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.     

Jensen's reaction-time investigations of intelligence: A critique

Jensen has reported a series of reaction-time studies which lead him to conclude that various parameters correlate significantly with IQ. Certain of these parameters are especially emphasized because of their theoretical background and the resulting theoretical light they shed upon the nature of intelligence. Two of the lime-lighted parameters are slope of RT across set size and increasing correlations of RT with IQ as set size increases. I review these studies in detail. I conclude that Jensen's claims are unwarranted. There are many difficulties in his approach that cover the entire gamut from method to data to theory. Some original reseach of my own is reported to illustrate the methodological problems with Jensen's procedure. The data that he alludes to often do not support his claims. The theory that he applies does not fit his paradigm. My conclusion: such research is not easy.     

Psychological effects of complex environments during the life span: A review and theory

This paper reviews evidence supporting a theory about the psychological effects of complex environments suggested by research on the causal relationships between occupational conditions and psychological functioning. The review indicates that environmental complexity leads to effective cognitive functioning across all stages of the life span. This effect has been found in both sexes, in several nations, and in species other than man. Although the evidence is not as extensive, environmental complexity also appears to lead to a self-directed rather than conformist orientation.     

A unifying model for the structure of intellectual abilities

Models of the structure of cognitive abilities suggested by Spearman, Thurstone, Guilford, Vernon and Cattell-Horn are reviewed. It is noted that some of the models include a general intellectual factor (g) while others do not. It is also noted that some models are nonhierarchical, while in others more narrow abilities are subsumed under broader abilities in a hierarchical pattern. An empirical study in which a test battery of 16 tests was administered to some 1000 subjects in the 6th grade is reported. Using the LISREL technique to test different models, good support is obtained for oblique primary factors in the Thurstone tradition as well as for the second-order factors fluid intelligence, crystallized intelligence, and general visualization hypothesized by Cattell and Horn. It is also found, however, that the second-order factor of fluid intelligence i is identical with a third-order g-factor. On the basis of these results a three-level model (the HILI-model) is suggested, with the g-factor at the top, two broad factors reflecting the ability to deal with verbal and figural information, respectively, at the second-order level, and the primary factors in the Thurstone and Guilford tradition at the lowest level. It is argued that most previously suggested models are special cases of the HILI-model.     

The intelligent infant: Theoretical implications

In the present essay, the fact that preferences for visual novelty during infancy are related to later performance on intelligence tests was interpreted to mean that intelligence is continuous from infancy. It was suggested that the bases of both continuity and the general factor in intelligence reside in the same small set of basic cognitive processes. It was also noted that intelligent behavior on the part of the infant raises a question about the relative importance of automatic and effortful processes in intelligence. The development of a valid test of infant intelligence was seen as an aid to clarifying the role of hereditary and environmental influences on intelligence and in furthering our understanding of mental retardation. In brief, the manner in which infants distribute their attention to novel and previously exposed stimuli reveals the origins of cognition. The origins of cognition are the origins of intelligence.     

Attenuated hypothesis or attenuated test of hypothesis?

After discussing several of the criticisms made by Professor Jensen, it is concluded that the Spearman hypothesis, as currently worded, has been disconfirmed. The near-zero correlation between blacks and low socio-economic status (SES) whites is not an artifact of the methodology. Neither is it a sampling fluke. The logic of sampling error does not apply to the arbitrary selection of intercorrelated tests from an undefined population. It is important also that low and high SES white differences are highly correlate with general factor loadings in a very heterogeneous selection of tests. Research attention should be turned to the difference in outcome of the race and SES comparisons.     

Recognition memory and intelligence

The assumption that individual differences in recognition memory are associated with individual differences in intelligence was explored by administering intelligence tests and tests of immediate visual recognition memory to a sample of 52 5-year-old children expected to vary widely from one another in intelligence. Each child was given the Peabody Picture Vocabulary Test (Form L) and two tests of immediate recognition memory: one test for 27 abstract patterns and one test for 27 unfamiliar cartoon faces. The mean PPVT-IQ for the sample was in the average range at 98.1. Interindividual variability in IQ proved to be high as reflected in the group SD of 22.6, with scores ranging from 40 to 136. The recognition tasks proved to be of moderate difficulty. Individual differences in memory for patterns were highly related to memory for faces (r = .76), indicating that the overall recognition test was reliable. The most important result of the present study was the strong association between recognition memory performance and PPVT-IQ of .70. The relation between recognition memory and IQ could not be accounted for by the inclusion of a few very low IQ children, since the association remained high at .61 when children with IQs below 75 were omitted from analysis. In short, the present results indicate that immediate recognition memory is highly associated with intelligence.     

