Intellectual interest mediates gene × socioeconomic status interaction on adolescent academic achievement

The influence of family socio-economic status on learning engagement of college students majoring in preschool education: The mediating role of parental autonomy support and the moderating effect of psychological capital

Objective

To explore the relationship between family socio-economic status and learning engagement of college students majoring in preschool education, as well as the mediating role of parental autonomy support and the moderating role of psychological capital.

Methods

A sample of 986 college students majoring in preschool education from Guangdong Province and Jiangxi Province were investigated by family socio-economic status questionnaire, learning engagement questionnaire, parental autonomy support questionnaire and psychological capital questionnaire.

Results

First, there was a significant positive correlation between family socio-economic status and learning engagement (β = 0.09, p < 0.05). Second, parental autonomy support played a completely mediating role between family socio-economic status and learning engagement (β = 0.05, p < 0.01). Third, the relationship between parental autonomy support and learning engagement was moderated by psychological capital, and students with high psychological capital had higher learning engagement (β = 0.24, p < 0.001).

Conclusion

Family socio-economic status could directly affect learning engagement, and could also indirectly affect learning engagement through psychological capital level moderating parental autonomy support. Our findings highlight the importance of creating an autonomous supportive family environment and focusing on the learning of students from low socio-economic status. Meanwhile, stimulating students' psychological capital should be regarded as a part of education and teaching.

Transcend socioeconomic status constraints to mathematics and science achievement by collaborative problem-solving: The female people-smartness hypothesis

This study examines the female people-smartness (FPS) hypothesis, which addresses the reasons why females are more responsive to socioeconomic status (SES) and posits that using females’ strengths of people-smartness can assist females to overcome SES constraints. This study used data from the student surveys of the Program for International Student Assessment (PISA) in 2015, including 519,334 students from 72 participating countries and economies. The results of the general linear model analysis revealed that females are better at collaborative problem-solving (CPS) and reading, while males are better at mathematics and science. Structural equation modeling revealed that the effect of SES on (mathematics and science) achievement is higher for females than for males. CPS can reduce the effect of SES on achievement. The findings generally support the FPS hypothesis and suggest that CPS-related competences should be emphasized and exercised to transcend SES constraints, especially for females in STEM curricula, studies and careers.

Investigating the genetic architecture of noncognitive skills using GWAS-by-subtraction

Little is known about the genetic architecture of traits affecting educational attainment other than cognitive ability. We used genomic structural equation modeling and prior genome-wide association studies (GWASs) of educational attainment (n = 1,131,881) and cognitive test performance (n = 257,841) to estimate SNP associations with educational attainment variation that is independent of cognitive ability. We identified 157 genome-wide-significant loci and a polygenic architecture accounting for 57% of genetic variance in educational attainment. Noncognitive genetics were enriched in the same brain tissues and cell types as cognitive performance, but showed different associations with gray-matter brain volumes. Noncognitive genetics were further distinguished by associations with personality traits, less risky behavior and increased risk for certain psychiatric disorders. For socioeconomic success and longevity, noncognitive and cognitive-performance genetics demonstrated associations of similar magnitude. By conducting a GWAS of a phenotype that was not directly measured, we offer a view of genetic architecture of noncognitive skills influencing educational success.

Cognitive ability and education: How behavioural genetic research has advanced our knowledge and understanding of their association

Cognitive ability and educational success predict positive outcomes across the lifespan, from higher earnings to better health and longevity. The shared positive outcomes associated with cognitive ability and education are emblematic of the strong interconnections between them. Part of the observed associations between cognitive ability and education, as well as their links with wealth, morbidity and mortality, are rooted in genetic variation. The current review evaluates the contribution of decades of behavioural genetic research to our knowledge and understanding of the biological and environmental basis of the association between cognitive ability and education. The evidence reviewed points to a strong genetic basis in their association, observed from middle childhood to old age, which is amplified by environmental experiences. In addition, the strong stability and heritability of educational success are not driven entirely by cognitive ability. This highlights the contribution of other educationally relevant noncognitive characteristics. Considering both cognitive and noncognitive skills as well as their biological and environmental underpinnings will be fundamental in moving towards a comprehensive, evidence-based model of education.

