Incorporating general intelligence into epidemiology and the social sciences

Wrecked by Success? Not to Worry

We examined the wrecked-by-success hypothesis. Initially formalized by Sigmund Freud, this hypothesis has become pervasive throughout the humanities, popular press, and modern scientific literature. The hypothesis implies that truly outstanding occupational success often exacts a heavy toll on psychological, interpersonal, and physical well-being. Study 1 tested this hypothesis in three cohorts of 1,826 high-potential, intellectually gifted individuals. Participants with exceptionally successful careers were compared with those of their gender-equivalent intellectual peers with more typical careers on well-known measures of psychological well-being, flourishing, core self-evaluations, and medical maladies. Family relationships, comfort with aging, and life satisfaction were also assessed. Across all three cohorts, those deemed occupationally outstanding individuals were similar to or healthier than their intellectual peers across these metrics. Study 2 served as a constructive replication of Study 1 but used a different high-potential sample: 496 elite science/technology/engineering/mathematics (STEM) doctoral students identified in 1992 and longitudinally tracked for 25 years. Study 2 replicated the findings from Study 1 in all important respects. Both studies found that exceptionally successful careers were not associated with medical frailty, psychological maladjustment, and compromised interpersonal and family relationships; if anything, overall, people with exceptionally successful careers were medically and psychologically better off.

Do cognitive styles affect vaccine hesitancy? A dual-process cognitive framework for vaccine hesitancy and the role of risk perceptions

RATIONALE

In this study, we consider cognitive differences in vaccine hesitancy and how perceived risks intervene in this relationship. Recent research agrees on the existence of two cognitive processes, intuitive and analytic cognition. Different individuals lean toward one of these processes with varying degrees of strength, influencing day-to-day behavior, perceptions, and decisions. Thinking dispositions might influence, at the same time, vaccine acceptance and perceived risks of vaccine-preventable disease, but the implications of individuals' cognitive differences for vaccination uptake have seldom been addressed from a sociological standpoint.

OBJECTIVE

We bridge this gap by adopting a dual-process framework of cognition and investigate how thinking styles have a direct association with vaccine hesitancy and an indirect one through perceptions of risk.

METHODS

We use data from original surveys carried out between September and November 2019 on a sample of the Italian population, participating in an online panel run by a major Italian survey company. We use Karlson, Holm, and Breen (KHB) decomposition to compare coefficients of nested-nonlinear models, separate the direct and indirect association of cognitive processes with vaccine hesitancy, and disentangle the contribution of each measure of risk perception.

RESULTS

Net of individual socio-demographic characteristics, intuitive thinking is positively associated with the likelihood of being vaccine hesitant, and this direct association is as important as the indirect one through risk perceptions. Affective risk perceptions account for over half of the indirect association, underlining the centrality of affective versus probabilistic approaches to risk perception.

CONCLUSION

This study contributes to the existing literature by highlighting the importance of including cognitive characteristics in vaccine hesitancy research, and empirically showing individuals' qualitatively complex perceptions of risks. Taking into account individuals' preferred cognitive style and affective concerns might be important in developing better tailored communication strategies to contain vaccine hesitancy.

Personality traits and investor profile analysis: A behavioral finance study

This study investigates which of four paradigms best portrays the risk profile manifest by investors in their financial asset investment decisions. The paradigms used to explain this profile were: prospect theory, investor profile analysis (IPA), the Big Five Personality Test, and the Cognitive Reflection Test (CRT). The choice of proxy for the risk preferences (profile) of a typical investor was defined by simulating investments in a laboratory setting. The results are analyzed using ordered logistic regression and show that people who have greater risk tolerance according to IPA, who violate prospect theory, and who have a high degree of openness to experience have the greatest probability of taking higher levels of risk in their investment decisions. With regard to the CRT, higher numbers of correct responses in this test has an inverse relationship with risk taking.

