The Wechsler Intelligence Scale for Children (WISC; Wechsler, 1974, 1976) is a frequently used instrument for the evaluation of intelligence. A comparison using the Wechsler Intelligence Scale for Children-Revised (WISC-R) and its new version, the WISC-III, is commonly made between the Verbal (V) and Performance (P) IQ profiles. In their study of delinquent adolescent males, Grace and Sweeney (1986) reported a mean P > V difference of 11.1 points for 14 1/2-year-olds versus 5.3 points for 17-year-olds. DeWolfe and Ryan (1984) found P > V profiles in 59% of the scores of the white sample compared with only 39% of the black sample. A number of variables, such as reading disabilities, race, age, gender, socioeconomic status, and even types of crimes committed, play an important role in these differences. The association of P > V with delinquent behavior is not strongly supported in adults or older adolescents who are affected by variables such as low levels of education and reading disabilities. However, in general, there is a strong trend associating delinquency with P > V in younger adolescents on the WISC and WISC-R (Kaufman, 1990).
Gross and Hubble (1998) described a field study in which the discrepancy between verbal and nonverbal skills among 150 male delinquents was assessed. It was found that the WISC-R Verbal/Performance IQ discrepancy showed up reliably more often among delinquents than among controls.
The importance of the WISC-R in the field of delinquency is apparent in a study conducted by Anderson and Walsh (1998), which investigated the predictability of adult criminal status. Stepwise discriminant function analysis was used to find the best subset of variables that would serve to distinguish between those with a serious criminal record and those without one. In order of importance, the four significant predictors were: (1) the WISC-R Comprehension subtest, (2) gender, (3) North American native, and (4) DQ+ from the Rorschach test.
Distinctions have also been examined in special populations, such as people with learning disabilities, delinquent groups, and ethnic groups, based on factors other than differences between Verbal IQ and Performance IQ. For example, Valencia, Rankin, and Oakland (1996) used the WISC-R factor-structure model to test Kaufman's (1990) three-factor solution. The model consisted of Verbal Comprehension (Factor 1), Perceptual Organization (Factor 2), and Freedom from Distractibility (Factor 3). The results showed the relevance of Kaufman's three-factor solution for ethnic groups. Anderson and Dixon (1995) tested one-, two-, three-, and four-factor models in normal and psychiatric inpatient adolescents to confirm the factor structure for the WISC-R. For both samples, the Kaufman three-factor solution had the best overall fit regarding the WISC-R subtest covariance structure.
The ACID profile (Arithmetic, Coding, Information, and Digit Span subtests) has been the traditional tool used to measure learning disabilities. There is a substantial amount of literature dealing with the ACID profile, some of which is controversial. Nonetheless, Wechsler (1991) found it to be a useful tool for this purpose. Reviews of research that has applied the WISC-R have reported that children with learning disabilities scored low on the original Freedom from Distractibility (FD) factor (Arithmetic, Coding, and Digit Span subtests) relative to other factors (Kaufman, 1990; Wielkiewicz, 1990), and on the ACID profile in comparison to other subtests (Joschko & Rourke, 1985). Sattler (1988) concluded that there is no unique WISC-R profile characteristic of all children with learning disabilities, and that the profile analysis should not be used in the diagnosis of learning disabilities.
School Dropouts in Israel
Israel, as with many other countries, faces the problem of school dropouts. These youngsters drop out of the formal education system before reaching tenth grade--the last year of compulsory education in Israel. …