Kids becoming less alike: A behavioral genetic analysis of developmental increases in personality variance from childhood to adolescence

Recent work in personality development has indicated that the magnitude of individual differences in personality increases over child development. Do such patterns reflect the differentiation of individuals by genotype, an increasing influence of environmental factors, or some (interactive) combination of the two? Using a population-based sample of over 2,500 twins and multiples from the Texas Twin Project, we estimated age trends in the variances in self- and parent-reported measures of the Big Five personality traits between Ages 8 and 18 years. We then estimated age trends in the genetic and environmental components of variance in each measure. Individual differences in personality increased in magnitude from childhood through mid-adolescence. This pattern emerged using both children's self-reports and ratings provided by their parents, and was primarily attributable to increases in the magnitude of genetic influences. Most of the increasing genetic variance appeared nonadditive, pointing to the possibility that developmental processes tend to make genetically similar individuals disproportionately more alike in their personality traits over time. These findings could reflect increasing or accumulating effects of trait-by-trait interactions; person-by-environment transactions, whereby genetically similar people are disproportionally likely to experience similar environments; the activation of dominant genes across developmental transitions (e.g., puberty); or some combination of these three processes, among other factors. Theories of personality development will need to accommodate these descriptive findings, and longitudinal, genetically informed designs are needed to test some of the specific hypotheses springing from this study. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Intellectual Performance and Educational Attainment of Mexican Adolescents in Poverty

The objective of this study was to determine factors that can predict the intellectual performance and educational attainment of adolescents living in poverty. Data of Mexican adolescents from rural and urban areas (N = 1,093, 55.8% male, 61% urban) and their mothers were analyzed. The data came from a probabilistic sample with national representativeness of beneficiary households of the governmental program to fight poverty Oportunidades. Mothers and children were surveyed separately at home using questionnaires. Results from structural equations modeling revealed that higher intellectual performance was determined by older age, higher maternal intellectual performance and education, more adequate parenting practices, fewer siblings, and less insecure neighborhoods. Higher educational attainment was predicted by older age, higher intellectual performance, and more psychological resources. Data explained 25% of the variance of intellectual performance, and 39% of the variance of educational attainment. Results are discussed regarding the possibility of enhancing intellectual performance and education.

National Gross Domestic Product, Science Interest, and Science Achievement: A Direct Replication and Extension of the Tucker-Drob, Cheung, and Briley (2014) Study

We replicated the study by Tucker-Drob, Cheung, and Briley (2014), who found that the association between science interest and science knowledge depended on economic resources at the family, school, and national levels, using data from the 2006 Programme for International Student Assessment (PISA). In more economically prosperous families, schools, and nations, student interest was more strongly correlated with actual knowledge. Here, we investigated whether these results still held despite substantial changes to educational and economic systems over roughly a decade. Using similar data from PISA 2015 ( N = 537,170), we found largely consistent results. Students from more economically advantaged homes, schools, and nations exhibited a stronger link between interests and knowledge. However, these moderation effects were substantially reduced, and the main effect of science interest increased by nearly 25%, driven almost entirely by families of low socioeconomic status and nations with low gross domestic product. The interdependence of interests and resources is robust but perhaps weakening with educational progress.

Microbes and the Mind: How Bacteria Shape Affect, Neurological Processes, Cognition, Social Relationships, Development, and Pathology

Recent data suggest that the human body is not so exclusively human after all. Specifically, humans share their bodies with approximately 10 trillion microorganisms, collectively known as the microbiome. Chief among these microbes are bacteria, and there is a growing consensus that they are critical to virtually all facets of normative functioning. This article reviews the ways in which bacteria shape affect, neurological processes, cognition, social relationships, development, and psychological pathology. To date, the vast majority of research on interactions between microbes and humans has been conducted by scientists outside the field of psychology, despite the fact that psychological scientists are experts in many of the topics being explored. This review aims to orient psychological scientists to the most relevant research and perspectives regarding the microbiome so that we might contribute to the now widespread, interdisciplinary effort to understand the relationship between microbes and the mind.

"Same but different": Associations between multiple aspects of self-regulation, cognition, and academic abilities

Self-regulation describes the ability to control both behaviors and internal states against a backdrop of conflicting or distracting situations, drives, or impulses. In the cognitive psychology tradition, individual differences in self-regulation are commonly measured with performance-based tests of executive functioning, whereas in the personality psychology tradition, individual differences in self-regulation are typically assessed with report-based measures of impulse control, sustained motivation, and perseverance. The goal of this project was (a) to comprehensively examine the structure of associations between multiple self-regulatory constructs stemming from the cognitive and personality psychology traditions; (b) to estimate how these constructs, individually and collectively, related to mathematics and reading ability beyond psychometric measures of processing speed and fluid intelligence; and (c) to estimate the extent to which genetic and environmental factors mediated the observed associations. Data were available for 1,019 child participants from the Texas Twin Project (M age = 10.79, range = 7.8-15.5). Results highlighted the differentiation among cognitive and personality aspects of self-regulation, both at observed and genetic levels. After accounting for processing speed and fluid intelligence, EF remained a significant predictor of reading and mathematics ability. Educationally relevant measures of personality-particularly an openness factor representing curiosity and intellectual self-concept-incrementally contributed to individual differences in reading ability. Collectively, measures of cognition, self-regulation, and other educationally relevant aspects of personality accounted for the entirety of genetic variance in mathematics and reading ability. The current findings point to the important independent role that each construct plays in academic settings. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neurobehavioral correlates of obesity are largely heritable