Intelligence as a Developing Function: A Neuroconstructivist Approach

The concept of intelligence encompasses the mental abilities necessary to survival and advancement in any environmental context. Attempts to grasp this multifaceted concept through a relatively simple operationalization have fostered the notion that individual differences in intelligence can often be expressed by a single score. This predominant position has contributed to expect intelligence profiles to remain substantially stable over the course of ontogenetic development and, more generally, across the life-span. These tendencies, however, are biased by the still limited number of empirical reports taking a developmental perspective on intelligence. Viewing intelligence as a dynamic concept, indeed, implies the need to identify full developmental trajectories, to assess how genes, brain, cognition, and environment interact with each other. In the present paper, we describe how a neuroconstructivist approach better explains why intelligence can rise or fall over development, as a result of a fluctuating interaction between the developing system itself and the environmental factors involved at different times across ontogenesis.

Reaction Time Explains IQ's Association with Death

Lower IQ is associated with earlier death, but the cause of the relationship is unknown. In the present study, psychometric intelligence and reaction times were both significantly related to all-cause mortality in a representative sample of 898 people aged 56 years who were followed up with respect to survival until age 70. The association between IQ and mortality remained significant after adjusting for education, occupational social class, and smoking, all of which have been hypothesized as confounding variables. The effect of IQ on mortality was not significant after adjusting for reaction time, suggesting that reduced efficiency of information processing might link lower mental ability and earlier death. This new field of cognitive epidemiology provides arguably the strongest evidence for the importance of psychological factors in physical health and human survival. Finding the mechanisms that relate psychometric intelligence to mortality might help in formulating effective interventions to reduce inequalities in health.

Tracking Exceptional Human Capital Over Two Decades

Talent-search participants (286 males, 94 females) scoring in the top 0.01% on cognitive-ability measures were identified before age 13 and tracked over 20 years. Their creative, occupational, and life accomplishments are compared with those of graduate students (299 males, 287 females) enrolled in top-ranked U.S. mathematics, engineering, and physical science programs in 1992 and tracked over 10 years. By their mid-30s, the two groups achieved comparable and exceptional success (e.g., securing top tenure-track positions) and reported high and commensurate career and life satisfaction. College entrance exams administered to intellectually precocious youth uncover extraordinary potential for careers requiring creativity and scientific and technological innovation in the information age.

Women's fertility across the cycle increases the short-term attractiveness of creative intelligence

Male provisioning ability may have evolved as a "good dad" indicator through sexual selection, whereas male creativity may have evolved partly as a "good genes" indicator. If so, women near peak fertility (midcycle) should prefer creativity over wealth, especially in short-term mating. Forty-one normally cycling women read vignettes describing creative but poor men vs. uncreative but rich men. Women's estimated fertility predicted their short-term (but not long-term) preference for creativity over wealth, in both their desirability ratings of individual men (r=.40, p<.01) and their forced-choice decisions between men (r=.46, p<.01). These preliminary results are consistent with the view that creativity evolved at least partly as a good genes indicator through mate choice.

Study of Mathematically Precocious Youth After 35 Years: Uncovering Antecedents for the Development of Math-Science Expertise

This review provides an account of the Study of Mathematically Precocious Youth (SMPY) after 35 years of longitudinal research. Findings from recent 20-year follow-ups from three cohorts, plus 5- or 10-year findings from all five SMPY cohorts (totaling more than 5,000 participants), are presented. SMPY has devoted particular attention to uncovering personal antecedents necessary for the development of exceptional math-science careers and to developing educational interventions to facilitate learning among intellectually precocious youth. Along with mathematical gifts, high levels of spatial ability, investigative interests, and theoretical values form a particularly promising aptitude complex indicative of potential for developing scientific expertise and of sustained commitment to scientific pursuits. Special educational opportunities, however, can markedly enhance the development of talent. Moreover, extraordinary scientific accomplishments require extraordinary commitment both in and outside of school. The theory of work adjustment (TWA) is useful in conceptualizing talent identification and development and bridging interconnections among educational, counseling, and industrial psychology. The lens of TWA can clarify how some sex differences emerge in educational settings and the world of work. For example, in the SMPY cohorts, although more mathematically precocious males than females entered math-science careers, this does not necessarily imply a loss of talent because the women secured similar proportions of advanced degrees and high-level careers in areas more correspondent with the multidimensionality of their ability-preference pattern (e.g., administration, law, medicine, and the social sciences). By their mid-30s, the men and women appeared to be happy with their life choices and viewed themselves as equally successful (and objective measures support these subjective impressions). Given the ever-increasing importance of quantitative and scientific reasoning skills in modern cultures, when mathematically gifted individuals choose to pursue careers outside engineering and the physical sciences, it should be seen as a contribution to society, not a loss of talent.

