Behavioral Genetic Perspective Research Articles

The Southern Illinois Twins/Triplets and Siblings Study (SITSS): A Longitudinal Study of Early Child Development.

This article reviews the Southern Illinois Twins/Triplets and Siblings Study (SITSS) and describes some of the findings related to recent projects that were completed using this sample. At this time, the SITSS has enrolled 375 twin pairs, 12 triplet families, 1 family of quadruplets, 98 nontwin sibling pairs and 287 singletons. Testing begins for twins and triplets as young as age 1 and then occurs yearly on their birthdays until 5 years of age. Through age 20, various follow-up studies have been conducted on the SITSS sample to examine their social, emotional, and cognitive development across childhood and adolescence from a behavioral genetic perspective. A variety of methodologies have been used to investigate gene-environment correlations (rGE) and gene-environment interactions (GxE). Advanced statistical procedures (e.g., genetic likelihood indices and multilevel modeling) have been utilized to further investigate genetic underpinnings of behavior. Recent results have indicated genetic influences on the aggressiveness of preschoolers' media preferences, increased problem behaviors related to young children's overestimation of self-competence, and the influence of early life temperament and internalizing problems on adolescent health behaviors. Additionally, the SITSS has provided evidence for evocative rGE for various behaviors (aggression, prosocial and play), as well as findings supporting interactions between the dopamine receptor D4 gene (DRD4) and the environment (peer victimization, prenatal birth complications and parental sensitivity). Together, by use of multitrait and multimethodological investigations, this behavior genetic data set assists in furthering our understanding of biological and environmental influences on children's development.

子どもによる親への対人的信頼感 : 児童・思春期の双生児を対象とした人間行動遺伝学的検討

子どもによる親への対人的信頼感 : 児童・思春期の双生児を対象とした人間行動遺伝学的検討

Test anxiety and a high-stakes standardized reading comprehension test: A behavioral genetics perspective.

Past research suggests that reading comprehension test performance does not rely solely on targeted cognitive processes such as word reading, but also on other non-target aspects such as test anxiety. Using a genetically sensitive design, we sought to understand the genetic and environmental etiology of the association between test anxiety and reading comprehension as measured by a high-stakes test. Mirroring the behavioral literature of test anxiety, three different dimensions of test anxiety were examined in relation to reading comprehension, namely intrusive thoughts, autonomic reactions, and off-task behaviors. Participants included 426 sets of twins from the Florida Twin Project on Reading. The results indicated test anxiety was negatively associated with reading comprehension test performance, specifically through common shared environmental influences. The significant contribution of test anxiety to reading comprehension on a high-stakes test supports the notion that non-targeted factors may be interfering with accurately assessing students' reading abilities.

Cognitive, Noncognitive, and Family Background Contributions to College Attainment: A Behavioral Genetic Perspective.

There is considerable evidence that college attainment is associated with family background and cognitive and noncognitive skills. Behavioral genetic methods are used to determine whether the family background effect is mediated through cognitive and noncognitive skill development. We analyze data from two longitudinal behavioral genetic studies: the Minnesota Twin Family Study, consisting of 1,382 pairs of like-sex twins and their parents, and the Sibling Interaction and Behavior Study, consisting of 409 adoptive and 208 nonadoptive families with two offspring and their rearing parents. Cognitive ability, noncognitive skills, and family background are all associated with offspring college attainment. Biometric analysis shows that the intergenerational transmission of college attainment owes to both genetic and shared environmental factors. The shared environmental influence was not due to highly educated parents fostering noncognitive skill development in their children, and there was limited evidence that they foster cognitive skill development. The environmental transmission of educational attainment does not appear to be a consequence of highly educated parents fostering cognitive and noncognitive skill development. Alternative mechanisms are needed to explain the strong shared environmental influence on college attainment. Possibilities include academic expectations, social network effects, and the economic benefits of having wealthy parents.

Emerging Trends in Behavioral Genetic Studies of Child Temperament.

In this article, we describe three emerging trends in the application of behavioral genetic methods to the study of temperament. The trends-using multiple methods to assess temperament, considering contextual influences on temperament, and evaluating the structure of temperament-have been well studied in the phenotypic literature, but adding a behavioral genetic perspective can enrich our understanding of temperament. We review recent behavioral genetic research in each of these areas and discuss its implications.

Externalizing Disorders and Environmental Risk: Mechanisms of Gene-Environment Interplay and Strategies for Intervention.