Obesity is a widespread heritable health condition. Evidence from psychology, cognitive neuroscience, and genetics has proposed links between obesity and the brain. The current study tested whether the heritable variance in body mass index (BMI) is explained by brain and behavioral factors in a large brain imaging cohort that included multiple related individuals. We found that the heritable variance in BMI had genetic correlations 0.25–0.45 with cognitive tests, cortical thickness, and regional brain volume. In particular, BMI was associated with frontal lobe asymmetry and differences in temporal-parietal perceptual systems. Further, we found genetic overlap between certain brain and behavioral factors. In summary, the genetic vulnerability to BMI is expressed in the brain. This may inform intervention strategies.

Recent molecular genetic studies have shown that the majority of genes associated with obesity are expressed in the central nervous system. Obesity has also been associated with neurobehavioral factors such as brain morphology, cognitive performance, and personality. Here, we tested whether these neurobehavioral factors were associated with the heritable variance in obesity measured by body mass index (BMI) in the Human Connectome Project (n = 895 siblings). Phenotypically, cortical thickness findings supported the “right brain hypothesis” for obesity. Namely, increased BMI is associated with decreased cortical thickness in right frontal lobe and increased thickness in the left frontal lobe, notably in lateral prefrontal cortex. In addition, lower thickness and volume in entorhinal-parahippocampal structures and increased thickness in parietal-occipital structures in participants with higher BMI supported the role of visuospatial function in obesity. Brain morphometry results were supported by cognitive tests, which outlined a negative association between BMI and visuospatial function, verbal episodic memory, impulsivity, and cognitive flexibility. Personality–BMI correlations were inconsistent. We then aggregated the effects for each neurobehavioral factor for a behavioral genetics analysis and estimated each factor’s genetic overlap with BMI. Cognitive test scores and brain morphometry had 0.25–0.45 genetic correlations with BMI, and the phenotypic correlations with BMI were 77–89% explained by genetic factors. Neurobehavioral factors also had some genetic overlap with each other. In summary, obesity as measured by BMI has considerable genetic overlap with brain and cognitive measures. This supports the theory that obesity is inherited via brain function and may inform intervention strategies.

Does the heritability of cognitive abilities vary as a function of parental education? Evidence from a German twin sample

A well-known hypothesis in the behavioral genetic literature predicts that the heritability of cognitive abilities is higher in the presence of higher socioeconomic contexts. However, studies suggest that the effect of socioeconomic status (SES) on the heritability of cognitive ability may not be universal, as it has mostly been demonstrated in the United States, but not in other Western nations. In the present study we tested whether the importance of genetic and environmental effects on cognitive abilities varies as a function of parental education in a German twin sample. Cognitive ability scores (general, verbal, and nonverbal) were obtained on 531 German twin pairs (192 monozygotic, 339 dizygotic, ranging from 7 to 14 years of age; M_age = 10.25, SD = 1.83). Data on parental education were available from mothers and fathers. Results for general cognitive ability and nonverbal ability indicated no significant gene x parental education interaction effect. For verbal ability, a significant nonshared environment (E) x parental education interaction was found in the direction of greater nonshared environmental influences on verbal abilities among children raised by more educated parents.

Mediators of the Effect of Childhood Socioeconomic Status on Late Midlife Cognitive Abilities: A Four Decade Longitudinal Study

Background and Objectives

Childhood socioeconomic status (cSES) is found to predict later-life cognitive abilities, yet the mechanisms underlying these associations remain unclear. The objective of this longitudinal study was to examine the direct and indirect paths through which cSES influences late midlife cognitive outcomes.