Incremental validity of WISC-IV(UK) factor index scores with a referred Irish sample: predicting performance on the WIAT-II(UK.)

BACKGROUND

Subtest and factor scores have typically provided little incremental predictive validity beyond the omnibus IQ score.

AIMS

This study examined the incremental validity of Wechsler Intelligence Scale for Children - Fourth UK Edition (WISC-IV(UK) ; Wechsler, 2004a, Wechsler Intelligence Scale for Children - Fourth UK Edition, Harcourt Assessment, London, UK) and factor index scores in predicting academic achievement on the Wechsler Individual Achievement Test - Second UK Edition (WIAT-II(UK) ; Wechsler, 2005a, Wechsler Individual Achievement Test-Second UK Edition, Pearson, London, UK), beyond that predicted by the WISC-IV(UK) FSIQ.

SAMPLE

The sample included 1,014 Irish children (ages 6-0 to 16-9) who were referred for evaluation of learning difficulties.

METHOD

Hierarchical multiple regression analyses were used with the WISC-IV(UK) FSIQ (Block 1) and factor index scores (Block 2) as predictors and WIAT-II(UK) subtest and composite scores as dependent variables.

RESULTS

The WISC-IV(UK) FSIQ accounted for statistically significant and generally large portions of WIAT-II(UK) subtest and composite score variance. WISC-IV(UK) factor index scores combined to provide statistically significant increments in prediction of most WIAT-II(UK) subtest and composite scores over and above the FSIQ; however, the effect sizes were mostly small as previously observed (i.e., Canivez, 2013a, Psychol. Assess., 25, 484; Glutting et al., 2006, J. Spec. Educ., 40, 103; Nelson et al., 2013, Psychol. Assess., 25, 618). Individually, the WISC-IV(UK) factor index scores provided small unique contributions to predicting WIAT-II(UK) scores.

CONCLUSION

This, in combination with studies of apportioned variance from bifactor confirmatory factor analysis (Watkins et al., 2013, Int. J. Sch. Educ. Psychol., 1, 102), indicated that the WISC-IV(UK) FSIQ should retain the greatest weight in WISC-IV(UK) interpretation.

Deliberative and spontaneous cognitive processes associated with HIV risk behavior

Dual process models of decision-making suggest that behavior is mediated by a spontaneous behavior selection process or by a more deliberative evaluation of behavioral options. We examined whether the deliberative system moderates the influence of spontaneous cognition on HIV-risk behaviors. A measure of spontaneous sex-related associations (word association), a measure of deliberative working memory capacity (operation span), and two measures of sexual behavior (condom use and multiple partners) were assessed in a cross-sectional study among 490 adult drug offenders. Significant effects were observed among men but not among women in two latent interaction models. In a novel finding, the accessibility of spontaneous safe sex-related associations was significantly more predictive of condom use among men with higher working memory capacity than among men with lower capacity. These results have implications for the design of interventions to promote safe sex practices.

An evaluation of analytical approaches for understanding change in cognition in the context of aging and health

OBJECTIVES

In this article, we discuss the importance of studying the relationship between health and cognitive function, and some of the methods with which this relationship has been studied.

METHODS

We consider the challenges involved, in particular operationalization of the health construct and causal inference in the context of observational data. We contrast the approaches taken, and review the questions addressed: whether health and cognition are associated, whether changes in health are associated with changes in cognition, and the degree of interdependency among their respective trajectories.

