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.     

Neuro-intelligence,neuro-metrics and the next phase of brain imaging studies

Twenty years have passed since the first neuro-imaging study of intelligence. Researchers from around the world are now using a variety of imaging techniques to investigate the neural basis of intelligence, establishing the field of “neuro-intelligence”. The papers in this special issue help usher in the next phase of neuro-intelligence research. Among other issues, they illustrate some of the progress made in identifying key brain areas and in elucidating the concept of brain efficiency. Samples include children, adults, and seniors. Imaging includes structural assessments and functional determinations during cognitive tests of memory and processing speed. Intelligence measures address g and other factors. Some brain/intelligence relationships apparently differ for males and females. The data are intriguing. The field is maturing. The pace is quickening. As intelligence research engages 21st century neuroscience, new hypotheses and new controversies are inevitable. What a terrific time to work in this field.     

Fluid intelligence is independently associated with all-cause mortality over 17 years in an elderly community sample: An investigation of potential mechanisms

The long-term relationship between lower intelligence and mortality risk in later life is well established, even when controlling for a range of health and sociodemographic measures. However, there is some evidence for differential effects in various domains of cognitive performance. Specifically, tests of fluid intelligence may have a stronger association with mortality than do tests of crystallized intelligence. The present study examines the relationship between intelligence and mortality in a sample of 896 Australian community-dwelling males and females, aged 70–97 at recruitment and followed for up to 17 years. There were 687 deaths during the follow-up period. Cox proportional hazard regression models examined whether the relationship between intelligence and mortality might be mediated by socioeconomic status, by health behaviors, by health status, or a combination of these. Higher fluid intelligence — as measured by the Symbol–Letter Modalities Test — was strongly associated with lower mortality rates (Hazard ratio = 0.80; 95% confidence interval = 0.72–0.88), even after accounting for any combination of potential mediators and confounders. A significant association between crystallized intelligence, as measured by the National Adult Reading Test, and mortality (HR = 0.89; 95% CI = 0.80–0.99) was attenuated by the inclusion of socioeconomic, health status measures, and health behavior measures and when deaths from the first four years of the study were excluded. The findings show little support for the hypothesized mechanisms of the intelligence–mortality relationship.     

The association between IQ in adolescence and a range of health outcomes at 40 in the 1979 US National Longitudinal Study of Youth

A link between pre-morbid intelligence and all cause mortality is becoming well established, but the aetiology of the association is not understood. Less is known about links with cause specific mortality and with morbidity. The aim of this study is to examine the association between intelligence measured in adolescence and a broad range of health outcomes ascertained at 40 years of age. We use data on 7476 participants in the US National Longitudinal Survey of Youth 1979 who had their cognitive ability measured at baseline and completed the ‘Health at 40’ interview module between 1998 and 2004. The Health at 40 module includes assessments of general health and depression, nine medically diagnosed conditions, and 33 common health problems. Higher mental test scores were associated with lower depression scores, better general health, significantly lower odds of having five of the nine diagnosed conditions and 15 of the 33 health problems. A health disadvantage of higher cognitive ability was evident for only three of the 33 health problems.     

Adolescent boys’ physical fighting and adult life outcomes: Examining the interplay with intelligence

Although it is well known that adolescent delinquent behavior is related to poor outcomes in adulthood, longitudinal research on specific acts of delinquency and their interplay with important individual characteristics in predicting future outcomes is scarce. We aimed to examine how physical fighting—one of the most common acts of violent delinquency among adolescent boys—is related to adult life success in several domains, and how intelligence influences these associations. The study used data from 1,083 boys that participated in the population-based longitudinal Young in Norway Study, following adolescents from 1992 to 2015, by combining self-reports at four time points with comprehensive information from registers. Results showed that adolescent boys’ physical fighting was associated with poor adult outcomes in the domains of employment, education, and criminal behavior. Associations remained significant even after controlling for conduct problems in general—which isolated the effects of fighting from other delinquent acts—as well as from a variety of other potential confounders. Detailed analyses on the interplay of physical fighting and intelligence showed that some parts of the associations between adolescent boys’ fighting and several adverse adult outcomes could be ascribed to lower intelligence among the fighters. Moreover, intelligence moderated the relationship between physical fighting and adult education. Adolescent fighting was not related to educational attainment among boys with high intelligence, whereas boys with lower intelligence experienced detrimental effects of adolescent fighting. The analyses show the importance of considering adolescent boys’ physical fighting as a potential risk factor for future social marginalization.     

