Genes Unite Executive Functions in Childhood

Cognitive, Intervention, and Neuroimaging Perspectives on Executive Function in Children With Reading Disabilities

The role of executive function (EF) in the reading process, and in those with reading difficulties, remains unclear. As members of the Texas Center for Learning Disabilities, we review multiple perspectives regarding EF in reading and then summarize some of our recent studies of struggling and typical readers in grades 3-5. Study 1a found that a bi-factor structure best represented a comprehensive assessment of EF. Study 1b found that cognitive and behavioral measures of EF related independently to math and reading. Study 1c found that EF related to reading, above and beyond other variables, but Study 1d found no evidence that adding an EF training component improved intervention response. Study 1e found that pretest EF abilities did not relate to intervention response. Neuroimaging studies examined EF-related brain activity during both reading and nonlexical EF tasks. In Study 2a, the EF task evoked control activity, but generated no differences between struggling and typical readers. The reading task, however, had group differences in both EF and reading regions. In Study 2b, EF activity during reading at pretest was related to intervention response. Across studies, EF appears involved in the reading process. There is less evidence for general EF predicting or improving intervention outcomes.

Physical and Cultural Inheritance Enhance Agency, but What are the Origins of this Concern to Establish a Legacy? A Nationally-Representative Twin Study of Erikson's Concept of Generativity

Generativity-showing concern to establish and guide future generations-has been argued to be a biological adaptation central to cumulative culture and survival, but also, in turn, to be a cultural adaptation dependent on norms. From the perspective of human agency, concern for the future has played a key role in raising agency for generations that follow by creating infrastructure and cultural inheritance. Here, in a population-representative sample of 756 twin-pairs, we present the first test of the genetic and environmental structure of generativity using the Loyola Generativity Scale (short). Genetic analysis of scale sum-scores revealed that shared environmental effects were comparable in magnitude or exceeded effects estimated for genetic differences (A = 0.30 CI95 [- 0.01, 0.61], C = 0.41 [0.25, 0.56], E = 0.86 [0.79, 0.93]). At the item level, a well-fitting genetically-informed model suggested 3 factors influencing generativity via a common-pathway structure. The first was tentatively characterized as reflecting a heritable general concern for the future. The second reflected being a valued source of advice and assistance. The third factor showed only unique environment effects and had as its strongest indicator having had a good influence on the lives of others. Replicability of this structure should be tested in the full version of the scale. Work is needed also to validate influences of generativity on vocations such as teaching and on philanthropic activity improving life for subsequent generations.

Parental predictors of children's executive functioning from ages 6 to 10

According to prominent models of child development, parental factors may contribute to individual differences in children's executive functioning (EF). Here, we examine the relative importance of parents' socio-economic status, mental health, and parenting as predictors of EF development, drawing on a large (n = 1,070) community sample of Norwegian children who received biennial EF assessments from 6 to 10 years of age. We measure EF by means of the Behavior Rating Inventory of Executive Function. We assess parenting through observer ratings of parent-child interactions and parental mental health via the Beck Anxiety Inventory, Beck Depression Inventory, and Hopkins Symptom Checklist. When we adjust for all time-invariant unmeasured confounders, higher parental education predicts superior EF development, whereas harsh parenting forecasts poorer EF development. However, parenting does not mediate the effect of parental education. These results indicate that harsh parenting should be targeted in interventions aimed at improving EF. Statement of contribution What is already known on this subject? Parental factors seem to affect child development of executive functions (EF). Specifically, parental socio-economic status, mental health, and their parenting seem to influence the developmental course of child EF. What does this study add? To what degree the parental influence on EF development is likely to be driven by time-invariant factors, for example, genetics. The relative influence of positive and negative parenting on EF development.

Lower general executive function is primarily associated with trait worry: A latent variable analysis of negative thought/affect measures

This exploratory latent-variable study sought to identify common sources of variance between two multifaceted sets of constructs: executive functions (EFs) and negative thoughts/affect. One-hundred ninety-two college students completed nine tasks representing three types of EFs (inhibition, updating, and shifting) and a set of questionnaires assessing four facets of negative thought/affect (anxiety symptoms, depression symptoms, worry, and rumination). Results indicated that, although the four negative thought/affect constructs were substantially correlated with one another, trait worry was the construct uniquely associated with EFs. Specifically, worry was associated with general EF abilities underlying all three subtypes of EFs (common EF), but was not associated with specific EF abilities (i.e., shifting-specific and updating-specific). These findings highlight the importance of partitioning common and specific variances in both EFs and negative thought/affect when examining the associations between these two research domains. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Understanding Emotion Inflexibility in Risk for Affective Disease: Integrating Current Research and Finding a Path Forward