Research Design and Methods

Participants were 1,009 male twins in the Vietnam Era Twin Study of Aging (VETSA). At mean ages 20 and 62, participants completed a standardized test for general cognitive ability (GCA). The age 62 cognitive assessment also included in-person tests of processing speed, episodic memory, abstract reasoning, working memory, verbal fluency, visual-spatial ability, and executive functions. At mean age 56, participants were interviewed regarding their own and their parents’ education and occupation, and completed questionnaires about cognitive leisure activities and sociodemographic information. Multiple mediation analyses were conducted to examine the direct path effects and indirect path effects of cSES through age 20 GCA, adult SES, and cognitive leisure activities on seven cognitive outcomes at age 62, adjusting for age, ethnicity, and non-independence of observations.

Results

Total (direct plus indirect) effects were significant for all measures with the exception of executive functions. Men from lower cSES backgrounds had poorer cognitive functioning in late midlife. The direct effect of cSES was partially mediated for abstract reasoning, and was fully mediated for the remaining six cognitive outcomes. Total indirect effects accounted for at least half of the total effects in each model, with paths through age 20 GCA explaining most of the total indirect effects.

Discussion and Implications

cSES predicted cognitive functioning in late middle age Using multiple mediation models, we show that lower cSES predicts poorer cognition in late midlife primarily through young adult cognitive ability and to a lesser extent through SES in adulthood and engagement in cognitively stimulating activities.

Reading self-perceived ability, enjoyment and achievement: A genetically informative study of their reciprocal links over time

Extant literature has established a consistent association between aspects of reading motivation, such as enjoyment and self-perceived ability, and reading achievement, in that more motivated readers are generally more skilled readers. However, the developmental etiology of this relation is yet to be investigated. The present study explores the development of the motivation-achievement association and its genetic and environmental underpinnings. Applying cross-lagged design in a sample of 13,825 twins, we examined the relative contribution of genetic and environmental factors to the association between reading enjoyment and self-perceived ability and reading achievement. Children completed a reading comprehension task and self-reported their reading enjoyment and perceived ability twice in middle childhood: when they were 9-10 and 12 years old. Results showed a modest reciprocal association over time between reading motivation (enjoyment and perceived ability) and reading achievement. Reading motivation at age 9-10 statistically predicted the development of later achievement, and similarly, reading achievement at age 9-10 predicted the development of later motivation. This reciprocal association was observed beyond the stability of the variables and their contemporaneous correlation and was largely explained by genetic factors. (PsycINFO Database Record

Little Evidence That Socioeconomic Status Modifies Heritability of Literacy and Numeracy in Australia

Socioeconomic status (SES) has been found to moderate the influence of genes and the environment on cognitive ability, such that genetic influence is greater when SES is higher, and the shared environment is greater when SES is lower, but not in all Western countries. The effects of both family and school SES on the heritability of literacy and numeracy in Australian twins aged 8, 10, 12, and 14 years with 1,307, 1,235, 1,076, and 930 pairs at each age, respectively, were tested. Shared environmental influences on Grade 3 literacy were greater with low family SES, and no other moderating effects of SES were significant. These findings are contrasted with results from the United States and the United Kingdom.

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.

Genetically-mediated associations between measures of childhood character and academic achievement

Researchers and the general public have become increasingly intrigued by the roles that systematic tendencies toward thinking, feeling, and behaving might play in academic achievement. Some measures of constructs belonging to this group have been well studied in genetics and psychometrics, while much less is known about measures of other such constructs. The current study focuses on 7 character traits prominently featured in influential intervention-oriented and/or socialization theories of academic achievement: grit, intellectual curiosity, intellectual self-concept, mastery orientation, educational value, intelligence mindset, and test motivation. In a population-based sample of 811 school-aged twins and triplets from the Texas Twin Project, we tested (a) how each measure relates to indices of the Big Five personality traits, (b) how the measures relate to one another, (c) the extent to which each measure is associated with genetic and environmental influences and whether such influences operate through common dimensions of individual differences, and (d) the extent to which genetic and environmental factors mediate the relations between fluid intelligence, character measures, verbal knowledge, and academic achievement. We find moderate relations among the measures that can be captured by a highly heritable common dimension representing a mixture of Openness and Conscientiousness. Moreover, genetically influenced variance in the character measures is associated with multiple measures of verbal knowledge and academic achievement, even after controlling for fluid intelligence. In contrast, environmentally influenced variance in character is largely unrelated to knowledge and achievement outcomes. We propose that character measures popularly used in education may be best conceptualized as indexing facets of personality that are of particular relevance to academic achievement. (PsycINFO Database Record

Sensation seeking, peer deviance, and genetic influences on adolescent delinquency: Evidence for person-environment correlation and interaction