RESULTS

A variety of approaches for understanding the association between cognition and health in aging individuals have been used. Much of the literature on cognitive change and health has relied on methods that are based at least in part on the reorganization of between-person differences (e.g., cross-lag analysis) rather than relying more fully on analysis of within-person change and joint analysis of individual differences in within-person change in cognition and health.

DISCUSSION

We make the case for focusing on the interdependency between within-person changes in health and cognition and suggest methods that would support this.

Exceptional cognitive ability: the phenotype

Characterizing the outcomes related to the phenotype of exceptional cognitive abilities has been feasible in recent years due to the availability of large samples of intellectually precocious adolescents identified by modern talent searches that have been followed-up longitudinally over multiple decades. The level and pattern of cognitive abilities, even among participants within the top 1% of general intellectual ability, are related to differential developmental trajectories and important life accomplishments: The likelihood of earning a doctorate, earning exceptional compensation, publishing novels, securing patents, and earning tenure at a top university (and the academic disciplines within which tenure is most likely to occur) all vary as a function of individual differences in cognitive abilities assessed decades earlier. Individual differences that distinguish the able (top 1 in 100) from the exceptionally able (top 1 in 10,000) during early adolescence matter in life, and, given the heritability of general intelligence, they suggest that understanding the genetic and environmental origins of exceptional abilities should be a high priority for behavior genetic research, especially because the results for extreme groups could differ from the rest of the population. In addition to enhancing our understanding of the etiology of general intelligence at the extreme, such inquiry may also reveal fundamental determinants of specific abilities, like mathematical versus verbal reasoning, and the distinctive phenotypes that contrasting ability patterns are most likely to eventuate in at extraordinary levels.

Ability Differences Among People Who Have Commensurate Degrees Matter for Scientific Creativity

A sample of 1,586 intellectually talented adolescents (top 1%) were assessed on the math portion of the SAT by age 13 and tracked for more than 25 years. Patents and scientific publications were used as criteria for scientific and technological accomplishment. Participants were categorized according to whether their terminal degree was a bachelor's, master's, or doctorate degree, and within these degree groupings, the proportion of participants with at least one patent or scientific publication in adulthood increased as a function of this early SAT assessment. Information about individual differences in cognitive ability (even when measured in early adolescence) can predict differential creative potential in science and technology within populations that have advanced educational degrees.

IQ and the health of states

Epidemiologists contend that income inequality reduces the health and life expectancy of the whole population, but this argument does not make sense within its own evolutionary framework. Recent evolutionary psychological theory suggests that the human brain, adapted to the ancestral environment, has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment, and that general intelligence evolved as a domain-specific adaptation to solve evolutionarily novel problems. Since most dangers to health in the contemporary society are evolutionarily novel, it follows that more intelligent individuals are better able to recognize and deal with such dangers and live longer. Consistent with the theory, and replicating an earlier study of cross-national data, income inequality has no effect on the health and longevity of the population across the American states, when the racial composition (percent black) is controlled, but the average intelligence of the population (state IQ) has a significant effect. The data presented here and in the earlier study challenge the conclusion that income inequality reduces the health of the population.

SEXUAL SELECTION FOR MORAL VIRTUES

Moral evolution theories have emphasized kinship, reciprocity, group selection, and equilibrium selection. Yet, moral virtues are also sexually attractive. Darwin suggested that sexual attractiveness may explain many aspects of human morality. This paper updates his argument by integrating recent research on mate choice, person perception, individual differences, costly signaling, and virtue ethics. Many human virtues may have evolved in both sexes through mutual mate choice to advertise good genetic quality, parenting abilities, and/or partner traits. Such virtues may include kindness, fidelity, magnanimity, and heroism, as well as quasi-moral traits like conscientiousness, agreeableness, mental health, and intelligence. This theory leads to many testable predictions about the phenotypic features, genetic bases, and social-cognitive responses to human moral virtues.