Emotion-related disorders (e.g., depression, anxiety, stress, eating, substance and some personality disorders) include some of the most common, burdensome, and costly diseases worldwide. Central to many, if not all of these disorders, may be patterns of rigid or inflexible emotion responses. Indeed, theorists point to emotion in-flexibility as a potential cause or maintaining factor in emotion-related diseases. Despite the increasing prominence of emotion inflexibility in theories of affective disease, a comprehensive review of the developing empirical literature has not yet been conducted. Accordingly, this review will examine the three dominant lines of inquiry assessing emotion flexibility. These include: (1) the capacity to use and vary deliberate emotion regulation strategies, (2) the context sensitivity of spontaneous emotional responses, and (3) flexibility in the appraisal of emotional events and experiences. Moreover, current evidence suggests that each of these three lines of research may converge to suggest the interplay of two key biological dimensions in emotion inflexibility, threat sensitivity, and cognitive control, known to be impaired in patients with affective disorders. In short, this developing body of work suggests a path by which future research could explicate and even exploit the ties between emotion inflexibility and affective disease, contributing to the development of improved models of risk, assessment, and intervention, with broad implications for psychological health.

Genetic and Environmental Associations Among Executive Functions, Trait Anxiety, and Depression Symptoms in Middle Age

Multiple executive functions (EFs) are associated with trait anxiety and depression symptoms, but it is unclear how genetic and/or environmental factors account for these associations, and if they are explained by general variance underlying multiple EFs (i.e., Common EF). In this study, 1207 male twins completed seven EF tasks and measures of trait anxiety and depression symptoms at average age 62. The Common EF factor was associated with both anxiety (r= -.25) and depression symptoms (r= -.35). Anxiety and depression had near complete genetic overlap (r g=.96). Genetic influences shared with depression accounted for 83% of the phenotypic correlation between anxiety and Common EF. For depression, the phenotypic correlation with Common EF was explained by genetic influences shared with anxiety (69%), but also nonshared environmental influences distinct from anxiety (20%). These results suggest that genetic influences on Common EF play a role in the observed genetic overlap between anxiety and depression.

Genetic and environmental relations of executive functions to antisocial personality disorder symptoms and psychopathy

Meta-analytic findings suggest that antisocial behavior, broadly defined, may relate to a Common Executive Function (EF) factor that captures covariance across response inhibition, working memory updating, and mental set shifting tasks. However, it is unclear whether this common factor, which is isomorphic with individual differences in response inhibition, accounts for all of the EF variance in antisocial behavior and psychopathy, or if they also relate to updating- and shifting-specific abilities. Moreover, findings that antisocial behavior and lower cognitive ability are particularly associated with the psychopathy dimension reflecting impulsivity and irresponsibility, compared to the dimension reflecting affective-interpersonal functioning, raise the possibility that EF relates to the variance shared between the impulsive-irresponsible psychopathy dimension and antisocial personality disorder. We examined these questions in a young adult twin sample (N = 765) with measures of multiple EF latent variables, Levenson Self-Report Psychopathy (LSRP) Primary (affective-interpersonal) and Secondary (impulsive-irresponsible) scales, and antisocial personality disorder symptoms (ASPDsx). Phenotypically, higher ASPDsx and LSRP Secondary psychopathy, but not LSRP Primary psychopathy, were associated with lower Common EF. Moreover, both psychopathy dimensions were negatively correlated with Updating-Specific ability, which was unrelated to ASPDsx. Results from twin models indicated that the association between LSRP Secondary psychopathy and ASPDsx was due to both genetic and nonshared environmental influences; however, Common EF's association with ASPDsx was primarily genetic, whereas its association with LSRP Secondary psychopathy had a significant environmental component. Thus, the interrelations among these constructs may reflect heterogeneous etiological pathways.

"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).

