The beginning of the measure of individual differences in "mental capacities" can be situated at the end of XIX century, and its development was based on two factors: the improvement of scientific psychology, and the universal and compulsory school attendance.
Some of the advances in psychology refered to the study and measurment of mental capacities were developed by German psychologists as Gustav Fechner and Hermann Ebbinghaus. Ebbinghaus did some investigations about memory and oblivion, while Fechner studied the relation between stimuli and sensations. Some of Fechner ideas were collected by Sir Francis Galton and were used later in the elaboration of a human habilities theory which was based on the existence of a "general mental hability"which…show more content… The result of this investigation was a scale which related mental and real age.
Charles Spearman was the English psychologist who performed the first factorial analysis. He studied the correlations of the tests elborated by Galton and Cattel and the results of differents tests applied to a sample set and with this analysis, he found out that the scores ́variance could be divided in two parts: a general one, common to every test and stimations, and another specific of each task. This descovery support the "general mental ability" theory postulated by Galton and allows its measurment.
The general cognitive factor (factor g) is a fundamental ability that intervenes in every mental operations, represents mental energy and has to do with every non-automatic task. It is a reflexion capacity which allows the subject to observe what is going on inside him/herself, to establish essential relations between two or more ideas and get the implicit initial ideas in a…show more content… Why does g matter?
Intelligence has been proved to be a relatively sable trait with a high heritability but a very low environmental depenency. It has a functional importance in life, it is necessary for reaching objectives and has nothing to do with morality, existence and utility.
For practical purposes, g is the ability to cope with cognitive complexity. Every single task in life requires some imformation processing, simple or complex. A higher g can deal with more complex situations and a lower g, with less complex ones, but there is always a minimum g; it is never zero and is stable across time.
Academic and practical intelligence.
It has been found in studies with business managers, college professors, elementary school sctudents, salespeople, college students and general populations that the practical intelligence is generally uncorrelated with academic intelligence as measured by conventional tests (Sternberg, Wagner, Williams, & Horvath, 1995). The lack of correlation between the two kinds of ability tests suggests that the best prediction of job performance will result when both academic and