Childhood cognitive performance and risk of mortality: a prospective cohort study of gifted individuals

Recent research suggests that childhood cognitive performance is associated with various health outcomes, but the nature of the relation is not well understood. It is unclear whether the association occurs across the continuum of cognitive performance, and if it is independent of socioeconomic status. Prospective data from the Terman Life Cycle Study were used to evaluate the hypothesis of a monotonic relation between childhood intelligence quotient (IQ) and adult mortality and to determine whether there exists a threshold beyond which the protective effects of IQ are no longer evident. A total of 897 individuals of school age who scored 135 or higher on the Stanford-Binet IQ test were recruited in 1922. Cox proportional hazards regression was used to estimate survival over a 64-year period. A 15-point advantage in childhood IQ was significantly associated with a decreased risk of mortality (hazard ratio = 0.68, 95% confidence interval: 0.49, 0.93) for IQ scores up to 163; beyond that, the risk of death plateaued. Results were similar when the sample was limited to those participants whose fathers had nonmanual occupations. Childhood IQ, even at the upper end of the distribution, is a significant predictor of mortality, independent of childhood social position.

Predictors of physical health: toward an integrated model of genetic and environmental antecedents

People in higher-income groups tend to experience better physical health, yet this does not appear to be the direct result of access to medical care. This has prompted a search for psychological factors more likely to be present in high-income environments that might help to explain the relationship. Physical health has been associated with a number of such psychological measures including positive affect and well-being, negative affect and neuroticism, positive social relationships, and perceived control. Building from recent findings of moderation of genetic variance in physical health by income and perceived control, we explore the genetic and environmental relationships among all these variables in a nationwide U.S. twin sample. These relationships suggest possible mechanisms by which psychological characteristics, behaviors, physical health, and environmental circumstances could be influenced by common groups of genes with varying degrees of activity in different environments. We discuss the implications of such mechanisms for differential expression of genetic variation in the population and suggest ways in which consideration of such effects can inform gerontology research.

Intelligence and maturity: meta-analytic evidence for the incremental and discriminant validity of Loevinger's measure of ego development

This review examined whether Loevinger's measure of personality (ego) development is equivalent to the measurement of intelligence. The authors conducted a meta-analysis of 52 correlations between ego level scores and intelligence test scores (retrieved from 42 studies involving 5,648 participants). The weighted average correlation between ego level and intelligence ranged from.20 to.34, depending on the intellectual ability assessed (e.g., verbal intelligence). Adjusting for measurement unreliability increased these values only minimally. The authors also reviewed 16 studies that examined the association between ego level and various criterion variables (e.g., aggressive behavior) after statistically controlling for the effects of intelligence. Ninety-four percent of the tests revealed significant relations between ego level and criterion variables after controlling for intelligence, indicating that ego development and intelligence are not interchangeable constructs. These findings do not support recent speculations concerning the limited value of stage models of maturity, social development, and moral reasoning.

Intelligence: is it the epidemiologists' elusive "fundamental cause" of social class inequalities in health?

Virtually all indicators of physical health and mental competence favor persons of higher socioeconomic status (SES). Conventional theories in the social sciences assume that the material disadvantages of lower SES are primarily responsible for these inequalities, either directly or by inducing psychosocial harm. These theories cannot explain, however, why the relation between SES and health outcomes (knowledge, behavior, morbidity, and mortality) is not only remarkably general across time, place, disease, and kind of health system but also so finely graded up the entire SES continuum. Epidemiologists have therefore posited, but not yet identified, a more general "fundamental cause" of health inequalities. This article concatenates various bodies of evidence to demonstrate that differences in general intelligence (g) may be that fundamental cause.

General mental ability in the world of work: occupational attainment and job performance

The psychological construct of general mental ability (GMA), introduced by C. Spearman (1904) nearly 100 years ago, has enjoyed a resurgence of interest and attention in recent decades. This article presents the research evidence that GMA predicts both occupational level attained and performance within one's chosen occupation and does so better than any other ability, trait, or disposition and better than job experience. The sizes of these relationships with GMA are also larger than most found in psychological research. Evidence is presented that weighted combinations of specific aptitudes tailored to individual jobs do not predict job performance better than GMA alone, disconfirming specific aptitude theory. A theory of job performance is described that explicates the central role of GMA in the world of work. These findings support Spearman's proposition that GMA is of critical importance in human affairs.

