appearance and the appearance of ones siblings are quite different, while, quite often, non-family members experience them as very similar. From a European perspective "all Chinese look alike"; and it has also been said, that, from a Chinese perspective, "all Europeans look alike".
So it seems as if there are two cognitive tendencies/biases: (A) the tendency to perceive more similarity than there actually is (B) the tendency to perceive less similarity than there actually is.
Or in other words: (A) the tendency to perceive the similarities and to ignore the differences (B) the tendency to perceive the differences and to ignore the similarities.
Bluntly said, in some situations people appear to be blind to equality, while in other situations people appear to be blind to inequality.

Donnerstag, 26. März 2015

The genomic-level heritabilities of preparedness and plasticity in human life history: the strategic differentiation and integration of genetic transmissibilities

The genomic-level heritabilities of preparedness and plasticity in human life history: the strategic differentiation and integration of genetic transmissibilities (provisional pdf)
Michael A. Woodley of Menie, Aurelio J. Figueredo, Tomas Cabeza de Baca, Heitor B. Fernandes, Pedro S. Wolf and Candace Black (2015)


Abstract

The Continuous Parameter Estimation Model is applied to develop individual genomic-level heritabilities for the latent hierarchical structure and developmental dynamics of Life History (LH) strategy LH strategies relate to the allocations of bioenergetic resources into different domains of fitness. LH has moderate to high population-level heritability in humans, both at the level of the high-order Super-K Factor and the lower-order factors, the K-Factor, Covitality Factor, and General Factor of Personality (GFP). Several important questions remain unexplored. We developed measures of genome-level heritabilities employing 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. This novel heritability index measures individual genetic transmissibility, therefore opening new avenues for analyzing complex interactions among heritable traits inaccessible to standard structural equations methods. For these samples: (1) moderate to high heritability of factor loadings of Super-K on its lower-order factors is demonstrated, 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, of factor loadings, and of the magnitudes of the correlations among factors are weaker among those with slower LH speeds, demonstrating that inter-individual variation in transmissibility is a function of individual socioecological selection pressures.

Dienstag, 17. März 2015

Is Education Associated With Improvements in General Cognitive Ability, or in Specific Skills?

Is Education Associated With Improvements in General Cognitive Ability, or in Specific Skills?
Stuart J. Ritchie, Timothy C. Bates, and Ian J. Deary (2015)


Abstract

Previous research has indicated that education influences cognitive development, but it is unclear what, precisely, is being improved. Here, we tested whether education is associated with cognitive test score improvements via domain-general effects on general cognitive ability (g), or via domain-specific effects on particular cognitive skills. We conducted structural equation modeling on data from a large (n 1,091), longitudinal sample, with a measure of intelligence at age 11 years and 10 tests covering a diverse range of cognitive abilities taken at age 70. Results indicated that the association of education with improved cognitive test scores is not mediated by g, but consists of direct effects on specific cognitive skills. These results suggest a decoupling of educational gains from increases in general intellectual capacity.

Montag, 16. März 2015

By their words ye shall know them: Evidence of negative selection for general intelligence in vocabulary usage since the mid 19th century

By their words ye shall know them: Evidence of negative selection for general intelligence in vocabulary usage since the mid 19th century (provisional pdf)
Michael A. Woodley of Menie, Heitor B. Fernandes, Aurelio José Figueredo and Gerhard Meisenberg (Mar 2015)


Abstract

It has been theorized that declines in g due to negative 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 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 1850 to 2005. Consistent with predictions, words with higher difficulties (δ parameters from Item Response Theory) and stronger negative correlations between pass-rates and completed fertility presented a steeper decline in use over time, than less difficult and less negatively selected words, which increased in use over time, suggestive of a Flynn effect. These findings persisted when explicitly controlled for word age, literacy rates and temporal autocorrelation. These trends constitute compelling evidence that both producers and consumers of text have experienced declines in g since the mid-19th Century.

You Can Give a Boy a Doll, but You Can't Make Him Play With It


You Can Give a Boy a Doll, but You Can't Make Him Play With It
Christina Hoff Summers (2012)


"One of the largest and most persistent differences between the sexes are children's play preferences." *


[via Oliver Scott Curry]

*the quote is from David Geary