Both sensation seeking and affiliation with deviant peer groups are risk factors for delinquency in adolescence. In this study, we use a sample of adolescent twins (n = 549), 13 to 20 years old (M age = 15.8 years), in order to test the interactive effects of peer deviance and sensation seeking on delinquency in a genetically informative design. Consistent with a socialization effect, affiliation with deviant peers was associated with higher delinquency even after controlling for selection effects using a co-twin-control comparison. At the same time, there was evidence for person-environment correlation; adolescents with genetic dispositions toward higher sensation seeking were more likely to report having deviant peer groups. Genetic influences on sensation seeking substantially overlapped with genetic influences on adolescent delinquency. Finally, the environmentally mediated effect of peer deviance on adolescent delinquency was moderated by individual differences in sensation seeking. Adolescents reporting high levels of sensation seeking were more susceptible to deviant peers, a Person × Environment interaction. These results are consistent with both selection and socialization processes in adolescent peer relationships, and they highlight the role of sensation seeking as an intermediary phenotype for genetic risk for delinquency. (PsycINFO Database Record

Parenting Supports for Early Vocabulary Development: Specific Effects of Sensitivity and Stimulation through Infancy

Growing recognition of disparities in early childhood language environments prompt examination of parent-child interactions which support vocabulary. Research links parental sensitivity and cognitive stimulation to child language, but has not explicitly contrasted their effects, nor examined how effects may change over time. We examined maternal sensitivity and stimulation throughout infancy using two observational methods - ratings of parents' interaction qualities, and coding of discrete parenting behaviors - to assess the relative importance of these qualities to child vocabulary over time, and determine whether mothers make related changes in response to children's development. Participants were 146 infants and mothers, assessed when infants were 14, 24, and 36 months. At 14 months, sensitivity had a stronger effect on vocabulary than did stimulation, but the effect of stimulation grew throughout toddlerhood. Mothers' cognitive stimulation grew over time, whereas sensitivity remained stable. While discrete parenting behaviors changed with child age, there was no evidence of trade-offs between sensitive and stimulating behaviors, and no evidence that sensitivity moderated the effect of stimulation on child vocabulary. Findings demonstrate specificity of timing in the link between parenting qualities and child vocabulary which could inform early parent interventions, and supports a reconceptualization of the nature and measurement of parental sensitivity.

Success in School for Justice-Involved Girls: Do Specific Aspects of Developmental Immaturity Matter?

Developmental immaturity (DI) may help explain some of the variability in aspects of academic achievement among girls in the juvenile justice system, a population with high rates of truancy, dropout, and school failure. This study examined the relationships among the decision making and independent functioning components of DI, verbal intelligence, and academic achievement within this population. Using data from 60 girls in residential juvenile justice facilities, multiple regression analyses indicated that verbal IQ moderated the relationship between the DI construct of decision making and academic achievement. Self-reported school attendance and number of previous arrests did not significantly mediate the relationship between DI and academic achievement. These results may indicate that the decision-making factor of DI may be particularly important, and, if results are replicated, future intervention efforts could focus more on improving this skill within this juvenile justice population. Additionally, the overall importance of the full DI construct is an important area of future study.

Evidence of a Gene × Environment Interaction Between Birth Weight and Genetic Risk in the Prediction of Criminogenic Outcomes Among Adolescent Males

A number of studies have revealed that low birth weight children have a heightened risk of various maladaptive outcomes, including academic challenges and delinquent involvement. However, very little research to date has examined whether the relationship between low birth weight, poor academic performance, and delinquent peer affiliation is moderated by genetic risk. Using data from the National Longitudinal study of Adolescent Health, the present study examines whether male adolescents born at very low birth weights are significantly predisposed to poor academic performance and delinquent peer affiliation. Moreover, we test whether the effect of birth weight on these outcomes is conditioned by level of genetic risk. We find no evidence that very low birth weight males are more likely to affiliate with delinquent peers or perform poorly in school during adolescence. However, upon examining gene-environment interactions, we find that being born at a very low birth weight does significantly increase the odds of poor academic performance and delinquent peer affiliation among males who possess a higher level of genetic risk. Limitations are noted and the implications of the findings are discussed.

Developmental changes in genetic and environmental influences on rule-breaking and aggression: age and pubertal development

BACKGROUND

Antisocial behavior (ASB) can be meaningfully divided into nonaggressive rule-breaking versus aggressive dimensions, which differ in developmental course and etiology. Previous research has found that genetic influences on rule-breaking, but not aggression, increase from late childhood to mid-adolescence. This study tested the extent to which the developmental increase in genetic influence on rule-breaking was associated with pubertal development compared to chronological age.