The impact of childhood intelligence on later life: following up the Scottish mental surveys of 1932 and 1947

The Scottish Mental Surveys of 1932 and 1947 collected valid IQ-type test scores for almost everyone born in 1921 and 1936 and attending school on June 1, 1932 (N=89,498) and June 4, 1947 (N=70,805). These surveys are described. This research, using the surveys' data, examined (a) the stability of intelligence differences across the life span, (b) the determinants of cognitive change from childhood to old age, and (c) the impact of childhood intelligence on survival and health in old age. Surviving participants of the Scottish Mental Surveys were tested, and the surveys' data were linked with public and health records. Novel findings on the stability of IQ scores from age 11 to age 80; sex differences in cognitive aging; the dedifferentiation hypothesis of cognitive aging; and the effect of childhood IQ on all-cause and specific mortality, morbidity, and frailty in old age are presented.     

Personality and mortality risk across the life span: the importance of conscientiousness as a biopsychosocial attribute.

OBJECTIVE: This study addressed whether personality in childhood and personality in adulthood are independent predictors of mortality risk and the extent to which behavioral and other psychosocial factors can explain observed relationships between personality and mortality risk. DESIGN: This was a prospective longitudinal cohort study of 1,253 male and female Californians over 7 decades (1930-2000). Proportional hazards regressions were the principal analyses. MAIN OUTCOME MEASURES: Mortality risk (in the form of relative hazards) was the primary outcome. Additional tests of mediators and moderators ascertained whether associations between personality and mortality risk remained significant when psychosocial and behavioral variables were statistically controlled. RESULTS: The findings, including a new 14-year additional follow-up in old age, revealed that conscientiousness, measured independently in childhood and adulthood, predicted mortality risk across the full life span. The link from childhood remained robust when adult conscientiousness and certain behavioral variables were controlled. Psychosocial and behavioral variables partly explained the adult conscientiousness-longevity association. CONCLUSION: The findings demonstrate the utility and complexity of modern personality concepts in understanding health and point to conscientiousness as a key underexplored area for future biopsychosocial studies.     

Childhood intelligence predicts premature mortality: Results from a 40-year population-based longitudinal study

Childhood intelligence has been shown to predict mortality risk in adulthood. This relation has never been investigated in a Central European country with universal health care. The present study investigated whether childhood intelligence predicts mortality risk across 40 years in Luxembourg. 2543 participants completed an intelligence test at age 12 in 1968, and the mortality rate in this sample until 2008 was recorded. Our results showed that higher childhood intelligence predicted a lower risk for mortality, even when childhood socioeconomic status was controlled for. This effect was strongest in men belonging to the group of the lowest 20% in intelligence. These results indicate that even universal access to health care cannot fully offset the cumulative effects of intelligence on mortality.     

Examining the link between adolescent brain development and risk taking from a social–developmental perspective

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.     

Examining the link between adolescent brain development and risk taking from a social–developmental perspective (reprinted)

The adolescent age period is often characterized as a health paradox because it is a time of extensive increases in physical and mental capabilities, yet overall mortality/morbidity rates increase significantly from childhood to adolescence, often due to preventable causes such as risk taking. Asynchrony in developmental time courses between the affective/approach and cognitive control brain systems, as well as the ongoing maturation of neural connectivity are thought to lead to increased vulnerability for risk taking in adolescence. A critical analysis of the frequency of risk taking behaviors, as well as mortality and morbidity rates across the lifespan, however, challenges the hypothesis that the peak of risk taking occurs in middle adolescence when the asynchrony between the different developmental time courses of the affective/approach and cognitive control systems is the largest. In fact, the highest levels of risk taking behaviors, such as alcohol and drug use, often occur among emerging adults (e.g., university/college students), and highlight the role of the social context in predicting risk taking behavior. Moreover, risk taking is not always unregulated or impulsive. Future research should broaden the scope of risk taking to include risks that are relevant to older adults, such as risky financial investing, gambling, and marital infidelity. In addition, a lifespan perspective, with a focus on how associations between neural systems and behavior are moderated by context and trait-level characteristics, and which includes diverse samples (e.g., divorced individuals), will help to address some important limitations in the adolescent brain development and risk taking literature.     

