The WISC-R factoral validity for minority groups and Spearman's hypothesis

The factoral structure of the WISC-R for groups of Anglo, Black, and Mexican-American children was compared and found to be highly similar across groups. The tests appear to be measuring the same abilities in all three groups. The order of subtest difficulty was not significantly correlated with the subtest g loadings for the Black children but was for the Mexican-Americans. These results provide support for Spearman's hypothesis with Mexican-American children.     

Spearman’s Law of Diminishing Returns and national ability

This research examined Spearman’s Law of Diminishing Returns (SLODR) using national ability as the unit of analysis. National ability was estimated using international standardized tests such as the Programme for International Student Assessment (PISA), Trends in International Mathematics and Science Study (TIMSS), and Progress in International Reading Literacy Study (PIRLS). Factor analysis estimated the national G loadings of tests for high and low ability nations. Consistent with SLODR, the G loadings of tests were lower for higher ability nations. The pattern was confirmed after correcting for school attendance and age biases. Because a test’s g loading is directly related to its predictive validity (correlation with outcomes), our results imply that the predictive validity of tests may be lower for higher ability nations.     

Comparison of black-white differences on the WISC-R and the K-ABC: Spearman's hypothesis

The Kaufman Assessment Battery for Children (K-ABC) and the Wechsler Intelligence Scale for Children-Revise (WISC-R) are compared with respect to the magnitudes of the average white-black differences in standardized scaled scores and in raw scores. The two test batteries were administered to a sample of 172 fourth- and fifth-grade children comprising 86 black-white pairs matched on age, sex, school, and socioeconomic status. The K-ABC and WISC-R are highly correlated, and the general factor, or g, of one battery is virtually identical to the g of the other. The high positive correlation between the size of the white-black difference on the various subtests of both batteries and the subtests' loadings on the g factor bears out Spearman's hypothesis that a test's white-black dicriminability is a direct function of the test's g loading. The lesser white-black discriminability of the K-ABC relative to the WISC-R is attributable to (1) the smaller g loadings of the K-ABC subsets and (2) the presence of other factors, particularly sequential short-term memory which, to some degree, offsets the white-black difference in g.     

Relations between mental performance and reaction time: New aspects of an old problem

The relation between simple and complex reaction time and psychometrically determined mental performance was reexamined with 486 subjects of above-average intelligence. Various standardized tests measuring aspects of cognitive ability, memory and ability to concentrate were used. Simple and complex reaction times were measured using the Klebelsberg modification of the Mierke apparatus. Correlations between complex reaction time and mental performance as observed by other investigators were mostly confirmed. We found, however, the strongest and most consistent correlations with tests measuring short-term memory; ability to concentrate and spatial ability. On the other hand, tests known and shown again in this paper to load highly on Spearman's general factor g, such as verbal abilities; combinatoric thinking; abstraction; or calculation gave only trivial, and, in most cases, nonsignificant correlations with complex reaction time. We even observed a negative (though, for our data, not significant) correlation between g-loadings of subtests and their correlations with complex reaction time for the only complete standardized intelligence test used in this study, the “Intelligenz-Strukturtest (Amthauer).” Therefore, this study does not support the hypothesis that fast processing of complex information as measured by complex reaction time is the decisive component of the general factor of intelligence g.     

The factorial similarity of the WISC-R performance Scale in deaf and hearing samples

Wechsler Intelligence Scale for Children—Revised (WISC-R) Performance Scale metrics and subtest factor loadings, derived separately from deaf (N = 1228) and hearing (N = 2200) samples, are practically identical. Small mean differences are probably attributable to the higher incidence of brain damage among deaf children. In addition to demonstrating the absence of construct bias in WISC-R Performance IQ (PIQ) measurement for deaf children, the results contradict theories which propose linguistic bias as the cause of the white-black difference in Performance IQ. Spearman's hypothesis that white-black mental test differences are primarily a difference in g received significant support. The results indicate that cognition, as measured by PIQ, is virtually independent of language acquisition.     

Extending Holland's theory to adult women

The potential of Holland's theory for use in the vocational guidance of adult women depends in part on more validity data with regard to the conceptual meaningfulness of the constructs. This study reports the findings of a correlative analysis between scores on Holland's Vocational Preference Inventory (VPI), which measures the six “styles”, and selected scales on four criterion tests predicted in advance to be related to the VPI. The findings for this sample of adult women indicate strong evidence for the validity of the Intellectual, Conventional and Enterprising “styles”, but questions are raised with regard to the meaningfulness of the Realistic, Social, and Artistic types.     

