Stay Sharp
The effect of retirement on cognitive functioning
Norma Coe et al.
Health Economics, forthcoming
Abstract:
Cognitive impairment has emerged as a major driver of disability in old age, with profound effects on individual well-being and decision making at older ages. In the light of policies aimed at postponing retirement ages, an important question is whether continued labour supply helps to maintain high levels of cognition at older ages. We use data of older men from the US Health and Retirement Study to estimate the effect of continued labour market participation at older ages on later-life cognition. As retirement itself is likely to depend on cognitive functioning and may thus be endogenous, we use offers of early retirement windows as instruments for retirement in econometric models for later-life cognitive functioning. These offers of early retirement are legally required to be nondiscriminatory and thus, inter alia, unrelated to cognitive functioning. At the same time, these offers of early retirement options are significant predictors of retirement. Although the simple ordinary least squares estimates show a negative relationship between retirement duration and various measures of cognitive functioning, instrumental variable estimates suggest that these associations may not be causal effects. Specifically, we find no clear relationship between retirement duration and later-life cognition for white-collar workers and, if anything, a positive relationship for blue-collar workers.
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Jorge Varela et al.
Law and Human Behavior, December 2011, Pages 501-511
Abstract:
Criminal defense attorneys (N = 142) responded to a survey asking them to read a vignette describing a Hispanic defendant charged with assault and rate the severity of the defendant's mental illness and likelihood of referring him for an evaluation of competence to stand trial (CST). The vignettes varied in terms of whether the defendant spoke English or Spanish, and whether his mental illness symptoms were obvious or ambiguous. Overall, attorneys rated the Spanish-speaking defendant as less mentally ill than the English-speaking defendant, and were less likely to refer the Spanish-speaking defendant for a CST evaluation. Attorneys who perceived more logistical barriers to seeking a CST evaluation in their local communities were less likely to refer the defendant for a CST evaluation, but only when the defendant spoke Spanish. These findings suggest attorney decisions were influenced by language, although further research is needed to identify the mechanism of this influence.
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Intellectual ability in young men separated temporarily from their parents in childhood
Anu-Katriina Pesonen et al.
Intelligence, September-October 2011, Pages 335-341
Abstract:
We examined the effects of early life stress (ELS) on intellectual ability in 2,725 20-year-old male participants, of whom 321 were separated temporarily (mean 1.7 years) from both their parents during World War II, at an average age of 4.3 years. Intellectual ability was tested when entering compulsory military service. The separated men had - 0.28 (95% CI - 0.39, - 0.16), - 0.13 (95% CI - 0.25, - 0.01), - 0.18 (95% CI - 0.29, - 0.06), and - 0.19 (95% CI - 0.30, - 0.07) SD units lower verbal, visuospatial, arithmetic, and composite score of intellectual ability, respectively, compared to non-separated. Participants who were separated for more than a year and between two and four years had the lowest ability scores. ELS showed most consistent associations with verbal ability, but were not limited to it. Children beyond infancy and before their school-age may be the most vulnerable to the adverse effects of the ELS.
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Predicting Lawyer Effectiveness: Broadening the Basis for Law School Admission Decisions
Marjorie Shultz & Sheldon Zedeck
Law & Social Inquiry, Summer 2011, Pages 620-661
Abstract:
Law school admission decisions are heavily influenced by a student's undergraduate grade point average (UGPA) and Law School Admission Test (LSAT) score. These measures, although predictive of first-year law school grades, make no effort to predict professional competence and, for the most part, they do not. These measures also create adverse impact on applicants from underrepresented racial/ethnic groups. This article describes the rationale for and process by which we explored new tests to predict lawyer effectiveness rather than law school grades and reports results of a multiyear empirical study involving over 3,000 graduates from Berkeley Law School and Hastings College of the Law. Tests measuring personality constructs, interests, values, and judgment predicted lawyering competency but had little or no adverse impact on underrepresented minority applicants. Combined with the LSAT and UGPA, these broader tests could assess law applicants on the basis both of projected professional effectiveness and academic indicators.
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Kevin Rand, Allison Martin & Amanda Shea
Journal of Research in Personality, forthcoming
Abstract:
This longitudinal study examined the relative associations of initial levels of hope and optimism with subsequent academic performance and life satisfaction among first-year law students (N = 86). Path analysis showed that hope, but not optimism, predicted better academic performance, while controlling for Law School Admission Test scores and undergraduate grades. Both hope and optimism uniquely predicted greater life satisfaction at the end of the first semester.