Though heritable, externalizing disorders have a number of robust associations with several environmental risk factors, including family, school, and peer contexts. To account for these associations, we integrate a behavioral genetic perspective with principles of a developmental cascade theory of antisocial behavior. The major environmental contexts associated with child externalizing problems are reviewed, as are the processes of gene-environment interplay underlying these associations. Throughout, we discuss implications for prevention and intervention. Three major approaches designed to reduce child externalizing behavior are reviewed. Prevention and intervention programs appear to be most successful when they target individuals or communities most at risk for developing externalizing disorders, rather than applied universally. We end by commenting on areas in need of additional research concerning environmental influences on persistent externalizing behaviors.

The adolescent origins of substance use disorders: a behavioral genetic perspective.

Over the past 20 years, there has been an increasing recognition within the substance abuse research field that substance use disorders (SUDs) are usefully conceptualized within a developmental framework. That is, initiation of substance use in adolescence and escalation to substance abuse in early adulthood are strongly age-graded, with the relevant behavioral risk and protective factors manifesting early in development, often prior to substance use onset. In this chapter, we review a program of research that seeks to provide a behavioral genetic perspective on the development of SUDs. The Minnesota Center for Twin and Family Research (MCTFR) undertakes longitudinal research on families including twins, adopted siblings, and non-adopted siblings spanning early adolescence through early adulthood. A total of nearly 10,000 individuals in 2,500 families have participated in MCTFR research. We review findings from the MCTFR to establish four general features of the development of SUDs informed by behavioral genetic research: (1) Both general and specific processes contribute to the aggregation of SUDs in families; (2) genetic contributions to SUD risk appear to be primarily at the general factor level, although the contribution of the general factor appears to decrease with age; (3) SUD risk is manifested before initiation of substance use in terms of elevated levels of externalizing psychopathology and personality characteristics indicative of low self-control; and (4) the genetic factors that contribute to SUD risk appear to be numerous with very small phenotypic effects, making them difficult to identify.

Twin Study of Impulsive Buying and its Overlap with Personality

This study explores the origins of individual differences in impulsive buying from a behavioral genetics perspective. It also assesses whether phenotypic associations between personality and impulsive buying tendency can be attributed to overlapping genetic factors. Data were collected via mail for 339 twin pairs. Personality traits according to a five-factor model and impulsive buying were measured. The results indicate that additive genetic, shared environmental, and nonshared environmental influences may be important for individual differences in impulsive buying. Phenotypic correlations with Impulsivity (r = .32), Neuroticism (r = .23), and Extraversion (r = .20) are largely driven by the overlapping genetic influences. Together with age and sex personality traits explain 25% of individual differences in impulsive buying tendency. These results add to our understanding of individual differences in impulsive buying and the nature of its relationship with personality.

Personality Resemblance Between Parents and Offspring: Study of Five Factors Across Four Samples and Questionnaires

The aim of this study was to compare personality resemblance in four independent Croatian samples using the same family study design, but different measures of five-factor personality traits. The family study design can provide evidence of familial aggregation of personality and of assortative mating. Father-mother correlations, father-offspring correlations, mother-offspring correlations and regressions of offspring on midparent score were computed for five broad personality domains in each sample. Father-mother correlations ranged between −.12 and .27 across different samples and questionnaires, while father-offspring correlations ranged between .04 and .34, mother-offspring correlations between −.01 and .28 and regressions of offspring on midparent scores between .05 and .35. These results are congruent with earlier findings of: (a) low assortative mating for personality, and (b) moderate familial aggregation of personality, which is lower compared to heritability estimates from earlier studies using twin design. Familial aggregation is mostly comparable in size across four different five-factor questionnaires suggesting that, from a behavior genetic perspective, conclusions on family resemblance should not differ depending on the five-factor personality questionnaire used.

The Covariation of Antisocial Behavior and Substance Use in Adolescence: A Behavioral Genetic Perspective

Multivariate genetic studies have revealed genetic correlations between antisocial behavior (ASB) and substance use (SU). However, ASB is heterogeneous, and it remains unclear whether all forms are similarly related to SU. The present study examines links between cannabis use, alcohol consumption, and aggressive and delinquent forms of ASB using a behavioral genetic approach. Participants were 1,688 adolescents (482 monozygotic twins, 852 dizygotic twins, and 354 nontwin siblings) aged 15–23 years old (M = 16.91), sampled from the community in the U.K. Multivariate model fitting revealed that the genetic components of alcohol consumption and cannabis use correlated with those of both aggression (.21 and .49, respectively) and delinquency (.35 and .69, respectively). Results suggest that both aggression and delinquency have genetic effects in common with alcohol consumption and cannabis use.