METHOD

Child and adolescent twins (n = 1,031), ranging in age from 8 to 20 years (M age = 13.5 years), were recruited from public schools as part of the Texas Twin Project. Participants reported on their pubertal development using the Pubertal Development Scale and on their involvement in ASB on items from the Child Behavior Checklist. Measurement invariance of ASB subtypes across age groups (≤12 years vs. >12 years old) was tested using confirmatory factor analyses. Quantitative genetic modeling was used to test whether the genetic and environmental influences on aggression and rule-breaking were moderated by age, pubertal status, or both.

RESULTS

Quantitative genetic modeling indicated that genetic influences specific to rule-breaking increased as a function of pubertal development controlling for age (a gene × puberty interaction), but did not vary as a function of age controlling for pubertal status. There were no developmental differences in the genetic etiology of aggression. Family-level environmental influences common to aggression and rule-breaking decreased with age, further contributing to the differentiation between these subtypes of ASB from childhood to adolescence.

CONCLUSIONS

Future research should discriminate between alternative possible mechanisms underlying gene × puberty interactions on rule-breaking forms of antisocial behavior, including possible effects of pubertal hormones on gene expression.

Overlapping genetic and child-specific nonshared environmental influences on listening comprehension, reading motivation, and reading comprehension

This study investigated the genetic and environmental influences on observed associations between listening comprehension, reading motivation, and reading comprehension. Univariate and multivariate quantitative genetic models were conducted in a sample of 284 pairs of twins at a mean age of 9.81 years. Genetic and nonshared environmental factors accounted for statistically significant variance in listening and reading comprehension, and nonshared environmental factors accounted for variance in reading motivation. Furthermore, listening comprehension demonstrated unique genetic and nonshared environmental influences but also had overlapping genetic influences with reading comprehension. Reading motivation and reading comprehension each had unique and overlapping nonshared environmental contributions. Therefore, listening comprehension appears to be related to reading primarily due to genetic factors whereas motivation appears to affect reading via child-specific, nonshared environmental effects.

Comparing the Developmental Genetics of Cognition and Personality over the Life Span

Empirical studies of cognitive ability and personality have tended to operate in isolation of one another. We suggest that returning to a unified approach to considering the development of individual differences in both cognition and personality can enrich our understanding of human development. We draw on previous meta-analyses of longitudinal, behavior genetic studies of cognition and personality across the life span, focusing particular attention on age trends in heritability and differential stability. Both cognition and personality are moderately heritable and exhibit large increases in stability with age; however, marked differences are evident. First, the heritability of cognition increases substantially with child age, while the heritability of personality decreases modestly with age. Second, increasing stability of cognition with age is overwhelmingly mediated by genetic factors, whereas increasing stability of personality with age is entirely mediated by environmental factors. Third, the maturational time-course of stability differs: Stability of cognition nears its asymptote by the end of the first decade of life, whereas stability of personality takes three decades to near its asymptote. We discuss how proximal gene-environment dynamics, developmental processes, broad social contexts, and evolutionary pressures may intersect to give rise to these divergent patterns.

A Hierarchical Factor Model of Executive Functions in Adolescents: Evidence of Gene-Environment Interplay

Executive functions (EF) are a complex set of neurodevelopmental, higher-ordered processes that are especially salient during adolescence. Disruptions to these processes are predictive of psychiatric problems in later adolescence and adulthood. The objectives of the current study were to characterize the latent structure of EF using bifactor analysis and to investigate the independent and interactive effects of genes and environments on EF during adolescence. Using a representative young adolescent sample, we tested the interaction of a polymorphism in the serotonin transporter gene (5-HTTLPR) and parental supervision for EF through hierarchical linear regression. To account for the possibility of a hierarchical factor structure for EF, a bifactor analysis was conducted on the eight subtests of the Delis-Kaplan Executive Functions System (D-KEFS). The bifactor analysis revealed the presence of a general EF construct and three EF subdomains (i.e., conceptual flexibility, inhibition, and fluency). A significant 5-HTTLPR by parental supervision interaction was found for conceptual flexibility, but not for general EF, fluency or inhibition. Specifically, youth with the L/L genotype had significantly lower conceptual flexibility scores compared to youth with S/S or S/L genotypes given low levels of parental supervision. Our findings indicate that adolescents with the L/L genotype were especially vulnerable to poor parental supervision on EF. This vulnerability may be amenable to preventive interventions.