What's going on in my baby's mind? Mothers' executive functions contribute to individual differences in maternal mentalization during mother-infant interactions

Maternal mentalization refers to a mother's capacity to understand mental-states of herself and her child and to regard her child as a psychological agent. In mother-infant interactions, this capacity is commonly conceptualized as maternal mind-mindedness, which can be divided into two dimensions: appropriate and nonattuned interpretations of the infants' mental-states. Appropriate mind-mindedness refers to interpretations that seem to be compatible with the infant's behaviors, whereas nonattuned mind-mindedness refers to noncompatible interpretations. The aim of this study was to investigate the cognitive mechanisms that contribute to mind-mindedness. Specifically, we investigated the role of executive functions in appropriate and nonattuned mind-mindedness, and the moderating roles of two infant-related factors, prematurity (as a stressful context) and child temperament (as a context of unpredictability and negative emotionality). To this end, mother-infant free play interactions were coded for mind-mindedness in a sample of 102 mothers and their 6-month-old infants (61 preterm, 41 full-term). When children were 66-months old, mothers completed cognitive tasks that assessed working memory updating, resistance to interference, response inhibition, and shifting. Appropriate mind-mindedness was positively associated with updating, and this link was stronger when infant temperament was rated as more difficult. Furthermore, among mothers of full-term infants, mothers' resistance to interference was negatively associated with nonattuned mind-mindedness. This link was not evident in the stressful context of premature birth. Mothers' response inhibition and shifting were not associated with either of the mind-mindedness dimensions. Implications on understanding variability in maternal mentalization during mother-infant interactions and the roles of executive functions in parenting are discussed.

Predictors of Executive Functions in Preschoolers: Findings From the SPLASHY Study

Executive functions (EFs) have been reported to play a crucial role in children's development, affecting their academic achievement, health, and quality of life. This study examined individual and interpersonal predictors for EFs in 555 typically developing preschool children aged 2-6 years. Children were recruited from 84 child care centers in the German- and French-speaking parts of Switzerland within the Swiss Preschoolers' Health Study (SPLASHY). A total of 20 potential predictors were assessed at the first measurement (T1). These included eight demographic/biological predictors, such as socioeconomic status, preterm birth, physical activity, and motor skills; six psychological predictors, such as hyperactivity, visual perception, and emotionality; and six interpersonal predictors, such as parenting style and stress, presence of siblings, and days spent in the child care center. The predictive value of these variables on EFs 1 year later (T2) was assessed using both standard multiple regression analysis and penalized regression to avoid overfitting due to the number of potential predictors. Female sex (β = 0.14), socio-economic status (β = 0.15), fine motor skills (β = 0.17), visual perception at T1 (β = 0.16), and EFs at T1 (β = 0.30) were all associated with EFs at T2, exhibiting small to medium effect sizes. All predictors together accounted for 31% of the variability in EFs. However, none of the interpersonal predictors were significant. Thus, we conclude that most of the factors that can predict EFs in preschool age are individual variables, and these tend to be more difficult to influence than interpersonal factors. In fact, children from families with low socio-economic status may be particularly vulnerable to poor EFs. Furthermore, encouraging fine motor skills early in life may support the development of EFs.

The neural architecture of executive functions is established by middle childhood

Executive functions (EFs) are regulatory cognitive processes that support goal-directed thoughts and behaviors and that involve two primary networks of functional brain activity in adulthood: the fronto-parietal and cingulo-opercular networks. The current study assessed whether the same networks identified in adulthood underlie child EFs. Using task-based fMRI data from a diverse sample of N = 117 children and early adolescents (M age = 10.17 years), we assessed the extent to which neural activity was shared across switching, updating, and inhibition domains, and whether these patterns were qualitatively consistent with adult EF-related activity. Brain regions that were consistently engaged across switching, updating, and inhibition tasks closely corresponded to the cingulo-opercular and fronto-parietal networks identified in studies of adults. Isolating brain activity during more demanding task periods highlighted contributions of the dorsal anterior cingulate and anterior insular regions of the cingulo-opercular network. Results were independent of age and time-on-task effects. These results indicate that the two core brain networks that support EFs are in place by middle childhood, in agreement with resting-state findings of adultlike brain network organization. Improvement in EFs from middle childhood to adulthood, therefore, are likely due to quantitative changes in activity within these networks, rather than qualitative changes in the organization of the networks themselves. Improved knowledge of how the brain's functional organization supports EF in childhood has critical implications for understanding the maturation of cognitive abilities.