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Positive fantasies predict low academic achievement in disadvantaged students
Heather Barry Kappes, Gabriele Oettingen & Doris Mayer
European Journal of Social Psychology, forthcoming
Abstract:
Unlike other forms of positive thinking (e.g., expectations), research finds that positive fantasies (experiencing one's thoughts and mental images about the future positively) predict low effort and little success in several domains. However, for vocational education students of low socioeconomic status and minority ethnicity, for whom the present environment is especially difficult, perhaps it would be appropriate to indulge in positive fantasies that depict the future as bright and easily attained. Three studies show that this is not the case. Positive future fantasies measured early in the program predicted more days absent (Studies 2-3) and lower grades at the end of the program (Studies 1-3), even when adjusting for initial academic competence, expectations of successful achievement, and self-discipline. Expectations of successful achievement predicted fewer days absent and higher grades only when measured midway through the school year, once participants had experience with their own academic standing (Study 3). Results indicate that positive fantasies, which allow people to indulge in images of a bright future, predict poor achievement even in vocational students immersed in a particularly difficult environment.
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A comparison of temperament in nonhuman apes and human infants
Esther Herrmann et al.
Developmental Science, forthcoming
Abstract:
The adaptive behavior of primates, including humans, is often mediated by temperament. Human behavior likely differs from that of other primates in part due to temperament. In the current study we compared the reaction of bonobos, chimpanzees, orangutans, and 2.5-year-old human infants to novel objects and people - as a measure of their shyness-boldness, a key temperamental trait. Human children at the age of 2.5 years avoided novelty of all kinds far more than the other ape species. This response was most similar to that seen in bonobos and least like that of chimpanzees and orangutans. This comparison represents a first step in characterizing the temperamental profiles of species in the hominoid clade, and these findings are consistent with the hypothesis that human temperament has evolved since our lineage diverged from the other apes in ways that likely have broad effects on behavior. These findings also provide new insights into how species differences in ecology may shape differences in temperament.
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Janice Kiecolt-Glaser et al.
Brain, Behavior, and Immunity, forthcoming
Abstract:
Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) productions and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis.
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Genome-wide association studies establish that human intelligence is highly heritable and polygenic
G. Davies et al.
Molecular Psychiatry, forthcoming
Abstract:
General intelligence is an important human quantitative trait that accounts for much of the variation in diverse cognitive abilities. Individual differences in intelligence are strongly associated with many important life outcomes, including educational and occupational attainments, income, health and lifespan. Data from twin and family studies are consistent with a high heritability of intelligence, but this inference has been controversial. We conducted a genome-wide analysis of 3511 unrelated adults with data on 549 692 single nucleotide polymorphisms (SNPs) and detailed phenotypes on cognitive traits. We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants. These estimates provide lower bounds for the narrow-sense heritability of the traits. We partitioned genetic variation on individual chromosomes and found that, on average, longer chromosomes explain more variation. Finally, using just SNP data we predicted ~1% of the variance of crystallized and fluid cognitive phenotypes in an independent sample (P=0.009 and 0.028, respectively). Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence.
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Annie Ginty et al.
International Journal of Psychophysiology, forthcoming
Abstract:
The relationship between cardiovascular reactions to acute mental challenge in the laboratory and cognitive ability has received scant attention. The present study examined the association between reactivity and future cognitive ability. Heart rate and blood pressure reactions to a mental stress task were measured in 1647 participants comprising three distinct age cohorts. Cognitive ability was assessed using the Alice Heim-4 test of general intelligence and choice reaction time 5 and 12 years later. High heart rate reactivity was related to higher general intelligence scores and faster choice reaction times at both follow-ups. High heart rate reactivity was also associated with a smaller decline in cognitive ability between assessments. These associations were still evident following adjustment for a wide range of potentially confounding variables. The present results are consistent with the notion that high reactivity may not always be a maladaptive response and that low or blunted reactivity may also have negative corollaries.
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Katherine Karlsgodt et al.
