Saturday, 19 September 2015

g for Latinos

When genomic analysis becomes cheap and reliable we will be able to give our position in population space with exquisite accuracy, but for the time being we will have to use the occasional classification of genetic and cultural groups can by their language. Yes, languages often parallel genetics (why not) but Hispanic is a broad church, though 63% are Mexican.


Miranda C Richmond and Thomas R Coyle

University of Texas at San Antonio,

This study examines relations among g, non-g factors (unrelated or weakly related to g), and academic performance. The non-g factors are grit and conscientiousness. Conscientiousness has been shown to predict academic performance beyond g, and grit has been shown to predict outcomes beyond conscientiousness. Ethnic differences in g and non-g factors have been examined primarily for Blacks and Whites.

The current study examines ethnic differences in g and non-g factors for Hispanic and Whites. In addition, the study compares the relative influence of conscientiousness and grit (beyond g) in predicting college GPA. Subjects (215 female, 80 male, mean age = 18.6 (±1.1) years) were drawn from the subject pool at the University of Texas at San Antonio. g was estimated using SAT subtest scores (math, verbal, writing), Wonderlic scores, and Raven’s Advanced Progressive Matrices scores. Conscientiousness was measured with the Big Five Inventory, and grit was measured with the Grit short form (Grit-S). College GPAs were based on academic records.

Ethnic differences in the predictive validity of g and non-g factors for GPA were assessed using multigroup (182 Hispanic, 83 White) structural equation modelling (SEM). Grit and conscientiousness were weakly related to g (r = -.13, -.06 respectively), confirming their non-g status. Multigroup analyses indicated that the direct effect of g on GPA (controlling non-g factors) was stronger for Whites than Hispanics (Whites: β = .446 (.079), p < .001; Hispanics: β = .398 (.045), p <.001).

Although the relation between g and conscientiousness was not significant for either group, the relation between g and grit was negative for Hispanics (β = -.086 (.026), p < .01) and positive for Whites (β = .144 (.038), p < .001). In addition, conscientiousness reliably predicted GPA (controlling grit) for both groups (Whites: β = .255 (.094), p < .01; Hispanics: β = .294 (.053), p < .001). Indirect effects were non-significant for both groups.

This study examined relations among g, non-g factors (grit and conscientiousness), and GPA for Hispanics and Whites. g predicted GPA (controlling non-g factors) better for Whites than Hispanics, suggesting that g is differentially predictive for Hispanics and Whites. This pattern is consistent with prior research showing that g predicts academic achievement better for higher ability groups (Coyle, Snyder et al., 2011). In addition, conscientiousness predicted GPA for both groups (controlling grit), but grit did not predict GPA for either group (controlling conscientiousness), suggesting that conscientiousness is a better predictor of academic achievement. These results have implications for the identification of non-g traits that might enhance student success.


  1. Hispanics as a whole may be 63% Mexican, but Hispanics in Texas are likely more so.

    Despite history, most Hispanics in Texas are immigrants or descended from people who immigrated in the past 50-60 years; I would expect that they are higher on measures of "grit" than their source population, while Anglos in Texas are probably less filtered for grit, which might explain variations in the effect of grit.

    For that matter, the abstract doesn't say how the groups compared in IQ, conscientiousness, or grit.

    1. Get further details from the authors. If I get the fuller paper I will post about it again.