Cognitive clustering—How general? Loehlin, John C.
Intelligence (Norwood),
July-August 2019, 2019-07-00, 20190701, Letnik:
75
Journal Article
Recenzirano
Do “cognitive types”—groups of individuals with distinctive patterns of cognitive strengths and weaknesses—exist? The Texas Adoption Project (Horn & Loehlin, 2010) included 965 individuals with ...intelligence test subtest scores. Clusters formed from these individuals were compared with clusters found by others using the same intelligence test, and between subsamples in the present study—two random subsamples, two methods of clustering, two intelligence tests, the two sexes, and two generations. Moderate consistencies were found for the majority of the comparisons within the present sample. There was less cross-study agreement.
•Do discrete and dependable cognitive types exist?•Clusters were formed based on IQ subtest scores of 965 individuals from the Texas Adoption Project.•Comparisons were made with the results of other studies and for subgroups within this one.•Some consistencies were found for subgroups, but little across studies.
► Two studies disagreed on the existence of a general factor of personality (GFP). ► Using the methods of the one with the data of the other, a GFP was obtained. ► It held across broad and narrow ...scales and self- and others’ reports. ► Theories of the origin of a GFP were discussed.
Two recent analyses addressing the generality of a general factor of personality (GFP) across different personality inventories came to markedly different conclusions. By applying the methods used by the one that found a GFP to the data used by the one that did not, it was shown that a substantial GFP could be obtained in the latter case. It was also shown that similar GFPs could be derived from sets of more broadly or more narrowly defined questionnaire scales, or from self- and others’ reports on a given inventory. Finally, it was shown that a GFP defined from eight personality inventories showed a modest degree of correlation with criterion variables such as ratings by others and act-frequency clusters.
Adoption studies provide possibilities for estimating the extent to which prenatal environmental events account for individual differences on a trait. Correlations with birth mothers but not adoptive ...mothers suggest the presence of genetic or prenatal environmental effects; higher correlations with birth mothers than with birth fathers suggest the presence of the latter. Changes over time may also be relevant. The concepts involved are illustrated with parent–child IQ correlations from the Texas and Colorado Adoption Projects.
► Five factors beyond a general factor of personality (GFP) were studied. ► Data were from 8 personality inventories filled out by a large community sample. ► The GFP reflected social dominance, good ...adjustment, and intellectual achievement. ► The supplemental factors included agreeableness, conscientiousness, and openness. ► Both were related to others’ ratings, specific behaviors, and demographic variables.
The residual structure after removing a general factor of personality (GFP) was studied using 77 scales from 8 personality inventories completed by the Eugene-Springfield Community Sample. The GFP itself loaded scales consistent with social effectiveness, such as confidence, self-directedness, empathy, achievement, and low emotional distress. Five remaining factors were rotated orthogonally. They resembled several of the so-called Big Five dimensions, including Agreeableness, Conscientiousness, and Openness to experience. Both the GFP and the supplemental factors were related to others’ ratings of the respondents, participation in specific activities, and several demographic variables.
Genes, evolution, and personality Bouchard, Jr, T J; Loehlin, J C
Behavior genetics,
05/2001, Letnik:
31, Številka:
3
Journal Article
Recenzirano
There is abundant evidence, some of it reviewed in this paper, that personality traits are substantially influenced by the genes. Much remains to be understood about how and why this is the case. We ...argue that placing the behavior genetics of personality in the context of epidemiology, evolutionary psychology, and neighboring psychological domains such as interests and attitudes should help lead to new insights. We suggest that important methodological advances, such as measuring traits from multiple viewpoints, using large samples, and analyzing data by modern multivariate techniques, have already led to major changes in our view of such perennial puzzles as the role of "unshared environment" in personality. In the long run, but not yet, approaches via molecular genetics and brain physiology may also make decisive contributions to understanding the heritability of personality traits. We conclude that the behavior genetics of personality is alive and flourishing but that there remains ample scope for new growth and that much social science research is seriously compromised if it does not incorporate genetic variation in its explanatory models.