Behavioural Brain Research, forthcoming
Abstract:
Working memory is a highly heritable complex cognitive trait that is critical for a number of higher-level functions. However, the neural substrates of this behavioral phenotype are intricate and it is unknown through what precise biological mechanism variation in working memory is transmitted. In this review we explore different functional and structural components of the working memory circuitry, and the degree to which each of them is contributed to by genetic factors. Specifically, we consider dopaminergic function, glutamatergic function, white matter integrity and grey matter structure all of which provide potential mechanisms for the inheritance of working memory deficits. In addition to discussing the overall heritability of these measures we also address specific genes that may play a role. Each of these heritable components has the potential to uniquely contribute to the working memory deficits observed in genetic disorders, including 22q deletion syndrome, fragile X syndrome, phenylketonuria (PKU), and schizophrenia. By observing the individual contributions of disruptions in different components of the working memory circuitry to behavioral performance, we highlight the concept that there may be many routes to a working memory deficit; even though the same cognitive measure may be a valid endophenotype across different disorders, the underlying cause of, and treatment for, the deficit may differ. This has implications for our understanding of the transmission of working memory deficits in both healthy and disordered populations.
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Kristin Sheffield & Kristen Peek
American Journal of Epidemiology, 1 August 2011, Pages 274-283
Abstract:
The authors used data from 6 waves of the Health and Retirement Study to evaluate changes in the prevalence of cognitive impairment among adults 70 years of age or older from 1993 to 2004. Having sampling weights for each wave enabled the authors to create merged waves that represented cross-sections of the community-dwelling older population for that year. Logistic regression analyses with year as the predictor were used to estimate trends and determine the contribution of sociodemographic and health status variables to decreasing trends in the prevalence of cognitive impairment over time (score ≤8 on a modified Telephone Interview Cognitive Screen). Results showed an annual decline in the prevalence of cognitive impairment of 3.4% after adjustment for age, gender, and prior test exposure (odds ratio (OR) = 0.966, 95% confidence interval (CI): 0.941, 0.992). The addition of socioeconomic variables to the model attenuated the trend by 72.1%. The annual percentage of decline in impairment was larger for blacks (OR = 0.943, 95% CI: 0.914, 0.973) and Hispanics (OR = 0.954, 95% CI: 0.912, 0.997) than for whites (OR = 0.971, 95% CI: 0.936, 1.006), although the differences were not statistically significant. Linear probability models used in secondary analyses showed larger percentage-point declines for blacks and Hispanics. Improvements in educational level contributed to declines in cognitive impairment among older adults-particularly blacks and Hispanics-in the United States.
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Sujin Yang, Hwajin Yang & Barbara Lust
Bilingualism, July 2011, Pages 412-422
Abstract:
This study investigated whether early especially efficient utilization of executive functioning in young bilinguals would transcend potential cultural benefits. To dissociate potential cultural effects from bilingualism, four-year-old U.S. Korean-English bilingual children were compared to three monolingual groups - English and Korean monolinguals in the U.S.A. and another Korean monolingual group, in Korea. Overall, bilinguals were most accurate and fastest among all groups. The bilingual advantage was stronger than that of culture in the speed of attention processing, inverse processing efficiency independent of possible speed-accuracy trade-offs, and the network of executive control for conflict resolution. A culture advantage favoring Korean monolinguals from Korea was found in accuracy but at the cost of longer response times.
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Predicting the performance and innovativeness of scientists and engineers
Robert Keller
Journal of Applied Psychology, forthcoming
Abstract:
A study of 644 scientists and engineers from 5 corporate research and development organizations investigated hypotheses generated from an interactionist framework of 4 individual characteristics as longitudinal predictors of performance and innovativeness. An innovative orientation predicted 1-year-later and 5-years-later supervisory job performance ratings and 5-years-later counts of patents and publications. An internal locus of control predicted 5-years-later patents and publications, and self-esteem predicted performance ratings for both times and patents. Team-level nonroutine tasks moderated the individual-level relationships between an innovative orientation and performance ratings and patents such that the relationships were stronger in a nonroutine task environment. Implications for an interactionist framework of performance and innovativeness for knowledge workers are discussed.
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Makeba Parramore Wilbourn, Allen Gottfried & Daniel Kee
Developmental Psychology, July 2011, Pages 931-942
Abstract:
The relationship between consistency of hand preference, left hemispheric specialization, and cognitive functioning was examined in an ongoing longitudinal investigation. Children were classified as consistent or inconsistent in their hand preference across 5 assessments from ages 18 to 42 months. Findings demonstrated that (a) this early classification continued to reveal differences in cognitive functioning from 10 to 17 years but only for girls, (b) consistent girls' performances were continually higher relative to the inconsistent girls on measures of verbal intelligence and reading achievement, (c) differences between the female groups were specifically related to left-hemispheric language specialization, and (d) one factor influencing the consistent girls' development may be the amount of reading exposure received during infancy.