Possible requirement of executive functions for high performance in soccer

In open-skill sports such as soccer, the environment surrounding players is rapidly changing. Therefore, players are required to process a large amount of external information and take appropriate actions in a very short period. Executive functions (EFs)-the cognitive control processes that regulate thoughts and action-are needed for high performance in soccer. In this study, we measured the EFs of young soccer players aged 8-11 years, who were applying for admission to an elite youth program of a Japanese Football League club. We found that even though admission was determined by the soccer performance of the players, significant differences were observed between players who were approved and those who were not approved into the program. Soccer players who had been approved into the program got higher scores in general EFs tests than those who had been rejected. Our results proposed that measuring EFs provides coaches with another objective way to assess the performance levels of soccer players.

Contributions of mothers' and fathers' parenting to children's self-regulation: Evidence from an adoption study

The origins of top-down self-regulation are attributed to genetic and socialization factors as evidenced by high heritability estimates from twin studies and the influential role of parenting. However, recent evidence suggests that parenting behavior itself is affected by parents' own top-down self-regulation. Because children's top-down self-regulation is influenced by genetic factors and parenting is influenced by top-down self-regulation, the effects of parenting on children's top-down self-regulation identified in prior studies may partially reflect passive gene-environment correlation. The goal of this study was to examine parenting influences on children's top-down self-regulation using a longitudinal, adoption-at-birth design, a method of identifying parenting influences that are independent of the role of shared genetic influences on children's characteristics because adoptive parents are genetically unrelated to their adopted child. Participants (N = 361) included adoptive families and biological mothers of adopted children. Adoptive mothers' and fathers' harsh/negative parenting were assessed when children were 27 months of age and biological mothers' top-down self-regulation was assessed when children were 54 months of age. Adopted children's top-down self-regulation was assessed when they were 54 and 72 months of age. Results, accounting for child gender, biological mother top-down self-regulation, and the potential evocative effects of adopted child anger, provide evidence that inherited influences and socialization processes uniquely contribute to children's top-down self-regulation. Furthermore, findings demonstrate the importance of both mother's and father's parenting behavior as an influence on young children's top-down self-regulation. The implications of these findings for understanding the complex mechanisms that influence children's top-down self-regulation are discussed.

Longitudinal Relations Between Depressive Symptoms and Executive Functions From Adolescence to Early Adulthood: A Twin Study

Depression is associated with deficits in executive functions (EFs)-cognitive control abilities that regulate goal-directed thoughts and actions-but the etiology of these associations is unclear. We examined the relations between depressive symptoms and multiple EF latent variables in a population-based sample of 439 twin pairs assessed at mean ages 12, 17, and 23 years. Greater depressive symptoms negatively related to a Common EF factor capturing shared variance across response inhibition, working memory updating, and mental set shifting tasks, and also negatively related to an Updating-Specific factor, but not a Shifting-Specific factor. Cross-lagged panel models suggested that the Common EF correlations reflected within-wave associations rather than prospective effects, whereas the Updating-Specific correlations reflected associations of earlier depression levels with later Updating-Specific ability. Twin models were consistent with a model in which Common EF and Updating-Specific abilities relate to depression through correlated genetic risk, with no significant environmental correlations.

A meta-analysis of the relationship between socioeconomic status and executive function performance among children

The relationship between childhood socioeconomic status (SES) and executive function (EF) has recently attracted attention within psychology, following reports of substantial SES disparities in children's EF. Adding to the importance of this relationship, EF has been proposed as a mediator of socioeconomic disparities in lifelong achievement and health. However, evidence about the relationship between childhood SES and EF is mixed, and there has been no systematic attempt to evaluate this relationship across studies. This meta-analysis systematically reviewed the literature for studies in which samples of children varying in SES were evaluated on EF, including studies with and without primary hypotheses about SES. The analysis included 8760 children between the ages of 2 and 18 gathered from 25 independent samples. Analyses showed a small but statistically significant correlation between SES and EF across all studies (rrandom  = .16, 95% CI [.12, .21]) without correcting for attenuation owing to range restriction or measurement unreliability. Substantial heterogeneity was observed among studies, and a number of factors, including the amount of SES variability in the sample and the number of EF measures used, emerged as moderators. Using only the 15 studies with meaningful SES variability in the sample, the average correlation between SES and EF was small-to-medium in size (rrandom  = .22, 95% CI [.17, .27]). Using only the six studies with multiple measures of EF, the relationship was medium in size (rrandom  = .28, 95% CI [.18, .37]). In sum, this meta-analysis supports the presence of SES disparities in EF and suggests that they are between small and medium in size, depending on the methods used to measure them.