Trait anxiety,stress, and learning a test of Saltz's hypothesis

Behavioral predictions from Saltz's, Spence's, and Spielberger's interpretations of trait anxiety were tested in a complex verbal learning task. Fifty-three high-anxious and 52 low-anxious male college students were randomly distributed to test conditions of failure-stress, pain-stress, or neutral instructions. The learning data revealed that high-anxious-failure and low-anxious-pain Ss were disrupted and supported Saltz's hypothesis; self-reported anxiety (A-State scale, STAI) was observed only in high-anxious-failure Ss and supported Spielberger's theory of the arousal of state anxiety as a function of trait anxiety. However, the contradiction between self-reported anxiety and learning behavior in low-anxious-pain Ss indicated that the verbal report of these Ss was an inaccurate or insensitive index of arousal.     

Rushton’s contributions to the study of mental ability

This essay describes Rushton’s contribution to examining the nexus of intelligence, race, and genetics, specifically what I termed “Spearman’s hypothesis”. It states that Black–White differences are “most marked in just those [tests] which are known to be saturated with g”. I (Jensen) had confirmed this hypothesis using large data sets in the 1970s and 1980s and also found that Black–White differences were most marked on the more heritable rather than the more cultural subtests. Rushton confirmed and extended these findings in many highly innovative ways and demonstrated Spearman’s hypothesis applied among samples of Gypsy Roma in Serbia, and East Asian, European, South Asian, Colored and Black samples in South Africa. He has not only documented group differences in brain size, intelligence, life span, family structure, infant mortality, developmental precocity, personality, and temperament, and rates of two egg twinning, and crime among East Asians, Europeans, and Africans, but also provided a life history theory that explains them.     

Developmental inter-relationships among concrete operational tasks: An investigation of Piaget's stage concept

One hundred and one primary school children were tested on eight concrete operational tasks. Each child's performance on each task was classified as either preoperational, transitional, or fully operational. Cross-classification tables were constructed showing the joint classification of children's performance on all possible pairs of the eight tasks. Two models of intertask relations, Wohlwill's (The study of behavioral development. New York: Academic Press, 1973) divergent-decalage and reciprocal-interaction patterns, were evaluated for their fit to the cross-classification data using χ² goodness-of-fit procedures. Instances of both these patterns were identified in the data. The findings give some support to Flavell and Wohlwill's modification of Piaget's stage concept, in which individual groupings (e.g., seriation) are the structural basis of the interrelationships among concrete operational tasks. Tasks based on the same rule showed a degree of developmental interdependence (reciprocal-interaction patterns), while tasks based on different rules appeared to develop independently (divergent-decalage patterns). However, only one-half of the cross-classification tables were adequately described by either the divergent-decalage or the reciprocal-interaction patterns.     

The dependability of the general factor of intelligence: Why small, single-factor models do not adequately represent g

Floyd, Shands, Rafael, Bergeron and McGrew (2009) used generalizability theory to test the reliability of general-factor loadings and to compare three different sources of error in them: the test battery size, the test battery composition, the factor-extraction technique, and their interactions. They found that their general-factor loadings were moderately to strongly dependable. We replicated the methods of Floyd et al. (2009) in a different sample of tests, from the Minnesota Study of Twins Reared Apart (MISTRA). Our first hypothesis was that, given the greater diversity of the tests in MISTRA, the general-factor loadings would be less dependable than in Floyd et al. (2009). Our second hypothesis, contrary to the positions of Floyd et al. (2009) and Jensen and Weng (1994), was that the general factors from the small, randomly-formed test batteries would differ substantively from the general factor from a well-specified hierarchical model of all available tests. Subtests from MISTRA were randomly selected to form independent and overlapping batteries of 2, 4 and 8 tests in size, and the general-factor loadings of eight probe tests were obtained in each battery by principal components analysis, principal factor analysis and maximum likelihood estimation. Results initially indicated that the general-factor loadings were unexpectedly more dependable than in Floyd et al. (2009); however, further analysis revealed that this was due to the greater diversity of our probe tests. After adjustment for this difference in diversity, and consideration of the representativeness of our probe tests versus those of Floyd et al. (2009), our first hypothesis of lower dependability was confirmed in the overlapping batteries, but not the independent ones. To test the second hypothesis, we correlated g factor scores from the random test batteries with g factor scores from the VPR model; we also calculated special coefficients of congruence on the same relation. Consistent with our second hypothesis, the general factors from small non-hierarchical models were found to not be reliable enough for the purposes of theoretical research. We discuss appropriate standards for the construction and factor analysis of intelligence test batteries.     