The cognitive underpinnings of policy process studies: Introduction to a special issue of Cognitive Systems Research

This article introduces the special issue of Cognitive Systems Research on public policy processes. We begin with a discussion of the cognitive foundations of public policy that stem from the complexity of human cognition and emotion. Next, we provide an overview of the articles in the special issue, which occur at the edge of a public policy-cognitive systems boundary. We then turn to a discussion of promising new work in the study of public policy that explores—or may benefit from—the cognitive systems perspective.     

How intelligence and education contribute to substance use: Hints from the Minnesota Twin family study

In old and even middle age, there are associations between physical health and both intelligence and education. This may occur because intelligence and/or education exert effects on lifestyle choices that, in turn, affect later health. Substance use is one aspect of lifestyle choice in young adulthood that could play such a role. The effects of intelligence and/or education on substance use could be direct and environmental, or indirect due to the presence of confounding genetic and shared family influences. We used the Minnesota Twin Family Study to distinguish these effects in males and females at age 24. In contrast to prevailing expectations, there were moderately negative direct nonshared environmental effects of both IQ and education on both smoking and drinking in both males and females. That is, controlling for family background effects in the form of both genetic and shared environmental influences, both higher IQ and greater education were associated with greater alcohol and nicotine use. These effects were accounted for by alcohol and nicotine use at age 17. Our results suggest that genetic and family-culture variables confound the associations between intelligence and education and substance use in young adults, rendering them indirect. Further research is needed to understand the roles of IQ and education in alcohol and nicotine use and their relative impacts on physical health throughout the lifespan.     

Relational and psychological mediators of change in low‐income couples' perceived health

Experimental tests of the association between relationship functioning and physical health are limited. Although associations are hypothesized to be partially mediated through improved psychological functioning, tests are mostly limited to lab‐based studies. The present study evaluated relational and psychological mediators of change in perceived health in a sample of 742 low‐income couples (1,484 individuals) who participated in a randomized controlled trial of two online relationship education programs and a waitlist control group. Results partially supported the Strengths and Strains Model of Relationships and Physical Health. Relationship functioning and some psychological functioning were mediators of change in perceived health. Future research is needed to understand how relationship functioning improved perceived health through mediators other than psychological functioning tested here.     

Comparing comprehension and perception for alternative speed‐of‐ageing and standard hazard ratio formats

A hazard ratio presents one benefit of exercise as reducing annual mortality risk by 19%. Alternatively, speed‐of‐ageing metaphors present this as adding 2.5 years to one's life expectancy—equating to 1 extra hour each day—or taking 2.5 years off one's “effective age.” Few studies compare these (increasingly popular) metaphors. Study 1 compared perception and comprehension between speed‐of‐ageing metaphors and hazard ratios. Study 2 compared the hazard ratio with 3 versions of effective age (change‐in‐age, personal, and age‐matched age). Results revealed a disadvantage to the change‐in‐age format (behaviour X makes someone Y years older), with unhealthy behaviours perceived as less risky and healthy behaviours as less beneficial, information judged less likely to affect behaviour and harder to understand. The personal format (behaviour makes your effective age X) shows no such disadvantage and is objectively better understood than are hazard ratios. These results support the use of personalised effective ages in health and risk communication.     

A longitudinal investigation of perceived control and cognitive performance in young, midlife and older adults

Longitudinal associations between generalized control beliefs (one's perceived capacity to influence events) and cognitive test performance were examined in a population-based sample of young, midlife and older adults. Participants provided measures of perceived control, self-assessed health, education and depression and anxiety symptoms, and completed cognitive tests at two assessments, 4 years apart. For each age group, baseline (between-person) control was positively related to performance on tests of memory (immediate recall and digits backwards), speed (Symbol Digit Modalities Test and choice reaction time) and verbal intelligence (Spot-the-Word). Interaction effects indicated stronger associations of between-person control beliefs with indices of speed for the older age group relative to the younger groups. Within-person changes in control were not significantly associated with changes in cognitive test performance over the study interval. Implications of the findings for self-efficacy based interventions designed to promote cognitive functioning are discussed.     