Stability of genetic and environmental influences on executive functions in midlife

Research on executive functions (EFs) has revealed that individual differences in general EF abilities are highly correlated across the first few decades of life, especially at the level of genetic influences. Our work has also provided evidence for substantial heritability of this Common EF factor in midlife, but it remains unclear whether individual differences in Common EFs continue to show strong stability in middle age. We examined data from 1,464 middle-aged twins from the Vietnam Era Twin Study of Aging, most of whom completed 7 neuropsychological measures of EFs at 2 points in middle age (M_ages = 56 and 62). Confirmatory factor analysis indicated that individual differences in Common EF, a latent factor explaining variation in seven neuropsychological EF tasks, were highly correlated across this 6-year period (r = .97), and that the same genetic and environmental influences were operating across this interval (genetic and shared environmental correlations = 1.0, nonshared environment correlation = .95). Similar phenotypic and genetic stability was observed for a Working Memory (WM)-Specific latent factor, which explained additional variance in working memory span tasks not captured by Common EF (r = .98, genetic correlation = 1.0, nonshared environmental correlation = .88). There was a large mean-level performance decline in Common EF (d = -.60) but not WM-Specific (d = -.03). These results suggest that there is substantial decline in Common EF abilities across middle age but that individual differences are almost perfectly stable. (PsycINFO Database Record

Cognitive genomics: Searching for the genetic roots of neuropsychological functioning

OBJECTIVE

Human cognition has long been known to be under substantial genetic control. With the complete mapping of the human genome, genome-wide association studies for many complex traits have proliferated; however, the highly polygenic nature of intelligence has made the identification of the precise genes that influence both global and specific cognitive abilities more difficult than anticipated.

METHOD

Here, we review the latest developments in the genomics of cognition, including a discussion of methodological advances in the genetic analysis of complex traits, and shared genetic contributions to cognitive abilities and neuropsychiatric disorders.

RESULTS

A wealth of twin and family studies have provided compelling evidence for a strong heritable component of both global and specific cognitive abilities, and for the existence of "generalist genes" responsible for a large portion of the variance in diverse cognitive abilities. Increasingly sophisticated analytic tools and ever-larger sample sizes are now facilitating the identification of specific genetic and molecular underpinnings of cognitive abilities, leading to optimism regarding possibilities for novel treatments for illnesses related to cognitive function.

CONCLUSIONS

We conclude with a set of future directions for the field, which will further accelerate discoveries regarding the biological pathways relevant to cognitive abilities. These, in turn, may be further interrogated in order to link biological mechanisms to behavior. (PsycINFO Database Record

Genetic and environmental influences on household financial distress

Heterogeneity of household financial outcomes emerges from various individual and environmental factors, including personality, cognitive ability, and socioeconomic status (SES), among others. Using a genetically informative data set, we decompose the variation in financial management behavior into genetic, shared environmental and non-shared environmental factors. We find that about half of the variation in financial distress is genetically influenced, and personality and cognitive ability are associated with financial distress through genetic and within-family pathways. Moreover, genetic influences of financial distress are highest at the extremes of SES, which in part can be explained by neuroticism and cognitive ability being more important predictors of financial distress at low and high levels of SES, respectively.

Genetic and environmental architecture of executive functions in midlife

OBJECTIVE

Research on executive functions (EFs) has revealed evidence for general abilities that underlie performance across multiple EF tasks and domains. This Common EF factor is highly stable in adolescence through young adulthood, correlates with other important cognitive abilities, and is explained largely by genetic influences. However, little is known about Common EF beyond young adulthood. This study examines 3 hypotheses regarding the latent structure, genetic/environmental etiology, and cognitive correlates of Common EF in middle age.

METHOD

We examined data from 1,284 middle-aged twins (51-60 years) in the Vietnam Era Twin Study of Aging who completed 7 neuropsychological measures of EFs, as well as measures of general cognitive ability and processing speed.

RESULTS

Our confirmatory factor analysis indicated that Common EF explained variation across all 7 EF tasks. Inhibition and shifting were subsumed entirely under the Common EF factor, and there was an additional working memory span-specific factor. Common EF was heritable in midlife (a2 = .46), with additional evidence for both shared environmental influences (c2 = .41) and nonshared environmental influences (e2 = .13). Higher Common EF was moderately associated with higher general cognitive ability, measured both in early adulthood and midlife, and faster processing speed in midlife. These correlations were primarily driven by shared genetic influences.

