Intelligence and aptitudes

Aptitude and intelligence quotient are related, and in some ways opposite, views of human mental ability. Whereas intelligence quotient sees intelligence as being a single measurable characteristic affecting all mental ability, aptitude breaks mental ability down into many different characteristics which are supposed to be more or less independent of each other.

On the contrary, casual analysis with any group of test scores will nearly always show them to be highly correlated. The U.S. Department of Labor's General Learning Ability, for instance, is determined by combining Verbal, Numerical and Spatial aptitude subtests. In a given person some may be relatively low and others relatively high. In the context of an aptitude test the "high" and "low" scores are usually not far apart, because all ability test scores tend to be correlated. Aptitude is better applied intra-individually to determine what tasks a given individual is relatively more skilled at performing. Inter-individual aptitude differences are typically not very significant due to IQ differences. Of course this assumes individuals have not already been pre-screened for IQ through some other process such as SAT scores, GRE scores, finishing medical school, etc.


Aptitude Only batteries
Aptitudes are generally tested in the form of an aptitude battery which tests a large number of aptitudes at one time with a series of small tests for each aptitude. Aptitude batteries may lean more toward innate aptitudes or more toward learned skills. Aptitude batteries that lean toward aptitudes are often useful in selecting a career. The leading researchers and purveyors of aptitude tests are:

The Vocational Research Institute which produces a test used in schools and agencies that combines interest and aptitude for career guidance is Careerscope.
The Johnson O'Connor Research Foundation (JORF) is the original aptitude assessment organization. It produces the Johnson O'Connor Aptitude Battery (JOAB).
The Highlands Company is a spin-off of the Johnson O'Connor Research Foundation. It produces and the Highland Ability Battery.
The Ball Foundation produces the Ball Aptitude Battery.
Aptitude Inventory Measurement Service produces the AIMS Aptitude Battery.