Intelligence Tests

                                                        

Intelligence is defined as general cognitive problem-solving skills. A mental ability involved in reasoning, perceiving relationships and analogies, calculating, learning quickly… etc. 

An intelligence test is a test designed to determine the relative mental capacity of a person. (Intelligence Definition)

Ø  Theoretical Review:

Intelligence is defined as general cognitive problem-solving skills (Intelligence Definition). A mental ability involved in reasoning, perceiving relationships and analogies, calculating, learning quickly… etc. Earlier it was believed that there was one underlying general factor at the intelligence base (the g-factor), but later psychologists maintained that it is more complicated and could not be determined by such a simplistic method. Some psychologists have divided intelligence into subcategories. For example Howard Gardner maintained that it is comprised of seven components: musical, bodily-kinesthetic, logical-mathematical, linguistic, spatial, interpersonal, and intra personal. Other definitions are: “Intelligence is what you do when you don’t know what to do.” “Intelligence is a hypothetical idea which we have defined as being reflected by certain types of behavior.”

The measurement of intelligence is one of psychology’s greatest achievements and one of its most controversial (Nisbett, et al., 2012) . Critics complain that no single test can capture the complexity of human intelligence, all measurement is imperfect, no single measure is completely free from cultural bias, and there is the potential for misuse of scores on tests of intelligence. There is some merit to all these criticisms. But we would counter that the measurement of intelligence—which has been done primarily by IQ tests— has utilitarian value because it is a reasonably good predictor of grades at school, performance at work, and many other aspects of success in life (Gottfredson, 2004; Herrnstein & Murray, 1994). The German psychologist L. Wilhelm Stern was the first to coin the term intelligence quotient (IQ), a figure derived from the ratio of mental age to chronological age. Although Stern’s method for determining IQ is no longer in common use, the term IQ is still used today to describe the results in several different tests. Today, an average IQ score is considered to be 100, with deviations based on this figure. Intelligence tests do not measure creativity, character, personality, or other important differences among individuals, nor are they intended to. (Intelligence Definition)

Individuals rarely perform equally well on all the different kinds of items included in a test of intelligence (Neisser, 1995). One person may do relatively better on verbal than on spatial items, for example, while another may show the opposite pattern. Nevertheless, subtests measuring different abilities tend to be positively correlated: people who score high on one such subtest are likely to be above average on others as well. These complex patterns of correlation can be clarified by factor analysis, but the results of such analyses are often controversial themselves. Some theorists (e.g., Spearman, 1927) have emphasized the importance of a general factor, g, which represents what all the tests have in common; others (e.g., Thurstone, 1938) focus on more specific group factors such as memory, verbal comprehension, or number facility. One common view today envisages something like a hierarchy of factors with g at the apex. But there is no full agreement on what g actually means: it has been described as a mere statistical regularity (Thompson, 1939), a kind of mental energy (Spearman, 1927), a generalized abstract reasoning ability (Gustafsson 1984), or an index measure of neural processing speed (Reed & Jensen, 1992).

There have been many disputes over the utility of IQ and g (Neisser, 1995). Some theorists are critical of the entire psychometric approach (e.g., Ceci, 1990; Gardner, 1983; Gould, 1978), while others regard it as firmly established (e.g., Carroll, 1993; Eysenck, 1973; Hermstein & Murray, 1994; Jensen, 1972). The critics do not dispute the stability of test scores, nor the fact that they predict certain forms of achievement-especially school achievement--rather effectively (see Section 2). They do argue, however, that to base a concept of intelligence on test scores alone is to ignore many important aspects of mental ability. 

A wide range of environmental factors of biological nature influence intelligence (Nisbett, et al., 2012). Most of the known factors are detrimental, having to do with a lack of micronutrients and the presence of environmental toxins, and they were reviewed briefly by Neisser et al. (1996). Little of note concerning these effects has been uncovered since then, but there is not much research in this area. There is, however, one biological factor that seems to increase intelligence and that occurs early in life. Breastfeeding may increase IQ by as much as 6 points (Anderson, Johnstone, & Remley, 1999; Mortensen, Michaelsen, Sanders, & Reinisch, 2002) for infants born with normal weight and by as much as 8 points for those born prematurely (Anderson et al., 1999; Lucas, Morley, Cole, Lister, & Leeson-Payne, 1992), and the advantage seems to persist into adulthood (Mortensen et al., 2002).

The environmental differences that are associated with social class have a large effect on IQ (Nisbett, et al., 2012). We know this because adopted children typically score 12 points or more higher than comparison children (e.g., siblings left with birth parents or children adopted by lower SES parents), and adoption typically moves children from lower to higher SES homes. A meta-analysis available at the time of the Neisser et al. (1996) article found an effect of adoption of lower SES children by upper-middle-class parents of 12 points (Locurto, 1990).

Ø  List of Intelligence Tests (Berger, 2005):

·         Stanford-Binet Intelligence Scale, Fifth Edition (SBIS-V)

·         Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV)

·         Woodcock-Johnson III Tests of Cognitive Abilities 

·         Cognitive Assessment System (CAS)

·         Wechsler Adult Intelligence Scale (WAIS)

·         Comprehensive Test of Nonverbal Intelligence (CTONI)

·         Universal Nonverbal Intelligence Test (UNIT)

·         Kaufman Assessment Battery for Children (KABC)

·         Multidimensional Aptitude Battery

·         The Cognitive Abilities test 

·         Scholastic Assessment Tests

·         Culture Fair Intelligence Test