Introduction to the special section on cognitive abilities: 100 years after Spearman's (1904) "'General intelligence,' objectively determined and measured"

The study of individual differences in cognitive abilities is one of the few branches of psychological science to amass a coherent body of empirical knowledge withstanding the test of time. There is wide consensus that cognitive abilities are organized hierarchically, and C. Spearman's (1904) general intelligence occupies the vertex of this hierarchy. In addition, specific abilities beyond general intelligence refine longitudinal forecasts of important social phenomena and paint a rich portrait of this important domain of psychological diversity. This opening article identifies and then reviews 5 major areas concerning the personological significance of cognitive abilities and the methods used to study them. In models of human behavior and important life outcomes, cognitive abilities are critical in more ways than social scientists realize.

Academic performance, career potential, creativity, and job performance: can one construct predict them all?

This meta-analysis addresses the question of whether 1 general cognitive ability measure developed for predicting academic performance is valid for predicting performance in both educational and work domains. The validity of the Miller Analogies Test (MAT; W. S. Miller, 1960) for predicting 18 academic and work-related criteria was examined. MAT correlations with other cognitive tests (e.g., Raven's Matrices [J. C. Raven, 1965]; Graduate Record Examinations) also were meta-analyzed. The results indicate that the abilities measured by the MAT are shared with other cognitive ability instruments and that these abilities are generalizably valid predictors of academic and vocational criteria, as well as evaluations of career potential and creativity. These findings contradict the notion that intelligence at work is wholly different from intelligence at school, extending the voluminous literature that supports the broad importance of general cognitive ability (g).

Meeting the Educational Needs of Special Populations: Advanced Placement's Role in Developing Exceptional Human Capital

We evaluated the Advanced Placement (AP) program from the point of view of intellectually precocious youth and their subsequent educational-vocational outcomes, analyzing normative and idiographic longitudinal data collected across 30 years from 3,937 participants. Most took AP courses in high school, and those who did frequently nominated an AP course as their favorite. Students who took AP courses, compared with their intellectual peers who did not, appeared more satisfied with the intellectual caliber of their high school experience and, ultimately, achieved more. Overall, this special population placed a premium on intellectual challenge in high school and found the lack of such challenge distressing. These findings can inform contemporary educational policy debates regarding the AP program; they also have general implications for designing and evaluating educational interventions for students with special needs.

Intermittent lack of health insurance coverage and use of preventive services

OBJECTIVES

This study examined the association between intermittent lack of health insurance coverage and use of preventive health services.

METHODS

Analyses focused on longitudinal data on insurance status and preventive service use among a national sample of US adults who participated in the Health and Retirement Study.

RESULTS

Findings showed that, among individuals who obtain insurance coverage after histories of intermittent coverage, relatively long periods may be necessary to reestablish clinically appropriate care patterns. Increasing periods of noncoverage led to successively lower rates of use of most preventive services.

CONCLUSIONS

Intermittent lack of insurance coverage-even across a relatively long period-results in less use of preventive services. Studies that examine only current insurance status may underestimate the population at risk from being uninsured.

Scientific and social significance of assessing individual differences: "sinking shafts at a few critical points"

This chapter reviews empirical findings on the importance of assessing individual differences in human behavior. Traditional dimensions of human abilities, personality, and vocational interests play critical roles in structuring a variety of important behaviors and outcomes (e.g. achieved socioeconomic status, educational choices, work performance, delinquency, health risk behaviors, and income). In the review of their importance, the construct of general intelligence is featured, but attributes that routinely add incremental validity to cognitive assessments are also discussed. Recent experimental and methodological advances for better understanding how these dimensions may contribute to other psychological frameworks are reviewed, as are ways for determining their scientific significance within domains where they are not routinely assessed. Finally, some noteworthy models are outlined that highlight the importance of assessing relatively distinct classes of individual-differences attributes simultaneously. For understanding fully complex human phenomena such as crime, eminence, and educational-vocational development, such a multifaceted approach is likely to be the most productive.