On the possibility of the reemergence of a dysgenic trend with respect to intelligence in American fertility differentials

This paper examines the relationship between IQ and fertility in a sample of men and women aged 25–34 as of the late 1970s. This sample is of unusual interest for two reasons: (1) it is a national probability sample, representative of the non-institutional civilian population of the U.S. as a whole, and (2) it is for a post-World War II cohort. Most previous studies of the IQ/fertility relationship have employed nationally unrepresentative samples of cohorts born in the pre-war period, 1910–1940. The bias, in both time and place, of the samples used in these studies has not been adequately grasped by those who cite them as evidence of a eugenic trend with respect to intelligence.The major finding of these previous studies was that the IQ/fertility relationship is slightly positive, contrary to expectations though confirmatory of the so-called Eugenic Hypothesis. My working hypothesis is that this finding is special to the cohort chosen for study, i.e., one whose child-bearing took place during a period of rising birth rates (cohorts born between 1910 and 1940 were largely responsible for the baby boom after World War II). That is, in periods of rising birth rates, persons with higher intelligence tend to have fertility equal to, if not exceeding, that of the population as a whole. In periods of falling birth rates, the opposite is the case, according to my thesis.This thesis is generally supported by the data set described above. Fertility differentials to date within the post-World War II cohort, which entered its reproductive years during a period of falling birth rates, show a negative relationship between intelligence and fertility. The relationship is less negative for white men than for white women and for white women than for black women (black men are omitted from this study due to deficiencies in the data). The stated intentions of this cohort with respect to future fertility, if realized, will moderate the degree of this relationship, particularly for whites, but not change its sign.     

Feedback during exposure to inescapable shocks and subsequent shock-escape performance

In two experiments, we assessed the ability of a feedback stimulus during helplessness training to reduce the performance deficits common to inescapable shock. In each experiment, four groups of rats were exposed to either escapable shock (E), inescapable shock with a feedback stimulus following shock termination (Y-FS), inescapable shock with no feedback stimulus (Y-NFS), or no shock (N). The feedback stimulus eliminated the interference effects of inescapable shock when tested with an FR-3 lever press escape task (Experiment 1) or on an FR-1 task with a 3-s delay between the response and shock termination (Experiment 2). These results suggest that stress-induced biochemical changes may mediate the interference effects seen in inescapably shocked rats.     

Putting knowledge in its place: A scheme for programming parallel processing structures on the fly

This paper introduces a mechanism called CID, the Connection Information Distributor. CID extends connectionism by providing a way to program networks of simple processing elements on line, in response to processing demands. Without CID, simultaneous processing of several patterns has only been possible by prewiring multiple copies of the network needed to process one pattern at a time. With CID, programmable processing structures can be loaded with connection information stored centrally, as needed. To illustrate some of the characteristics of the scheme, a CID version of the interactive activation model of word recognition is described. The model has a single permanent representation of the connection information required for word perception, but it allows several words to be processed simultaneously in separate programmable networks. Multiword processing is not perfect, however. The model produces the same kinds of intrusion errors that human subjects make in processing brief presentations of word-pairs, such as SAND LANE (SAND is often misreported as LAND or SANE). The resource requirements of the mechanism, in terms of nodes and connections, are found to be quite moderate, primarily because networks that are programmed in response to task demands can be much smaller than networks that have knowledge of large numbers of patterns built in.     

Expectations,procedural justice,and alternative reactions to being deprived of a desired outcome

People often find that they do not have some positive outcome they once expected to obtain, while others around them have attained that outcome. Two experiments were conducted to assess how four possible responses to such a situation are affected by procedural justice (i.e., the fairness of the procedures by which the object was denied) and by one's expectations about obtaining the outcome in the future. The four possible responses examined were anger responses, achievement strivings, devaluation of the object (X), and self-deprecation. A repeated-measures analysis revealed that the dependent variables were differentially affected in Study 1, but less so in Study 2. Analyses further revealed effects of procedural justice, such that unfair procedures led to more anger, lower achievement strivings, greater devaluation of X, and (in Study 1 only) marginally less self-deprecation. Expectations had only a marginal affect on achievement strivings in Study 1, and an effect on self-deprecation in Study 2, with higher expectations leading to lower achievement strivings and less self-deprecation, respectively. Procedural justice and expectations interacted to affect subjects' derogation of the agent who deprived them (Study 1) and their devaluation of X (Study 2). Implications for future research and for theoretical development are discussed.     