Analysis of the development of children's spatial reference systems

Four, six, and ten-year-old children were required to copy an object's location and orientation within a two-dimensional spatial layout under two conditions: when both E's standard board and that of the S's were in the same orientation and when they were rotated 180 ° from each other. The failure of the 4-yr-olds to copy location and orientation under both conditions even when space was topographically coded indicates that at this age the child does not conceptualize space within two dimensions. Although the errors of the 4-yr-olds tended to be of a self-reference nature with respect to orientation and location on rotation trials the axes of the self-reference system were not coordinated. Six and 10-yr-old children performed significantly better on both conditions, with the exceptions that the 6-yr-olds continued to preserve some orientations within a self-reference system. When topographical codes were removed and S imagined rotation there were no significant age differences in total errors; however, older children organized entire subspaces within a self-reference system. The findings support Piaget and Inhelder's hypothesis that two-dimensional reference systems do not develop until the period of concrete operational thought, and they also indicate that even at age 10, the self-reference system continues to function when topographical codes are absent. Several cognitive mechanisms proposed to account for the development of spatial abilities are critically discussed.     

White–black differences in g and non-g effects for the SAT and ACT

This research examined g and non-g effects for the SAT and ACT for whites and blacks. SAT scores, ACT scores, and college GPAs were obtained from the National Longitudinal Survey of Youth. g was estimated using the Armed Services Vocational Aptitude Battery. Results indicated that (a) the g loadings of SAT and ACT composite scores were lower for whites than blacks, (b) group differences in the g loadings were related to the math subtests of the SAT and ACT, and (c) non-g variance accounted for surprisingly large percentages of SAT–GPA and ACT–GPA relations (range = 37–67%). The findings are discussed in terms of Spearman’s Law of Diminishing Returns.     

The impact of sociocultural background and assessment data upon school psychologists' decisions

Fifty-six school psychologists participated in an adapted version of Algozzine and Ysseldyke's (1981) diagnostic simulation. The adaptation was designed to investigate the effects of sociocultural background (rural vs. suburban) and assessment data (normal vs. LD) on school psychologists' educational decisions. Knowledge of a student's sociocultural background did not influence these school psychologists' decisions; however, the type of assessment data had a strong impact. In contrast to the findings of Algozzine and Ysseldyke, the subjects did not ignore individual test data in favor of teacher referral statements. The school psychologists who received normal data were less likely to have low expectations for pupils' future academic attainment, to diagnose the child as LD, and to recommend special class placement. The subject school psychologists' perceptions of the importance of various diagnostic factors also agreed with their actual practices, as they reported that standardized test data figured prominently in their decision making. In short, this research suggests that school psychologists utilize multiple sources of information but rely primarily upon the more objective sources of information to make educational decisions.     

Deep and surface structure in children's sentence learning

Fifth-graders were asked to learn 32 syntactically varied, semantically unrelated sentences containing combinations of agentive, objective and instrumental case relations. Five learning trials, each followed by a noun-prompted recall test, were provided. Recall patterns indicated that variations in surface structure complexity (i.e., verb voice and sentential position of noun prompts) exerted less influence on Ss' memory for sentences than deep structures. Several trials were required for Ss to reproduce syntactic details accurately and many transformational errors were observed. Even then, children were unable to learn one syntactic form. Although patterns of recall were more consistent with deep structure predictions, results were not completely supportive of Fillmore's analysis of deep structure in terms of case relations, and the possibility that other non-linguistic means were used to store sentences loomed as an alternative to the deep structure view.     

Black–White differences on the g-factor in South Africa: a “Jensen Effect” on the Wechsler Intelligence Scale for Children — revised

A test is made to determine whether South African Black–White differences on various tests of cognitive performance are like the Black–White differences in the United States in being positively associated with a test's g loadings, where g is the general factor of intelligence. Data are analyzed from Skuy, Schutte, Fridjhon and O'Carroll [Skuy, M., Schutte, E., Fridjhon, P., & O'Carroll, S. (2001). Suitability of published neuropsychological test norms for urban African secondary school strudents in South Africa. Personality and Individual Differences, 30, 1413–1425) of 154 13- to 15-year-old secondary school students in Soweto, Johannesburg, on the Wechsler Intelligence Scale for Children–Revised (WISC-R). The more highly correlated a sub-test was with g, the more it predicted the African–White difference (r =0.77, p=0.05). The effect remained even when the Vocabulary sub-test was excluded or when g was extracted from the Black rather than from the White standardization sample (r=0.60, P<0.05), as it did as well if Spearman's rho was used instead of Pearson's r (g from Whites=0.74, g from Blacks=0.74, P< 0.005). Understanding observed Black–White differences around the world requires new research on the nature and nurture of g.     