Gross domestic product, science interest, and science achievement: a person × nation interaction

Maximizing science achievement is a critical target of educational policy and has important implications for national and international economic and technological competitiveness. Previous research has identified both science interest and socioeconomic status (SES) as robust predictors of science achievement, but little research has examined their joint effects. In a data set drawn from approximately 400,000 high school students from 57 countries, we documented large Science Interest × SES and Science Interest × Per Capita Gross Domestic Product (GDP) interactions in the prediction of science achievement. Student interest in science is a substantially stronger predictor of science achievement in higher socioeconomic contexts and in higher-GDP nations. Our results are consistent with the hypothesis that in higher-opportunity contexts, motivational factors play larger roles in learning and achievement. They add to the growing body of evidence indicating that substantial cross-national differences in psychological effect sizes are not simply a logical possibility but, in many cases, an empirical reality.

Does learning to read improve intelligence? A longitudinal multivariate analysis in identical twins from age 7 to 16

Evidence from twin studies points to substantial environmental influences on intelligence, but the specifics of this influence are unclear. This study examined one developmental process that potentially causes intelligence differences: learning to read. In 1,890 twin pairs tested at 7, 9, 10, 12, and 16 years, a cross-lagged monozygotic-differences design was used to test for associations of earlier within-pair reading ability differences with subsequent intelligence differences. The results showed several such associations, which were not explained by differences in reading exposure and were not restricted to verbal cognitive domains. The study highlights the potentially important influence of reading ability, driven by the nonshared environment, on intellectual development and raises theoretical questions about the mechanism of this influence.

Continuity of genetic and environmental influences on cognition across the life span: a meta-analysis of longitudinal twin and adoption studies

The longitudinal rank-order stability of cognitive ability increases dramatically over the life span. Theoretical perspectives differ in their emphasis on genetic mechanisms in explaining the longitudinal stability of cognition and how stability changes with development. However, the patterns of stability of genetic and environmental influences on cognition over the life span remain poorly understood. We searched for longitudinal studies of cognition that reported raw genetically informative longitudinal correlations or parameter estimates from longitudinal behavior genetic models. We identified 150 combinations of time points and measures from 15 independent longitudinal samples. In total, longitudinal data came from 4,548 monozygotic twin pairs raised together, 7,777 dizygotic twin pairs raised together, 34 monozygotic twin pairs raised apart, 78 dizygotic twin pairs raised apart, 141 adoptive sibling pairs, and 143 nonadoptive sibling pairs, ranging in age from infancy through late adulthood. At all ages, cross-time genetic correlations and shared environmental correlations were substantially larger than cross-time nonshared environmental correlations. Cross-time correlations for genetic and shared environmental components were, respectively, low and moderate during early childhood, increased sharply over child development, and remained high from adolescence through late adulthood. Cross-time correlations for nonshared environmental components were low across childhood and gradually increased to moderate magnitudes in adulthood. Increasing phenotypic stability over child development was almost entirely mediated by genetic factors. Time-based decay of genetic and shared environmental stability was more pronounced earlier in child development. Results are interpreted in reference to theories of gene-environment correlation and interaction.

A biopsychosocial perspective on parenting and developmental psychopathology

Although considerable research has examined the relations between parental behavior and a range of child developmental outcomes, much of this work has been conducted at a very broad level of behavioral analysis. A developmental psychopathology framework and recent research conducted within this framework point to the need for models of parenting and child psychopathology that offer greater specificity regarding processes that may be implicated in the effects of these relationships. In addition, recent animal work and some human work has focused more on theproximalbiological and social mechanisms through which parenting affects child outcomes. Our conceptualization of parenting effects acknowledges that family and child factors are embedded in a dynamic biological and social context that is key to understanding developmental trajectories of child adjustment. In this paper, we review two areas of research that are illuminating the biological processes underlying links between parenting and child psychopathology: molecular genetics and psychophysiology. We adopt a biopsychosocial perspective on developmental psychopathology that implies that a set of hierarchically organized, but reciprocally interacting, processes, from the genetic to the environmental, provide the essential elements of both normative and nonnormative development (Gottlieb, 2007). New directions stimulated by this general approach are discussed, with an emphasis on the contextual and developmental issues and applications implied by such a perspective.

Academic achievement as a moderator of genetic influences on alcohol use in adolescence

Prior research suggests a link between academic performance and alcohol use during adolescence, but the degree to which this association reflects actual protective effects continues to be debated. We investigated the role of genetic factors in the association between academic achievement and adolescent alcohol use and whether achievement might constrain the translation of genetic influences on drinking into actual behavior (a Gene × Environment interaction). Analysis of twin data from Add Health (n = 399 monozygotic and dizygotic twin pairs) revealed not only common genetic factors underlying the association between achievement and alcohol consumption but also evidence for a gene-environment interaction. Specifically, the protective effect of achievement operated by moderating heritability of alcohol use, which was particularly salient for adolescents at high genetic risk for alcohol use.