How does education lead to healthier behaviours? Testing the mediational roles of perceived control,health literacy and social support

Abstract

Objectives: Educational attainment is increasingly recognised as a unique dimension of socioeconomic status (SES) and a powerful determinant of health behaviour—and thus physical health and mortality. However, very little is known about the specific pathways through which education influences these health behaviours. Design: The present study used a nationally representative US survey to test three potential psychosocial pathways (perceived control, health literacy and social support) through which education might influence intake of fruits and vegetables (FV), physical activity (PA) and sedentary behaviour (SB), controlling for other aspects of SES (income, health insurance status) and demographics (age, gender, race/ethnicity). Results: Both aspects of perceived control (locus of control, cancer fatalism) mediated the impact of education on FV and PA while only locus of control mediated the impact of education on SB. Further, only one aspect of health literacy (ability to understand recommendations) mediated education’s effect on any health behaviour (FV). Social support did not mediate any of the effects of education on health behaviors. Conclusion: Future work explicitly assessing and testing these mediational pathways is needed to better understand how education influences people’s health behaviours throughout their lives.     

Cognitive approaches to the study of episodic future thinking

The concept of episodic future thinking—the ability to simulate events that may take place in the personal future—has given rise to an exponentially growing field of research that spans a variety of sub-disciplines within psychology and neuroscience. In this introduction to the special issue, we provide a brief historical overview of factors that have shaped research on the topic and highlight the need for additional behavioural work to uncover cognitive mechanisms that support episodic future thinking and differentiate it from other related modes of future-oriented cognition. We conclude by discussing the manner in which the various contributions to the special issue fill the gaps in our knowledge and make some of our own suggestions for future work.     

Critical considerations about the use of poverty measures in the study of cognitive development

Developmental psychology and developmental cognitive neuroscience generated evidence at different levels of analysis about the influences of poverty on neurocognitive development (i.e., molecular, neural activation, cognition, behaviour). In addition, different individual and environmental factors were identified as mediators of such influences. Such a complexity is also illustrated through the many poverty conceptual and operational definitions generated by social, human and health sciences. However, to establish the causal relationships between the different factors of poverty and neurocognitive outcomes is still an issue under construction. Most studies of this area apply classic unidimensional poverty indicators such as income and maternal education. Nonetheless, this approach does not take into adequate consideration the variability of neurocognitive outcomes depending on the type of poverty measures, and the dynamic nature of changes during development. This creates a virtual underestimation of the complexity imposed by the involved mediating mechanisms. The scientific and policy implications of this underestimation include the risk of not adequately addressing children rights and developmental opportunities. This article proposes to explore such scenario, which is necessary for the reconsideration of the criteria used to analyse the influences of poverty on child development in general and neurocognitive development in particular.     

Personality and Serum Lipids: Does Lifestyle Account for Their Concurrent and Long‐term Relationships

This study evaluates concurrent and over time associations of personality with measures of three serum lipids associated coronary heart disease morbidity, namely, high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol and triglyceride (TRI). Participants were individuals who underwent a health examination at two points of time, T1 (N = 3835) and T2 (N = 2283), about 2.5 years apart. Personality was assessed by the Five‐Factor Model. Health, socioeconomic status and healthy lifestyle behaviours (smoking intensity, physical activity and body weight) were controlled. Regression analyses indicate that the personality factors of neuroticism, extraversion and conscientiousness are each significantly associated with HDL‐C and TRI, both concurrently and over time. However, most of these associations decreased to marginal significance when adjusted for body weight or physical activity as possible mediators. Both concurrent and over time associations of the openness personality trait with HDL‐C and TRI were significant and persisted after adjustment for measures of a healthy lifestyle. This study emphasizes the importance of collecting measures of a healthy lifestyle to better understand how personality might influence serum lipids. Copyright © 2013 European Association of Personality Psychology     

‘Bildung’ and Intercultural Understanding: A Dialogical Approach

In this introduction to the special issue on Bildung and dialogical self theory (DST), I explain why the notion of Bildung warrants elaboration in a special issue of the Journal of Constructivist Psychology. The concept of Bildung—for some, too apolitical and individualistic—gains significance by relating it to intercultural understanding as a prime challenge for plural societies in which cultural and religious diversity easily leads to confrontation and even violent conflict. The special issue offers an interdisciplinary discussion of the relevance of DST for this topic, of Bildung and humanism, and of the practice of intercultural adult education. In three articles, arguments for dialogical self as a prerequisite for intercultural adult education are placed within the broader context of pivotal discussions conducted within psychology, philosophy, and religious studies on the subject of our globalizing world.