L’hypothèse toutes choses étant égales, The all other things being equal assumption

(English text in bold.)

Il semblerait que bon nombre de gens, en particulier sur Internet, confondent absolument tout quand il s’agit de parler d’un sujet concernant des études de corrélations dans les sciences sociales. Ils proposent un point de vue tronqué, biaisé, incomplet de la réalité telle qu’elle est actuellement.

I get the impression that a lot of people around the web confound absolutely everything when talking about correlations on the topic of social sciences. They supply a biased, incomplete, or truncated reality of what actually really is.

Continue reading

Introduction to Structural Equation Modeling: Issues and Practical Considerations

Introduction to Structural Equation Modeling: Issues and Practical Considerations

Pui-Wa Lei and Qiong Wu, The Pennsylvania State University (Fall 2007)

Structural equation modeling (SEM) is a versatile statistical modeling tool. Its estimation techniques, modeling capacities, and breadth of applications are expanding rapidly. This module introduces some common terminologies. General steps of SEM are discussed along with important considerations in each step. Simple examples are provided to illustrate some of the ideas for beginners. In addition, several popular specialized SEM software programs are briefly discussed with regard to their features and availability. The intent of this module is to focus on foundational issues to inform readers of the potentials as well as the limitations of SEM. Interested readers are encouraged to consult additional references for advanced model types and more application examples.

Continue reading

On the partial mediating role of processing speed between black-white differences, IQ and GPA

In the present article, I demonstrate that processing speed (using ASVAB speeded subtests) has a modest predictive validity over the g factor extracted from the ASVAB (non-speeded subtests) in predicting overall GPA in the NLSY97, within black, hispanic and the white sample. Next, I investigate the mediation of speed in the black-white difference in IQ (g). For both analyses, processing speed accounts for a modest portion of these associations. Nonetheless, some issues related with such ‘psychometric speed’ measures need to be clarified.

Continue reading

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

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

Kevin M. Beaver, John Paul Wright (2011)


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.

Continue reading

Avoir des enfants rend-il heureux ?

Kanazawa (2004) avait démontré qu’avoir des enfants ne rendait pas les parents plus heureux. La parentalité diminue en fait le bonheur. En utilisant les données du General Social Survey, il montre que la parentalité a un effet négatif sur le bonheur (variable dépendante) mais que le fait d’être marié était associé à un bonheur plus élevé. Je vais ici tenter de répliquer ce résultat. Ensuite, je commenterais l’étude de Myrskylä & Margolis (2012) dont la conclusion des auteurs diffère de la mienne. Enfin, j’expliquerai que ces mesures du “bonheur général” ne sont pas des évaluations adéquates du bonheur.

Continue reading