Familiality estimates from restricted samples

In a recent paper here, Benbow, Zonderman, and Stanley (1983) report that the coefficient of regression of offspring IQ on parental IQ is much lower among the gifted than in the population at large. Thus, Benbow, Stanley, Kirk, and Zonderman conclude in a second paper, the gifted resemble their parents less than do people in general. In this paper, I show that this result is an artifact of the particular estimator of the regression coefficient employed by Bendoq, Zonderman, and Stanley. The leastsquares estimator, which they employ, is severely biased downward, if the sample on the dependent variable is restricted to the upper tail of the distribution, and this is precisely the nature of Benbow et al.'s sample. That is to say, in a bivariate normal distribution with constant regression coefficient, samples restricted to values of the dependent variable (here, child's IQ) above a certain value will always produce a lower regression coefficient than unrestricted samples drawn from the entire but same distribution. I introduce an unbiased estimator that can be calculated from the sample statistics reported in the Benbow, Zonderman, and Stanley article and find that the coefficient of regression of gifted child's IQ on parental IQ is, in fact, higher than the regression coefficients reported in the literature for unrestricted samples. That is, Benbow et al.'s data suggest that the gifted in fact resemble their parents more than do persons in general.     

Inspection time and its relation to intelligence

Inspection time, defined as the minimum duration for which two different stimuli must be presented if they are to be perceived as different, was measured for both auditory and visual stimuli. The minimum durations were determined by means of a two- alternative forced-choice task for 50 children whose average age was 12 years 2 months. The times were correlated with the children's verbal (Mill-Hill vocabulary) and nonverbal (Raven matrices) intelligence. The Kendall correlation coefficients were ?.3188 and ?.0929 for the auditory and visual inspection times with verbal intelligence, and ?.2322 and ?.2676 for those times with nonverbal intelligence. Auditory and visual inspection times were correlated .1721 with each other. These results do not support earlier claims that inspection time is closely related to conventional measures of intelligence.     

Ethnic group-by-generation interactions in WAIS scores in the Hawaii family study of cognition

This paper is a comparatively small-scale replication of a paper by DeFries, Corley, Johnson, Vandenberg, & Wilson (1982), using that subset of the DeFries subject group that was administered the Wechsler Adult Intelligence Scale (WAIS) and comparing parent vs. offspring performance of Americans of European and of Japanese Ancestry. Like DeFries et al., significant ethnic group-by-generation interactions were obtained in WAIS scores, suggesting the existence of substantial cultural influences on cognitive-test performance.     

The relationship of novelty preferences during infancy to later intelligence and later recognition memory

In the present study, a group of children originally tested for visual novelty preferences at 7 months and seen for estimates of intelligence at 3 years were revisited and tested for intellectual functioning and for visual recognition performance at 5 years. Prediction from performance at 7 months to intellectual functioning at 5 years was significant and remained at the same level as prediction from 7 months to 3 years (r = .42 at each point). In addition, it was shown that data on early novelty preferences could be combined with information on birth-order and parental education to achieve good prediction (R = .65) of five-year IQ scores. A further goal of the present study was to discover if infants' preferences for visual novelty, assumed to be an early measure of visual recognition memory would be more highly associated with later visual recognition performance or with later intellectual level. The results indicate that novelty preferences were more highly related to later intelligence quotients than to later recognition performance and such a pattern of relationships did not to be artificial.     

Group differences in intelligence and speed of information-processing

Three samples of different levels of mental ability, but each of average or above- average intelligence, were administered a battery of reaction time test which measure the speed with which persons can execute various elementary cognitive processes. Discriminant analyses revealed significant differences between the groups in reaction times and intraindividual standard deviations, and univariate analyses indicated that higher ability groups tended to obtain significantly faster mean reaction times and to show significantly less intraindividual variability than lower ability groups. Groups which differed the most in mental ability differed to the greatest extent on the more complex reaction time tests but this pattern was reversed for groups which were relatively close in mean IQ. Generally, the results support the hypothesis that speed- of-processing is an important factor unferlying intelligence, but a number of puzzling findings indicate the need for continued research in this area.     

Humphreys's attenuated test of Spearman's hypothesis

Humphreys's test of Spearman's hypothesis (viz., that the size of the standardized black-white differences on various psychometric tests is positively related to the tests' loadings on g, the general intelligence factor) is methodologically weak. It is based on comparison of a fairly representative sample of the black population of U.S. school children with a highly selected sample of the white school population, representing the lowest 15 to 20% of whites in socio-economic status (SES). A fair test of the hypothesis requires that the black and white samples should not be selected on any g-correlated variable, such as SES. Selection attenuates and distorts the relationship between tests' g loadings and the magnitude of the standardized mean black-white differences on the tests. Other unorthodox conditions in Humphreys's study, such as performing factor analysis on the test-score means of various arbitrary demographic groups instead of on individual test scores inflates tests' g loadings and biases the test of Spearman's hypothesis by restriction of reliable variance in g loadings. Humphreys's study cannot be considered a proper replication of Jensen's examination of Spearman's hypothesis in 11 different studies comprising 74 different tests, which consistently bears out Spearman's hypothesis.     