Conditional reasoning following contradictory evidence: A developmental analysis

Recent evidence suggests that young adults do not correctly understand the logical relationship of the conditional (if p the q) as it applies to hypothesis testing, and most training procedures have not been productive. However, the introduction of contradictory evidence following faulty inferences has led to accurate inferences with conditional statements. Third and seventh grade and college studients (9, 13, and 21 years of age, respectively) were tested to assess developmental differences in improvement following contradiction training and to test whether improved performance transfers to other conditional reasoning tasks. Significant improvement in conditional reasoning was found for the young adult group following the introduction of contradictory evidence, and the positive effect of the treatment transferred across tasks. The third grade students showed no effects from the introduction of the contradiction, but the seventh graders were often confused by the introduction of the contradiction. Seventh grade and college student performances were generally worse than that of the third graders for the positive instances (p · q), but while the contradiction training improved college studients' performance it did not affect the seventh graders. The results are discussed in terms of changes in cognitive structures.     

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.     

Conditioned enhancement of human's liking for flavor by pairing with sweetness

This paper reports a procedure, like classical conditioning, that produces enhancement of liking for flavors by humans. The procedure is “pairing” of a relatively neutral flavor with sugar (a hedonically positive taste). Specifically, subjects drank 24 small samples of flavor A sweetened and 24 small samples of flavor B unsweetened. They were then tested for their liking for flavors A and B, both sweetened and unsweetened. In three different studies, varying in a number of aspects of stimulus presentations and context, a relative enhancement in liking for flavor A appeared both on the day of exposure and 1 week later. An absolute enhancement in liking of flavor B (a “mere exposure” effect) also occurred in two of the three experiments.     

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.     

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.     

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.     

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.     

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.     

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.     

Developmental trends in free classification: Evidence for a new conceptualization of perceptual development

Two studies are reported to explore the hypothesis that young children perceive integrally some stimuli that older children perceive separably. In both, kinder-garteners, second graders, and fifth graders (approximately 5, 8, and 11 years old) are required to classify sets of stimuli that vary in size and brightness. Triads are used in Experiment 1 and tetrads are used in Experiment 2. Also, in Experiment 2, second classifications, judgments of which classification is “best,” and verbal justifications for classifications are obtained. The general finding is that the kinder-garten data systematically implicate integrality of size and brightness while the fifth-grade data systematically implicate separability of size and brightness. The second-grade data are more ambiguous. Issues related to refining the developmental hypothesis and to extending its supportive data base are considered in a final discussion.     

An attempt to understand students' understanding of basic algebra

This paper reports the results obtained with a group of 24 14-year-old students when presented with a set of algebra tasks by the Leeds Modelling System, LMS. These same students were given a comparable paper-and-pencil test and detailed interviews some four months later. The latter studies uncovered several kinds of student misunderstandings that LMS had not detected. Some students had profound misunderstandings of algebraic notation: Others used strategies such as substituting numbers for variables until the equation balanced. Additionally, it appears that the student errors fall into several distinct classes: namely, manipulative, parsing, clerical, and “random.” LMS and its rule database have been enhanced as the result of this experiment, and LMS is now able to diagnose the majority of the errors encountered in this experiment. Finally, the paper gives a process-oriented explanation for student errors, and re-examines related work in cognitive modelling in the light of the types of student errors reported in this experiment. Misgeneralization is a mechanism suggested to explain some of the mal-rules noted in this study.     

Depression and achievement in subgroups of children with learning disabilities

Eighty-five learning disabled children were assigned to four subgroups and administered measures designed to assess the relationship between depression and academic achievement. As a group, these children were more depressed than nondisabled children. The subgroups, which were identified as learning disabled only, learning disabled with low IQ, learning disabled with socio-emotional disturbance, and learning disabled with hyperactivity, did not differ in magnitude of depression; however, the relationships between depression and achievement and IQ were substantially different in each subgroup. For the two largest subgroups, learning disabled only and learning disabled with socio-emotional disturbance, it was suggested that depression is the consequence of learning failure in the former and a possible cause of learning failure in the latter. These findings underscore the importance of depression, a heretofore neglected variable, for the understanding and remediation of learning disabilities.     

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.