Metacarpophalangeal pattern profile analysis of a sample drawn from a North Wales population

This is tha author's PDF version of an article published in Annals of human biology© 2001. The definitive version is available at http://www.tandf.co.uk/journalsSexual dimorphism and population differences were investigated using metacarpophalangeal pattern profile (MCPP) analysis. Although it is an anthropmetric technique, MCPP analysis is more frequently used in genetic syndrome analysis and has been under-used in the study of human groups. The present analysis used a series of hand radiographics from Gwynedd, North Wales, to make comparisons, first, between the sexes within the sample and then with previously reported data from Japan. The Welsh sexes showed MCPP analyses that indicated size and shape differences but certain similarities in shape were also evident. Differences with the Japanese data were more marked. MCPP anlysis is a potentially useful anthropmetric technique but requires further statistical development

Dusting off the diffuse interstellar bands: DIBs and dust in extragalactic SDSS spectra

Using over a million and a half extragalactic spectra we study the properties of the mysterious Diffuse Interstellar Bands (DIBs) in the Milky Way. These data provide us with an unprecedented sampling of the skies at high Galactic-latitude and low dust-column-density. We present our method, study the correlation of the equivalent width of 8 DIBs with dust extinction and with a few atomic species, and the distribution of four DIBs - 5780.6A, 5797.1A, 6204.3A, and 6613.6A - over nearly 15000 squared degrees. As previously found, DIBs strengths correlate with extinction and therefore inevitably with each other. However, we show that DIBs can exist even in dust free areas. Furthermore, we find that the DIBs correlation with dust varies significantly over the sky. DIB under- or over-densities, relative to the expectation from dust, are often spread over hundreds of square degrees. These patches are different for the four DIBs, showing that they are unlikely to originate from the same carrier, as previously suggested.Comment: MNRAS accepte

Black-White Differences on IQ and Grades: The Mediating Role of Elementary Cognitive Tasks

The relationship between IQ scores and elementary cognitive task (ECT) performance is well established, with variance on each largely reflecting the general factor of intelligence, or g. Also ubiquitous are Black-White mean differences on IQ and measures of academic success, like grade point average (GPA). Given C. Spearman\u27s (Spearman, C. (1927). The Abilities of Man. New York: Macmillan) hypothesis that group differences vary directly with a test\u27s g loading, we explored whether ECT performance could mediate Black-White IQ and GPA differences. Undergraduates (139 White and 40 Black) completed the Wonderlic Personnel Test, followed by inspection time and choice reaction time ECTs. Despite restriction of range, ECT performance completely mediated Black-White differences on IQ (d=0.45). Group differences on GPA (d=0.73), however, were larger and ECT performance did not mediate them. We discuss findings in light of Spearman\u27s hypothesis

Only In America: Cold Winters Theory, Race, IQ, And Well-Being

ColdWinters Theory (CWT; Lynn, 1991) offers a viable explanation for race differences in intelligence. It proposes that IQ gaps exist because of different evolutionary pressures faced by the ancestral humanswho left Africa, comparedwith thosewho remained. Support for CWT comes by showing correlations between national temperature and IQ. Here we test whether temperature correlates with IQ (and other well-being variables) across the 50 U.S. states. Although human evolution is recent, copious and regional (Wade, 2014), insufficient time has passed for it to have operated on non-native residents of the USA. Instead, CWTmust predict no difference—or remain agnostic—on the existence of state-level correlations between temperature and IQ. Nonetheless, even after controlling for race, temperature strongly predicts state: IQ, religiosity, crime, education, health, income and global well-being. Evolution is therefore not necessary for temperature and IQ/well-being to co-vary meaningfully across geographic space

The Inspection Time and Over-Claiming Tasks as Predictors of MBA Student Performance

Elementary cognitive tasks (ECTs) are typically used in laboratory settings for basic research on the structure of intelligence. More recently, ECTs have been shown to predict important educational and clinical outcomes. Here we found that ECTs possess both criterion and incremental validity over IQ and the graduate management admission test (GMAT) as predictors of (N = 116) MBA student grades and scores on a capstone exam. Validity coefficients for the ECTs ranged from 0.24 to 0.50. A median split on an ECT component showed that the best-performing ECT group had substantially higher grades, exam scores, IQs and GMAT scores. The inspection time ECT possessed significant incremental validity over both IQ and the GMAT. ECTs could therefore be promising additions to the arsenal of assessment techniques currently used in predicting important real-world outcomes

Using machine learning to classify the diffuse interstellar bands

Using over a million and a half extragalactic spectra we study the correlations of the Diffuse Interstellar Bands (DIBs) in the Milky Way. We measure the correlation between DIB strength and dust extinction for 142 DIBs using 24 stacked spectra in the reddening range E(B-V) < 0.2, many more lines than ever studied before. Most of the DIBs do not correlate with dust extinction. However, we find 10 weak and barely studied DIBs with correlations that are higher than 0.7 with dust extinction and confirm the high correlation of additional 5 strong DIBs. Furthermore, we find a pair of DIBs, 5925.9A and 5927.5A which exhibits significant negative correlation with dust extinction, indicating that their carrier may be depleted on dust. We use Machine Learning algorithms to divide the DIBs to spectroscopic families based on 250 stacked spectra. By removing the dust dependency we study how DIBs follow their local environment. We thus obtain 6 groups of weak DIBs, 4 of which are tightly associated with C2 or CN absorption lines.Comment: minor changes, MNRAS accepte

Putting Spearman\u27s Hypothesis to Work: Job IQ as a Predictor of Employee Racial Composition

Job complexity and employee intelligence covary strongly. Likewise, race differences exist on mean IQ / g scores. Spearman’s hypothesis predicts that race differences on cognitive tests are mainly g differences, and that the former should covary with how well mental tests measure the latter. Here we use jobs as “mental tests,” and predict that as job IQ increases, the percent of White and Asian workers will increase, while the percent of Black workers will decrease. We found moderate to strong support for Spearman’s hypothesis across these three racial groups. We also found a very large correlation (.86) between job IQ and complexity, as measured by the U.S. Federal Government’s Dictionary of Occupational Titles classification scheme. In sum, like different mental tests, different jobs are more or less g-loaded. And, consistent with Spearman’s hypothesis, the g-loading of a job predicts its demographic composition

An Empirical Relation between Sodium Absorption and Dust Extinction

Dust extinction and reddening are ubiquitous in astronomical observations and are often a major source of systematic uncertainty. We present here a study of the correlation between extinction in the Milky Way and the equivalent width of the NaI D absorption doublet. Our sample includes more than 100 high resolution spectra from the KECK telescopes and nearly a million low resolution spectra from the Sloan Digital Sky Survey (SDSS). We measure the correlation to unprecedented precision, constrain its shape, and derive an empirical relation between these quantities with a dispersion of order 0.15 magnitude in E(B-V). From the shape of the curve of growth we further show that a typical sight line through the Galaxy, as seen within the SDSS footprint, crosses about three dust clouds. We provide a brief guide on how to best estimate extinction to extragalactic sources such as supernovae, using the NaI D absorption feature, under a variety of circumstances.Comment: MNRAS accepte