Predicting individual differences in reading comprehension: a twin study

We examined the Simple View of reading from a behavioral genetic perspective. Two aspects of word decoding (phonological decoding and word recognition), two aspects of oral language skill (listening comprehension and vocabulary), and reading comprehension were assessed in a twin sample at age 9. Using latent factor models, we found that overlap among phonological decoding, word recognition, listening comprehension, vocabulary, and reading comprehension was primarily due to genetic influences. Shared environmental influences accounted for associations among word recognition, listening comprehension, vocabulary, and reading comprehension. Independent of phonological decoding and word recognition, there was a separate genetic link between listening comprehension, vocabulary, and reading comprehension and a specific shared environmental link between vocabulary and reading comprehension. There were no residual genetic or environmental influences on reading comprehension. The findings provide evidence for a genetic basis to the "Simple View" of reading.

Whole Brain Size and General Mental Ability: A Review

We review the literature on the relation between whole brain size and general mental ability (GMA) both within and between species. Among humans, in 28 samples using brain imaging techniques, the mean brain size/GMA correlation is 0.40 (N = 1,389; p < 10−10); in 59 samples using external head size measures it is 0.20 (N = 63,405; p < 10−10). In 6 samples using the method of correlated vectors to distill g, the general factor of mental ability, the mean r is 0.63. We also describe the brain size/GMA correlations with age, socioeconomic position, sex, and ancestral population groups, which also provide information about brain–behavior relationships. Finally, we examine brain size and mental ability from an evolutionary and behavior genetic perspective.

Individual differences in executive functions are almost entirely genetic in origin.

Recent psychological and neuropsychological research suggests that executive functions--the cognitive control processes that regulate thought and action--are multifaceted and that different types of executive functions are correlated but separable. The present multivariate twin study of 3 executive functions (inhibiting dominant responses, updating working memory representations, and shifting between task sets), measured as latent variables, examined why people vary in these executive control abilities and why these abilities are correlated but separable from a behavioral genetic perspective. Results indicated that executive functions are correlated because they are influenced by a highly heritable (99%) common factor that goes beyond general intelligence or perceptual speed, and they are separable because of additional genetic influences unique to particular executive functions. This combination of general and specific genetic influences places executive functions among the most heritable psychological traits. These results highlight the potential of genetic approaches for uncovering the biological underpinnings of executive functions and suggest a need for examining multiple types of executive functions to distinguish different levels of genetic influences.

Influences on Child Eating and Weight Development from a Behavioral Genetics Perspective

Childhood obesity is a strong risk factor for associated comorbidities such as type 2 diabetes, cardiovascular disease, and orthopedic abnormalities in youth and its increasing incidents thus represents a major public health concern. The following review provides evidence for a familial association between parental and child weight status, eating behaviors, and food preferences. It further draws the link between environmental influences, such as parent feeding practices, and the development of child eating behaviors and thereby elucidates how genetic and nongenetic influences can contribute to the familial transmission of obesity. We use eating in the absence of hunger, an eating trait which refers to children's susceptibility to eating in response to the presence of palatable foods in the absence of hunger, as an example to illustrate these associations. The review concludes with an outlook on possibilities for future research efforts in the field.

The University of British Columbia Twin Project: Personality is Something and Personality Does Something

AbstractThe University of British Columbia (UBC) Twin Project is a registry of approximately 1500 pairs of reared-together twins recruited from Vancouver, British Columbia and surrounding municipalities. The focus of the project is to examine personality and its disorders from a behavioral genetic perspective. The primary measures include self-report measures of variables from the major models of personality and personality disorders. Subsamples of the study have also been surveyed on a wide range of psychiatric conditions and symptoms, including, for example, substance use, mood, anxiety, coping, posttraumatic stress disorder, schizotypy, and several measures of the environment and experience. Also surveyed are general health and basic psychological processes including cognitive ability. This broad assessment has enabled us to examine not only the structure of personality, but also its potential role in psychopathology and other psychological processes. A feature of the project is that the measures selected reflect current thinking in the field as opposed to traditional psychiatric diagnostic criteria. The UBC Twin Project has been used in a number of collaborative projects on personality and psychopathology with other worldwide twin registries. At the present time, no DNA has been collected; however the facility to collect these data is available. Collaborative projects on this and future questionnaire studies are welcome.