Genetic and Environmental Influences on Cognition Across Development and Context

Genes account for between approximately 50% and 70% of the variation in cognition at the population level. However, population-level estimates of heritability potentially mask marked subgroup differences. We review the body of empirical evidence indicating that (a) genetic influences on cognition increase from infancy to adulthood, and (b) genetic influences on cognition are maximized in more advantaged socioeconomic contexts (i.e., a Gene × Socioeconomic Status interaction). We discuss potential mechanisms underlying these effects, particularly transactional models of cognitive development. Transactional models predict that people in high-opportunity contexts actively evoke and select positive learning experiences on the basis of their genetic predispositions; these learning experiences, in turn, reciprocally influence cognition. The net result of this transactional process is increasing genetic influence with increasing age and increasing environmental opportunity.

Explaining the increasing heritability of cognitive ability across development: a meta-analysis of longitudinal twin and adoption studies

Genes account for increasing proportions of variation in cognitive ability across development, but the mechanisms underlying these increases remain unclear. We conducted a meta-analysis of longitudinal behavioral genetic studies spanning infancy to adolescence. We identified relevant data from 16 articles with 11 unique samples containing a total of 11,500 twin and sibling pairs who were all reared together and measured at least twice between the ages of 6 months and 18 years. Longitudinal behavioral genetic models were used to estimate the extent to which early genetic influences on cognition were amplified over time and the extent to which innovative genetic influences arose with time. Results indicated that in early childhood, innovative genetic influences predominate but that innovation quickly diminishes, and amplified influences account for increasing heritability following age 8 years.

Socioeconomic Status Modifies Interest-Knowledge Associations among Adolescents

Researchers have recently taken a renewed interest in examining the patterns by which noncognitive traits and cognitive traits relate to one another. Few researchers, however, have examined the possibility that such patterns might differ according to environmental context. Using data from a nationally representative sample of approximately 375,000 students from 1,300 high schools in the United States, we examined the relations between socioeconomic status (SES), interests, and knowledge in eleven academic, vocational/professional, and recreational domains. We found little support for the hypothesis that SES-related differences in levels of interest mediate SES-related differences in levels of knowledge. In contrast, we found robust and consistent support for the hypothesis that SES moderates interest-knowledge associations. For 10 out of 11 of the knowledge domains examined, the interest-knowledge association was stronger for individuals living in higher SES contexts. Moderation persisted after controlling for an index of general intelligence. These findings are consistent with the hypothesis that low SES inhibits individuals from selectively investing their time and attention in learning experiences that are consistent with their interests.

Correlated longitudinal changes across linguistic, achievement, and psychomotor domains in early childhood: evidence for a global dimension of development

An important question within developmental psychology concerns the extent to which the maturational gains that children make across multiple diverse domains of functioning can be attributed to global (domain-general) developmental processes. The present study investigated this question by examining the extent to which individual differences in change across children's development in five different domains are correlated. Multivariate growth-curve models were fit to longitudinal data on linguistic, mathematics, reading, gross motor, and fine motor skills in 8950 children ranging in age from 44 to 86 months (3.7 years to 7.2 years). All five rates of change were positively intercorrelated. A common factor accounted for 42% of the individual differences in change. These results suggest that a global dimension underlies substantial proportions of cognitive and psychomotor development.

Learning Motivation Mediates Gene-by-Socioeconomic Status Interaction on Mathematics Achievement in Early Childhood

There is accumulating evidence that genetic influences on achievement are more pronounced among children living in higher socioeconomic status homes, and that these gene-by-environment interactions occur prior to children's entry into formal schooling. We hypothesized that one pathway through which socioeconomic status promotes genetic influences on early achievement is by facilitating the processes by which children select, evoke, and attend to learning experiences that are consistent with genetically influenced individual differences in their motivation to learn. We examined this hypothesis in a nationally representative sample of approximately 650 pairs of four-year old identical and fraternal twins who were administered a measure of math achievement, and rated by their parents on a broad set of items assessing learning motivation. Results indicated a genetic link between learning motivation and math achievement that varied positively with family socioeconomic status: Genetic differences in learning motivation contributed to math achievement more strongly in more advantaged homes. Once this effect of learning motivation was controlled for, gene-by-socioeconomic status interaction on math achievement was reduced from previously significant levels, to nonsignificant levels.