ABSTRACT
In this article, the authors examined the genetic and environmental factors influencing expressive language development in a sample of 386 toddler twin pairs participating in the Wisconsin Twin Project. Expressive language was assessed using 2 measures from the MacArthur Communicative Development Inventories-Short Form: Total Vocabulary and Two-Word Combination Use (L. Fenson et al., 2000). A sex-limitation structural equation model estimated the contribution of genetics, shared environment, and nonshared environment to individual variation. For vocabulary, heritability was higher for boys than for girls (20% vs. 8%). For word combination use, heritability was higher for girls (28% vs. 10%). However, the majority of individual variation in both boys and girls could be attributed to shared environment (54%-78%).
Subject(s)
Environment , Language Development Disorders/diagnosis , Language Development Disorders/genetics , Twins, Dizygotic/genetics , Twins, Monozygotic/genetics , Verbal Behavior , Female , Humans , Infant , Language Development Disorders/epidemiology , Male , Sex Factors , Speech Production Measurement/methodsABSTRACT
Inadequate early caregiving has been associated with risks of stress-related psychological and physical illness over the life span. Dysregulated physiological stress responses may represent a mechanism linking early caregiving to health outcomes. This paper reviews evidence linking early caregiving to physiological responses that can increase vulnerability to stress-related illness. A number of high-risk family characteristics, including high conflict, divorce, abuse, and parental psychopathology, are considered in the development of stress vulnerability. Three theoretical pathways linking caregiving to physiological stress responses are outlined: genetic, psychosocial, and cognitive-affective. Exciting preliminary evidence suggests that early caregiving can impact long-term physiological stress responses. Directions for future research in this area are suggested.
Subject(s)
Caregivers/psychology , Stress, Psychological , Adolescent , Adult , Age Factors , Aged , Child , Conflict, Psychological , Divorce/psychology , Family Relations , Female , Health Status , Humans , Hydrocortisone/blood , Life Change Events , Male , Middle Aged , Parent-Child Relations , Risk FactorsABSTRACT
This study examined the hypothesis that item overlap, or measurement confounding, accounts for the correlation between temperament and behavior problem symptoms in children. First, a conceptual approach was taken in which 41 experts rated temperament (Children's Behavior Questionnaire, CBQ) and behavior problem symptom items (Preschool Behavior Questionnaire, PBQ) for their fit to both constructs. With this approach, 10% of temperament and 38% of symptom items were confounded. Second, an empirical approach was taken and CBQ and PBQ items were factor analyzed with data from a multi-informant longitudinal study of 451 children. Using this method, 9% of temperament and 23% of symptom items were confounded. Most importantly, removing the confounded items from the CBQ and PBQ scales did not affect the relation between temperament and symptoms, suggesting that the associations were not due to measurement confounding. In addition, the predictive power of earlier temperament for DSM-IV symptoms (Health and Behavior Questionnaire) remained high with the purified CBQ scale. The findings of this study contribute to the understanding of the relation between normal-range temperament and extreme behavior.
Subject(s)
Child Behavior Disorders/diagnosis , Child Behavior Disorders/epidemiology , Temperament , Child , Female , Follow-Up Studies , Humans , Male , Surveys and QuestionnairesABSTRACT
The Wisconsin Twin Panel was initiated in 1994 to serve a study of the development of childhood mood and behavioral disorders. Families who give birth to twins within the state of Wisconsin are recruited within 6 months of the birth. The panel currently supports three ongoing, longitudinal research projects. Research foci include studying epigenetic contributions to emotional, physical, cognitive, and motoric development of infant and toddler twins; physiological concomitants of childhood temperament; and early risk and resiliency factors related to child psychopathology. All three studies include videotaped observational assessments and biological measures.