CONCLUSIONS

These results support the hypothesis that Common EF captures similar EF abilities in midlife as in adolescence and young adulthood. However, environmental influences may explain a larger portion of variance in this construct as individuals age. (PsycINFO Database Record

Beyond dual systems: A genetically-informed, latent factor model of behavioral and self-report measures related to adolescent risk-taking

The dual systems model posits that adolescent risk-taking results from an imbalance between a cognitive control system and an incentive processing system. Researchers interested in understanding the development of adolescent risk-taking use a diverse array of behavioral and self-report measures to index cognitive control and incentive processing. It is currently unclear whether different measures commonly interpreted as indicators of the same psychological construct do, in fact, tap the same underlying dimension of individual differences. In a diverse sample of 810 adolescent twins and triplets (M age=15.9years, SD=1.4years) from the Texas Twin Project, we investigated the factor structure of fifteen self-report and task-based measures relevant to adolescent risk-taking. These measures can be organized into four factors, which we labeled premeditation, fearlessness, cognitive dyscontrol, and reward seeking. Most behavioral measures contained large amounts of task-specific variance; however, most genetic variance in each measure was shared with other measures of the corresponding factor. Behavior genetic analyses further indicated that genetic influences on cognitive dyscontrol overlapped nearly perfectly with genetic influences on IQ (rA=-0.91). These findings underscore the limitations of using single laboratory tasks in isolation, and indicate that the study of adolescent risk taking will benefit from applying multimethod approaches.

Does One Year of Schooling Improve Children's Cognitive Control and Alter Associated Brain Activation?

The "5-to-7-year shift" refers to the remarkable improvements observed in children's cognitive abilities during this age range, particularly in their ability to exert control over their attention and behavior-that is, their executive functioning. As this shift coincides with school entry, the extent to which it is driven by brain maturation or by exposure to formal schooling is unclear. In this longitudinal study, we followed 5-year-olds born close to the official cutoff date for entry into first grade and compared those who subsequently entered first grade that year with those who remained in kindergarten, which is more play oriented. The first graders made larger improvements in accuracy on an executive-function test over the year than did the kindergartners. In an independent functional MRI task, we found that the first graders, compared with the kindergartners, exhibited a greater increase in activation of right posterior parietal cortex, a region previously implicated in sustained attention; increased activation in this region was correlated with the improvement in accuracy. These results reveal how the environmental context of formal schooling shapes brain mechanisms underlying improved focus on cognitively demanding tasks.

How Can Genetically Informed Research Help Inform the Next Generation of Interparental and Parenting Interventions?

There is robust evidence that the interparental relationship and parenting behaviors each have a significant influence on children's risk for emotional (internalizing) and behavioral (externalizing) problems. Indeed, interventions targeting the interparental relationship and parenting processes show significant intervention-related reductions in child internalizing and externalizing problems. However, most evidence-based parenting- and couple-focused interventions result in small to medium effects on children's emotional and behavior problems. It is proposed that there is opportunity to improve upon these interventions through incorporation of knowledge from quantitative genetic research. Three core recommendations are provided for practitioners engaging in intervention work with children and families. These recommendations are contextualized relative to what quantitative genetic studies can tell us about the role of the interparental relationship and parenting behaviors on child outcomes.

An Introduction to Cognitive Archaeology

Cognitive archaeology studies human cognitive evolution by applying cognitive-science theories and concepts to archaeological remains of the prehistoric past. After reviewing the basic epistemological stance of cognitive archaeology, this article illustrates this interdisciplinary endeavor through an examination of two of the most important transitions in hominin cognitive evolution—the appearance of Homo erectus about 2 million years ago, and the recent enhancement of working-memory capacity within the past 200,000 years. Although intentionally created stone tools date to about 3.3 million years ago, Homo erectus produced a bifacial, symmetrical handaxe whose design then persisted for nearly the next 2 million years. An enhancement in working-memory capacity may have been responsible for the relative explosion of culture within the past 50,000 years, which included personal ornamentation, highly ritualized burials, bow-and-arrow technology, depictive cave art, and artistic figurines.

