Lisabeth F. DiLalla

Genetic etiology of behavioral inhibition among 2-year-old children☆

Abstract Inhibited behavior in 157, 24-month-old twin pairs was studied in a situation in which two pairs of twins, unfamiliar with each other, played together in an unfamiliar room. An intraclass correlation comparison between monozygotic (MZ) and dizygotic (DZ) twins showed that the heritability for inhibited behavior, for the entire sample, was significantly different from zero: r MZ = .82, r DZ = .47. The genetic influence on extreme inhibition was assessed using a relatively new technique which employs a multiple-regression model to predict the co-twins inhibition score from the probands score and the degree of genetic relationship (1.0 for MZ twins and 0.5 for DZ twins). The partial regression of co-twins score on relationship, an index of the extent to which the deviant scores of probands are due to heritable influences, was large and statistically significant. This result provides evidence favoring a genetic contribution to behavioral inhibition in children.

Behavior genetics of aggression in children: Review and future directions

Abstract A thorough understanding of factors that influence aggression in children cannot be achieved without including behavior genetic studies that allow us to examine the effects of shared versus non-shared environment, as well as genes, on aggressive behaviors. This review details the growing body of evidence on the genetic effects on aggression. The majority of twin and adoption studies on antisocial behavior in children suggest that genetic effects are important influences, but most of these studies utilize parent reports rather than observational data. Some recent studies of non-parent raters are beginning to suggest that aggression in childhood may indeed be heritable and that this may not be a function simply of parent reporting bias. Future studies will need to focus on gene–environment correlations and interactions to begin to disentangle the myriad ways that children and the people in their environments inter-relate and mutually affect each other.

Effect of Gender, Age, and Relevant Course Work on Attitudes Toward Empathy, Patient Spirituality, and Physician Wellness

Background: The emphasis in medical education on viewing the patient as a whole person addresses current concerns about the negative impact of standard physician training that may lead to impaired patient-physician relationships. Purposes: To assess self-ratings of empathy, spirituality, wellness, and tolerance in a sample of medical students and practitioners to explore differences by gender, age, and training. Methods: A survey was created that assesses empathy, spirituality, wellness, and tolerance in the medical setting. Surveys were completed anonymously by medical students and practitioners from the medical school. Results: The youngest groups scored highest on empathy and wellness and lowest on tolerance. Participation in medical school wellness sessions correlated with higher empathy and wellness scores; participation in both empathy and spirituality sessions correlated with higher empathy scores. Conclusion: Exposure to educational activities in empathy, philosophical values and meaning, and wellness during medical school may increase empathy and wellness in medical practice.

Effects of Environmental Measures on Intelligence in Young Children: Growth Curve Modeling of Longitudinal Data

Effects of different environmental measures on individual intellectual growth patterns were examined in 105 young children participating in a longitudinal study. Intelligence (Stanford-Binet, 4th edition) was measured at ages 3 through 6 years, and childs environment (HOME and SES) was assessed at age 3 years. Growth curve analyses revealed that HOME scores exerted a constant influence on the expected composite, verbal, and nonverbal intellectual skills at each age. Only SES influenced the rate of growth, specifically nonverbal intellectual skills. The magnitudes of these effects were moderate, but consistent, regardless of whether age-standardized or subscale raw scores were analyzed. These findings confirm that HOME and SES scores are more than just different types of measures of the childs environment.

Longitudinal Associations Among Peer Victimization and Physical and Mental Health Problems

OBJECTIVE This study examined how chronic experiences of peer victimization throughout childhood relate to mental and physical health outcomes in adolescence. METHODS Children were tested in a laboratory playroom at the age of 5 years. They completed questionnaires at time 2, between the ages of 10 and 18 years, and a telephone interview at time 3, between the ages of 12 and 20 years. A total of 70 youth participated at all three time periods. Chronic victims were defined as having high levels of peer victimization at all three time points. RESULTS Youth who were chronically victimized reported experiencing significantly more mental and physical health problems than youth categorized as desisters or nonvictims. Also, for girls only, chronic victims reported more specific health problems (headaches, sleep problems) than did nonchronic victims. CONCLUSIONS The present findings may assist health professionals in assessing and treating physical and mental health problems that appear to be related to peer victimization.