An interaction between socioeconomic status (SES) and the heritability of IQ, such that the heritability of IQ increases with higher SES, has been reported in some US twin studies, although not in ...others, and has generally been absent in studies outside the US (England, Europe, Australia). Is such an interaction present in US
adoption
studies? Data from two such studies, the Texas and the Colorado Adoption Projects, were examined, involving 238–469 adopted children given IQ tests at various ages. A mini multi-level analysis was made of the prediction of the IQs by the SES of the rearing home (a composite of parental education and occupation), by the birth mother’s intelligence, and by the interaction of the two. Neither study showed any substantial heritability × SES interaction: the effect size estimates in units comparable to twin moderation models were negative (− 0.042 and − 0.004), and the meta-analytic estimate for the combined analysis was − 0.27 (
SE
= 0.042) with a 95% confidence interval of − 0.109 to 0.054. Thus, while we cannot rule out positive moderation based on our two studies, the joint agreement across these studies, and with the non-US twin studies, warrants attention in further research. SES may not fully capture proximal familial-environmental aspects that moderate child IQ.
In a replication of Turkheimer, Haley, Waldron, D'Onofrio, Gottesman II (2003, Socioeconomic status modifies heritability of IQ in young children. Psychological Science, 14:623-628), we investigate ...genotype-environment (G x E) interaction in the cognitive aptitude of 839 twin pairs who completed the National Merit Scholastic Qualifying Test in 1962. Shared environmental influences were stronger for adolescents from poorer homes, while genetic influences were stronger for adolescents from more affluent homes. No significant differences were found between parental income and parental education interaction effects. Results suggest that environmental differences between middle- to upper-class families influence the expression of genetic potential for intelligence, as has previously been suggested by Bronfenbrenner and Ceci's (1994, Nature-nurture reconceptualized in developmental perspective: a bioecological model Psychological Review, 101:568-586) bioecological model.
•Lukaszewski has proposed a model to explain the General Factor of Personality.•The model is based on self-perceived Relative Bargaining Power.•Portions of this model were tested in a large community ...sample.•It fit the data, but with only limited explanatory power.
A model by Lukaszewski proposed that self-perceived relative bargaining power was the source of the mutual correlation among personality traits that underlies the so-called “general factor of personality.” Portions of Lukaszewski’s model were tested in a larger and broader data set than his, the Eugene-Springfield (Oregon) Community Sample. The model fit the data reasonably well, but the obtained values of its parameters suggested that relative bargaining power, at least as estimated here, would make only a weak contribution to a general factor of personality.
•Do personality traits mostly conform to lists or hierarchies?•Data: adjective ratings and scores on basic personality inventory scales.•Goldberg’s “bass-ackwards” method applied for series of 1–12 ...factors.•List- rather than hierarchy-type structure predominantly observed.
Are personality traits mostly related to one another in hierarchical fashion, or as a simple list? Does extracting an additional personality factor in a factor analysis tend to subdivide an existing factor, or does it just add a new one? Goldberg’s “bass-ackwards” method was used to address this question, based on rotations of 1–12 factors. Two sets of data were employed: ratings by 320 undergraduates using 435 personality-descriptive adjectives, and 512 Oregon community members’ responses to 184 scales from 8 personality inventories. In both, the view was supported that personality trait structure tends not to be strongly hierarchical: allowing an additional dimension usually resulted in a new substantive dimension rather than in the splitting of an old one, and once traits emerged they tended to persist.
The reported genetic correlation of 1.0 between the traits of procrastination and impulsivity (Gustavson, D. E., Miyake, A., Hewitt, J. K., & Friedman, N. P. (2014). Psychological Science), which was ...held to support an evolutionary origin of the relationship between the two traits, was tested in data from two large samples of twins from Australia. A genetic correlation of 0.299 was obtained. It was concluded that, although the presence of a genetic correlation between the two traits was supported, the modest magnitude of the correlation was such as to be consistent with many possible hypotheses, evolutionary and otherwise, about causal relationships between the traits in question.
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