Absence of a sex difference in algorithms for spatial problem solving

Pairs of stimuli taken from a pscyhometric measure of spatial aptitude were shown to 36 college men and 32 college women. The stimuli in pairs were (a) either identical or mirror images, and (b) presented in orientations that differed by 0–135 deg. Individuals judged, as rapidly as possible, if the stimuli in a pair would be identical or mirror images if presented at the same orientation. Replicating previous work, there was a sex difference in the speed with which problems were solved. Of greater interest was the fact that men and women were quite alike in the frequency with which they used different algorithms to solve the problems. Most individuals solved the problems using an algorithm in which an individual encodes the stimuli in working memory, mentally rotates one stimulus to the orientation of the other, compares both determine if they are identical, and responds. Two variants of this algorithm were also used by some subjects. In one variant, if comparison revealed that the stimuli were dissimilar, individuals did not respond immediately but continued processing until a self- imposed deadline was reached. In another variation, subjects only rotated the comparison stimuli when their orientations exceeded a critical angle.     

Mental age and cognitive stage in young handicapped and at-risk children

This research addressed the question of whether stage-related patterns of early cognitive development, reported for normally developing children in the first two and a half years of life, may also characterize the development of at-risk and handicapped children when mental age rather than chronological age is used to organize the data. Performance on a psychometric infant test and two neo-Piagetian-based stage measures was assessed for 95 at-risk and handicapped children. Mental age predicted cognitive level of performance for levels 1 to 3, representing the first year and a half of development, but did not predict the highest level, symbolic functioning. In addition, transition points between levels were observed at mental ages similar to the chronological ages when these transitions have been reported for normally developing infants, for all but the last level. The significance of the correspondence between the psychometric measure and the stage measures is discussed and several alternatives for the breakdown at the highest level are considered.     

“Consistency” and “contradiction” in the development of gender role characteristics

There is currently an increasing amount of theoretical and empirical work arguing that stereotyped sex role behavior is maladaptive in our culture and that “androgyny” or “sex role transcendence” is a preferred mode of being. The latter, however, seems to require individual inconsistency and self-contradiction in behaviors and attitudes (since the individual is both active and passive, both independent and dependent, etc.). Theories of cognitive consistency maintain that individuals avoid self-contradiction and inconsistency, and therefore that androgyny runs counter to important motivational principles. This article examines this issue in some detail, and concludes that theories of cognitive dissonance and consistency reflect particular socio-cultural conditions rather than universal motivation principles. There is nothing inherently uncomfortable or “inconsistent” about androgyny and sex role transcendence.     

A critique of top-down independent levels models of speech production: Evidence from non-plan-internal speech errors

A number of speech errors are examined which are difficult to account for by top-down serial processing models of speech production which hove independent levels of processing. In particular, most of these errors are characterized by the presence of an interfering element which is external to the utterance under current construction. This paper has two main aims: to classify these errors, and to examine the constraints upon them. It is found that phonological similarity between the target and intrusion is a major determinant of error occurrence. The consequences for models of speech production are discussed in a framework consisting of the architecture and control structure of those models. A particular model to account for these data is proposed, consisting of a spreading activation lexical network.     

Predictability,controllability, and inoculation against learned helplessness

Nondepressed human subjects were divided into seven groups. On a series of discrimination problems, a helplessness group received insoluble problems, a solvable group received contingent feedback, and a no treatment control group received no feedback. For two other groups insoluble problems were preceded by success feedback on a different task presented according to a fixed ratio (FR) or variable ratio (VR) schedule of reinforcement. Two control groups received either FR or VR schedules of success but were not examined on the discrimination problems. All groups were tested for escape/avoidance performance on a human shuttle box. Both FR and VR schedules produced an inoculation against learned helplessness; escape performance by the helplessness group was significantly worse than that of FR and VR inoculation groups. These latter groups performed similar to the solvable and three control groups. Significantly worse than that of FR and VR inoculation groups. These latter groups performed similar to the solvable and three control groups. Significantly fewer subjects in the VR inoculation group exhibited avoidance responses than their counterparts in the FR inoculation group. despite similar escape performance. The findings indicate that learned helplessness can be prevented in humans and suggest different sources of interference produced by unpredictable and uncontrollable events.     

Measurement of adult performance on Piaget's water horizontality task

Three versions of Piaget's water-level-horizontality task (multiple choice, drawing, and apparatus tests) were administered to 121 female and 74 male adult volunteers. Sex differences and container orientation effects were replicated. Men were more accurate than women and horizontal and vertical container orientations evoked more accurate responses than oblique orientation. Reliability estimates ranged from .78 to .97 and correlations among the measures ranged from .78 to .88. The relative merits of alternative water-level testing and scoring methods and the orientation and type of stimuli to be used are discussed.