Emotional and developmental aspects of human figure drawings in predicting school readiness

It was hypothesized that the combined use of Koppitz' developmental and emotional scores can improve the prediction of school readiness from children's Human Figure Drawings (HFD) when compared with each measure separately. The relationship of SES to HFD scores was also investigated. Multiple regression analysis was used with four factors—developmental score, emotional score, sex of the child, and SES of the school— to derive comparative correlations to test the hypotheses and to create a prediction equation to estimate the Metropolitan Readiness Test (MRT) scores of 141 kindergarten students ages 5 to 6 years representing three SES levels. Hit rate data were also presented. The results showed that the correlation for the combined developmental and emotional scores with the MRT score was not different than their separate correlations with the MRT. The SES factor was found to be significantly correlated (p < .01) with both developmental and emotional scores. The best single variable predictor of MRT scores was SES. The application of Bayes' Theorem of probability to the hit rate data showed that the nonreadiness predictions yielded by the developmental score, emotional score, and their combination are not better than chance predictions. Thus, it was found that Koppitz' developmental or emotional scoring systems are not viable screening instruments.     

An examination of project aware: The effects on children's attitudes toward themselves,others, and school

The purpose of this study was to determine the impact of Project AWARE on children's attitudes about themselves, peers, teachers, principals, and school. Data were collected on children's sex, race, stanine score on achievement tests, and pretest performance in order to determine the differential effects of the treatment. Eighty students were included in the study, 40 in the experimental group and 40 in the control group. All were from fourth and fifth grade classrooms. The major findings were that children involved in the program achieved greater personal adjustment and accepted responsibility for negative outcomes in social situations (internal control). White children scored higher in personal and social adjustment. Black children evidenced more positive attitudes toward school. Girls scored significantly higher than boys on the social adjustment subtests and attitudes toward peers. Black children in the control group had less positive attitudes toward teachers than white children in the experimental group     

Concurrent validity of Holland's theory for non-college-degreed black women

This study, using the Vocational Preference Inventory (VPI) and the Self-Directed Search (SDS), explored the concurrent validity of Holland's theory for employed non-college-degreed black women. The VPI and the SDS were administered to 102 black women workers in occupational environments consistent with Holland's six vocational environments. The results revealed that four scales of the VPI and four scales of the SDS successfully differentiated the occupational groups consistent with Holland's theoretical notions. In general, the findings lend some support to the concurrent validity of Holland's theory for employed non-college-degreed black women.     

Concurrent validity of Holland's theory for college-degreed black women

This study, using the Vocational Preference Inventory (VPI) and the Self Directed Search (SDS), explored the concurrent validity of Holland's theory for employed college-degreed black women. The VPI and SDS were administered to 93 black women workers in occupational environments consistent with Holland's six vocational environments. The results revealed that four scales of the VPI and five scales of the SDS successfully differentiated the occupational groups consistent with Holland's theoretical notions. In general, the findings lend some support to the concurrent validity of Holland's theory for employed college-degreed black women.     

Race differences and the Spearman hypothesis

Certain published data have been reviewed and new data presented relevant to the so-called Spearman hypothesis concerning the racial differences on cognitive tests of black and white Americans. In the published data, the correlation between the profiles of low socio-economic and high socio-economic status (SES) whites became ?.90 when sex, area of the country, and grade/age were controlled. This nearly mirror-image relationship suggests that the residual across-the-board difference between the two groups is primarily on the general factor in intelligence. In contrast, the same correlation between blacks and the low SES whites was only ?.19. This indicated not only independence of the profiles but the presence of multiple causes of differences in addition to a possible contribution of the general factor. These published interpretations have now been confirmed by obtaining correlations between general factor loadings and the group differences for most of the same tests. For the SES dochotomy in whites this correlation is .86. For blacks and the low SES whites it is .17. When the two distributions of differences are correlated, a value of .42 is obtained. The Spearman hypothesis appears to apply primarily to differences in socio-economic status rather than race. Furthermore, one cannot assume a large genetic component for each set of differences. Nor can one argue that the possibility of a large environmental component for each set indicates common environmental causes.