Persistence and Fadeout in the Impacts of Child and Adolescent Interventions

Many interventions targeting cognitive skills or socioemotional skills and behaviors demonstrate initially promising but then quickly disappearing impacts. Our paper seeks to identify the key features of interventions, as well as the characteristics and environments of the children and adolescents who participate in them, that can be expected to sustain persistently beneficial program impacts. We describe three such processes: skill-building, foot-in-the-door and sustaining environments. We argue that skill-building interventions should target "trifecta" skills - ones that are malleable, fundamental, and would not have developed eventually in the absence of the intervention. Successful foot-in-the-door interventions equip a child with the right skills or capacities at the right time to avoid imminent risks (e.g., grade failure or teen drinking) or seize emerging opportunities (e.g., entry into honors classes). The sustaining environments perspective views high quality of environments subsequent to the completion of the intervention as crucial for sustaining early skill gains. These three perspectives generate both complementary and competing hypotheses regarding the nature, timing and targeting of interventions that generate enduring impacts.

Strong genetic overlap between executive functions and intelligence

Executive functions (EFs) are cognitive processes that control, monitor, and coordinate more basic cognitive processes. EFs play instrumental roles in models of complex reasoning, learning, and decision making, and individual differences in EFs have been consistently linked with individual differences in intelligence. By middle childhood, genetic factors account for a moderate proportion of the variance in intelligence, and these effects increase in magnitude through adolescence. Genetic influences on EFs are very high, even in middle childhood, but the extent to which these genetic influences overlap with those on intelligence is unclear. We examined genetic and environmental overlap between EFs and intelligence in a racially and socioeconomically diverse sample of 811 twins ages 7 to 15 years (M = 10.91, SD = 1.74) from the Texas Twin Project. A general EF factor representing variance common to inhibition, switching, working memory, and updating domains accounted for substantial proportions of variance in intelligence, primarily via a genetic pathway. General EF continued to have a strong, genetically mediated association with intelligence even after controlling for processing speed. Residual variation in general intelligence was influenced only by shared and nonshared environmental factors, and there remained no genetic variance in general intelligence that was unique of EF. Genetic variance independent of EF did remain, however, in a more specific perceptual reasoning ability. These results provide evidence that genetic influences on general intelligence are highly overlapping with those on EF. (PsycINFO Database Record

Unity and diversity of executive functions: Individual differences as a window on cognitive structure

Executive functions (EFs) are high-level cognitive processes, often associated with the frontal lobes, that control lower level processes in the service of goal-directed behavior. They include abilities such as response inhibition, interference control, working memory updating, and set shifting. EFs show a general pattern of shared but distinct functions, a pattern described as "unity and diversity". We review studies of EF unity and diversity at the behavioral and genetic levels, focusing on studies of normal individual differences and what they reveal about the functional organization of these cognitive abilities. In particular, we review evidence that across multiple ages and populations, commonly studied EFs (a) are robustly correlated but separable when measured with latent variables; (b) are not the same as general intelligence or g; (c) are highly heritable at the latent level and seemingly also highly polygenic; and (d) activate both common and specific neural areas and can be linked to individual differences in neural activation, volume, and connectivity. We highlight how considering individual differences at the behavioral and neural levels can add considerable insight to the investigation of the functional organization of the brain, and conclude with some key points about individual differences to consider when interpreting neuropsychological patterns of dissociation.

Stability and change in executive function abilities from late adolescence to early adulthood: A longitudinal twin study

Executive functions (EFs)-the higher level cognitive abilities that enable us to control our own thoughts and actions-continue to develop into early adulthood, yet no longitudinal study has examined their stability during the important life transition from late adolescence to young adulthood. In this twin study (total N = 840 individuals from 424 families), we examined the stability of individual differences in 3 EF components across a 6-year period, from approximately age 17 years (Wave 1) to 23 years (Wave 2). Specifically, we address the following questions: (a) How stable are individual differences in multiple EFs across this time period? and (b) What (genetic and/or environmental) influences affect stability and change in EFs? Results indicated that individual differences in EFs are quite stable across this 6-year period (phenotypic latent variable correlations ranged from 0.86 to 1.0). However, there was evidence for change, particularly in the factor common to multiple EFs (Common EF). Multivariate twin models suggested that stability was due almost entirely to high genetic correlations across time; there was no new genetic variance at Wave 2. Change in Common EF was due to small but significant nonshared environmental influences at Wave 2 (15%). The results suggest that individual differences in EFs are quite heritable and stable by late adolescence, yet are still sensitive to environmental influences.