Psychometrics and biology

Jensen AR 1998 The factor the science of mental ability. Praeger, Westport, CT Jensen AR 2000 The factor psychometrics and biology. In The nature of intelligence. Wiley, Chichester (Novartis Found Symp 233) p 37—46 Jensen AR 2000 Charles Spearman the discoverer of g. In Kimble GA, Westheimer M (eds) Portraits of pioneers in psychology. Vol IV. American Psychological Association, Washington DC, and Erlbaum, NJ, in press... 

Galton F 1869 Hereditary genius an inquiry into its laws and consequences. Macmillan, London Jensen AR 1993 Spearman s links between psychometrics and biology. Ann NY Acad Sci 702 103-129... 

Similar data evaluation problems exist in other scientific fields and can also be treated by multivariate statistical data analysis, for instance, in economics (econometrics), sociology, psychology (psychometrics), medicine, biology (chemotaxonomy),... 

Psychometric procedures like Spearman—Brown provide psychological windows on human variation akin to the microscope in biology and the telescope in astronomy. With an average inter-item correlation of 0.20, a mere 40 item scale can generate a composite whose common (reliable) variance is 91%. This is how psychometrics distils dimensions of common variance for submission to construct validation procedures. 

Size of the brain is among the better established biological correlates of mental test scores, with a moderate effect size. There is some evidence for a small correlation between nerve conduction velocity and psychometric intelligence, and some preliminary work relating aspects of brain metabolism to mental abilities. These areas are reviewed by Deary Caryl (1997). 

The direct quantitative analysis of expired air, body fluids, or tissue for the presence of the hazardous agent or its metabolites and/or evidence of biologic impairment quantified by the use of physiologic, psychometric, or biochemical tests. 

The present study was designed to evaluate the relationship between different biological indicators of body lead burden and some neuropsychological functions in 7-8-year-old children, living in an industrial area polluted by lead. The neuropsychological functions were estimated by a battery of 6 psychometric tests. Lead was measured in blood, hair and teeth, and mean levels of 11.45 jug dl 9.94 figg and 6.80 jUg g respectively, were obtained. 

Unlike psychometric outcome measures, the need for quality control procedures in the analysis of biological materials has long been recognized, and the assurance of quality of analytical procedures is high. It was clear from discussions, however, that there were some areas within the analytical process, such as in physically cutting teeth for analysis, where there was room for variation and error, and which were not usually covered by the quality control procedures. 

---