The University of British Columbia Twin Project: Personality is Something and Personality Does Something

The University of British Columbia (UBC) Twin Project is a registry of approximately 1500 pairs of reared-together twins recruited from Vancouver, British Columbia and surrounding municipalities. The focus of the project is to examine personality and its disorders from a behavioral genetic perspective. The primary measures include self-report measures of variables from the major models of personality and personality disorders. Subsamples of the study have also been surveyed on a wide range of psychiatric conditions and symptoms, including, for example, substance use, mood, anxiety, coping, posttraumatic stress disorder, schizotypy, and several measures of the environment and experience. Also surveyed are general health and basic psychological processes including cognitive ability. This broad assessment has enabled us to examine not only the structure of personality, but also its potential role in psychopathology and other psychological processes. A feature of the project is that the measures selected reflect current thinking in the field as opposed to traditional psychiatric diagnostic criteria. The UBC Twin Project has been used in a number of collaborative projects on personality and psychopathology with other world-wide twin registries. At the present time, no DNA has been collected; however the facility to collect these data is available. Collaborative projects on this and future questionnaire studies are welcome.

Are genetically informed designs genetically informative? Comment on McGue, Elkins, Walden, and Iacono (2005) and quantitative behavioral genetics.

M. McGue, I. Elkins, B. Walden, and W. G. Iacono presented the findings from a twin study examining the relative contributions of genetic and environmental factors to the developmental trajectories of parent-adolescent relationships. From a behavioral genetics perspective, this study is well conceptualized, is well implemented, and raises some interesting developmental questions. Yet, the classic twin methodology and heritability estimates obfuscate the dynamic gene-ecology transactions that underlie these social developmental trajectories. There is a growing divide between the findings of quantitative behavioral genetics, with its foundational estimate of a statistical genetic influence, and developmental molecular genetics. This comment provides a brief overview of this divide and its implications for the findings of McGue et al. as well as quantitative behavioral genetics more broadly.

Preschool social and cognitive behaviors: the Southern Illinois Twins.

The Southern Illinois Twins registry consists of a small group of twins from the southern Illinois area and some areas in Missouri and Kentucky, as well as siblings of twins and singletons who have been involved in the study. The current project has as its primary focus the identification of variables that predict aggressive and prosocial behaviors in preschoolers, especially to explore the etiology of individual differences in aggressive and prosocial behaviors from a behavior genetic perspective. Twins are tested yearly within months of their birthdays, from ages 1 year to 5 years. Siblings are tested at 5 years of age. At ages 1-4 years, children are tested on a cognitive battery and mother-child interactions are videotaped. At 5 years, children engage in a peer play situation in the lab. Results thus far suggest that aggression during play in the lab shows genetic influence, corroborating earlier parent rating studies.

Preschool Social and Cognitive Behaviors: The Southern Illinois Twins

The Southern Illinois Twins registry consists of a small group of twins from the southern Illinois area and some areas in Missouri and Kentucky, as well as siblings of twins and single-tons who have been involved in the study. The current project has as its primary focus the identification of variables that predict aggressive and prosocial behaviors in preschoolers, especially to explore the etiology of individual differences in aggressive and prosocial behaviors from a behavior genetic perspective. Twins are tested yearly within months of their birthdays, from ages 1 year to 5 years. Siblings are tested at 5 years of age. At ages 1–4 years, children are tested on a cognitive battery and mother–child interactions are videotaped. At 5 years, children engage in a peer play situation in the lab. Results thus far suggest that aggression during play in the lab shows genetic influence, corroborating earlier parent rating studies.

Intergenerational Transmission of Intimate Partner Violence

Because intimate violence tends to run in families, social learning theory posits that children learn to be violent through watching their parents and through being reinforced for their own aggressive behaviors. This account of intimate partner violence considers only environmental influences on familial resemblance, but familial resemblance may also be due to genetic factors. A genetically sensitive design is required to examine the extent to which genetic and environmental factors contribute to individual differences in intimate violence. This article reviews evidence for the intergenerational transmission of intimate violence and discusses why a genetically sensitive design is needed. It reviews behavioral genetic research that shows that aggression is genetically influenced and discusses how this research is pertinent to the study of intimate violence from a behavioral genetic perspective. It is urged that behavioral genetic studies of intimate violence be undertaken so that we may have a better understanding of this behavior.