Prevalence of Health-Related Behaviors Among Physicians and Medical Trainees

ObjectiveThe authors studied the prevalence of health-promoting and health-risking behaviors among physicians and physicians-in-training. Given the significant potential for negative outcomes to physicians’ own health as well as the health and safety of their patients, examination of the natural history of this acculturation process about physician self-care and wellness is critical to the improvement of the western health care delivery system.Methods963 matriculating medical students, residents, or attending physicians completed the Empathy, Spirituality, and Wellness in Medicine (ESWIM) survey between the years 2000 and 2004. Items specific to physician wellness were analyzed. These included healthy behaviors as well as risk behaviors.ResultsBoth medical students and attending physicians scored higher in overall wellness than did residents. Residents were the lowest scoring group for getting enough sleep, using seatbelts, and exercising. Medical students were more likely to smoke tobacco and drink alcohol. Medical students reported less depression and anxiety and more social contacts.ConclusionMedical school training may prevent students from maintaining healthy behaviors, so that by the time they are residents they exercise less sleep less and spend less time in organizational activities outside of medical school. If physicians do not engage in these healthy behaviors, they are less likely to encourage such behaviors in their patients and patients are less likely to listen to them even if they do talk about it.

Genetic and gene–environment interaction effects on preschoolers' social behaviors

This study examined effects from a specific dopamine receptor gene (DRD4), environmental influences from parents and peers, and the interaction between them, on aggressive and prosocial behaviors of preschoolers. Children were classified as DRD4-L (n = 27) if they had at least one DRD4 allele with six to eight repeats and as DRD4-S (n = 35) if not. Parent-child interactions were coded when children were 3-4 years old. Peer interaction data and parent questionnaires were collected at age 5. DRD4-L children shared less with each other and parents were less sensitive during parent-twin triadic interactions. Also, genotype interacted with peer aggression to affect childrens aggression during a peer play interaction at age 5, and genotype interacted with prior parental sensitivity to affect later externalizing problems. Thus, children having a certain genetic disposition may be more sensitive to certain environmental stimuli and therefore more likely to exhibit aggressive behaviors under more stressful circumstances.

Differential maternal treatment of infant twins: Effects on infant behaviors

This project utilized twins to study differential mother-sibling interactions. The use of twins circumvented the traditional confounds of studying siblings of different ages or at two points in time. When the twins were 7 and 9 months of age, mothers spent 2.5 min alone with each infant in an attempt to elicit child vocalizations. The mother and infant behaviors were coded both microanalytically and globally. The infant attention behaviors were influenced primarily by unique environment, whereas the temperament behaviors were influenced by both unique environmental and genetic effects. Mothers tended to treat both children similarly, regardless of zygosity, suggesting that maternal characteristics drove the mother-infant interactions. Thus, even though identical twins were more similar on some measures than fraternal twins, mothers tended to treat both types of twins comparably regardless of infant characteristics or behaviors.

Emotional Faces Capture Spatial Attention in 5-Year-Old Children

Emotional facial expressions are important social cues that convey salient affective information. Infants, younger children, and adults all appear to orient spatial attention to emotional faces with a particularly strong bias to fearful faces. Yet in young children it is unclear whether or not both happy and fearful faces extract attention. Given that the processing of emotional faces is believed by some to serve an evolutionarily adaptive purpose, attentional biases to both fearful and happy expressions would be expected in younger children. However, the extent to which this ability is present in young children and whether or not this ability is genetically mediated is untested. Therefore, the aims of the current study were to assess the spatial-attentional properties of emotional faces in young children, with a preliminary test of whether this effect was influenced by genetics. Five-year-old twin pairs performed a dot-probe task. The results suggest that children preferentially direct spatial attention to emotional faces, particularly right visual field faces. The results provide support for the notion that the direction of spatial attention to emotional faces serves an evolutionarily adaptive function and may be mediated by genetic mechanisms.

The southern Illinois twins and siblings study (SITSS): Description and update

This update on the Southern Illinois Twins and Siblings Study (SITSS) documents some of the follow-up studies that have been conducted and results that have been obtained from this sample. At the current time, 283 twin pairs, 8 triplet families, 98 non-twin sibling pairs, and 287 singletons have been enrolled in SITSS. Twins and triplets are tested as young as 1 year of age and then every year on their birthday through age 5 years. A variety of follow-up studies have been conducted for SITSS children through age 20. Results thus far have demonstrated significant genetic influences on social behaviors such as aggression, victimization, and attention toward facial expressions. Interesting interactions have been documented between the dopamine receptor D4 gene (DRD4) and the social environment (parental sensitivity or peer aggression) as they predict childrens aggressive behaviors. In addition, increased difficulty with social interactions has been noted for twins versus singletons. Thus, this multi-trait, multi-method behavior genetic data set contributes to our understanding of the etiology of social behaviors in preschoolers and to predictors of similar behaviors through adolescence.