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Biomedical subjects

R Plomin

Publications and source records attributed to R Plomin.

At least 181 records · Page 10Linked to original sources
PubMed1981

Hyperactivity and pediatrician diagnoses, parental ratings, specific cognitive abilities, and laboratory measures.

Children diagnosed as hyperactive and treated for hyperactivity by private pediatricians were compared to a large unselected sample of children on parental ratings of behavioral problems (Conners Symptoms Rating Questionnaire), laboratory measures (a week-long assessment of locomotion as measured by pedometers, sustained attention, selective attention, fidgeting, and aggressiveness), and 10 tests of specific cognitive abilities (verbal reasoning, spatial reasoning, memory, and perceptual speed). Test-retest reliability was obtained for all measures. The results indicated that pediatrician diagnoses of hyperactivity are related to parental ratings but not to laboratory assessments. Diagnoses by private pediatricians may include more heterogeneous and nonspecific behavioral problems than diagnoses made in most research contexts. Pediatrician diagnoses were related to deficits in specific cognitive abilities, most notably perceptual speed and verbal ability. Hyperactivity as diagnosed by private pediatricians may reflect deficits in skills necessary to pace oneself appropriately in school-related tasks. In general, these results suggest that the criteria and methods used to diagnose hyperactivity deserve greater attention.

Aptitude Tests↗
PubMed1980

A twin study of specific behavioral problems of socialization as viewed by parents.

Our study focused on the etilogy of specific behavioral problems rather than on a global syndrome such as hyerpactivity. As a first step in studying specific behavioral problems, we revised the Conners (1970) Parent Symptom Rating questionnaire to improve its factor structure. Our revised instrument and the test-retest reliabilities of its 12 scales are described. A classical twin analysis comparing intraclass correlations for 54 pairs of identical twins and 33 pairs of same-sex fraternal twins indicated substantial genetic influence on behavioral problems in school-aged children.

Child↗
PubMed1980

An analysis of Koch's (1966) Primary Mental Abilities Test data for 5- to 7-year-old twins.

The purpose of this note is to present twin correlations based on analyses of Koch's (1966) Primary Mental Abilities Test data on 83 pairs of 5- to 7-year-old twins. The results yielded significant heritability for the Spatial subtest and suggested genetic influence on the Verbal and Quantitative subtests as well. An analysis of the phenotypic correlation between the Verbal and Spatial subtests suggested that verbal and spatial abilities are genetically independent at this age and that the relationship between the two abilities is mediated primarily by within-family environmental factors.

Child↗
PubMed1980

Specific cognitive abilities in 5- to 12-year-old twins.

Eleven tests of specific cognitive abilities were administered to 108 pairs of young twins (average age of 7.6 years). Internal consistencies are high for all measures except Raven's Coloured Progressive Matrices and Delayed Picture Memory. Two-month, test-retest reliabilities are also reported. The twin sample is representative in terms of both means and variances when compared to normative data from standardization samples, and twin correlations for height and weight are similar to those obtained in six other twin studies. Because all measures were highly correlated with age (average correlation with age was 0.64), scores were aged adjusted. Previous twin studies of specific cognitive abilities in adolescents and adults found genetic variance for nearly all tests. In contrast, our study of young twins yielded significant genetic influence for only 1 of the 11 measures, PIAT Reading Recognition, and suggested the possibility of genetic influence on 2 others (vocabulary and WISC-R mazes). Environmental influences seem to dominate, particularly for nonverbal measures, as children begin their education. In accord with other studies, we found that between-family environmental factors have an important influence on the development of nearly all of the measures of specific cognitive abilities. However, we found that our tests of perceptual speed and memory were substantially influenced by within-family environmental factors independent of error.

Child↗
PubMed1979

Multivariate behavioral genetic analysis of twin data on scholastic abilities.

Multivariate behavioral genetic analyses may employ either genetic and environmental correlations or phenotypically standardized covariances to assess the structure of genetic and environmental influences. Correlations and phenotypically standardized covariances answer different questions--correlations are appropriate for understanding the nature of genetic and environmental influences, whereas covariances are appropriate for determining the etiology of phenotypic correlations. The ratio of the genetic and environmental covariances to the phenotypic correlation yields estimates of bivariate heritability and environmentality, measures of the extent to which observed phenotypic covariance is due to genetic and environmental influences. Multivariate analyses of genetic and environmental correlations and covariances are illustrated with twin data on scholastic abilities. Factor analyses of correlations suggest that the same set of genes affects the major areas of academic achievement and that the environmental influences are similarly structured. Analyses of phenotypically standardized covariances indicate that the structures of genetic and environmental influences as they contribute to phenotypic resemblance among scholastic abilities are both similar and simple: there are one general genetic factor and one general environmental factor. Bivariate heritabilities and environmentalities are similar in magnitude, indicating that the strong phenotypic relationship among scholastic abilities is due roughly equally o genetic and environmental influences.

Analysis of Variance↗
PubMed1979

A multivariate twin analysis of within-family environmental influences in infants' social responsiveness.

Observational measures of social responsiveness were obtained for twin infants. The structure of within-family environmental influences was assessed by correlating identical twin pair differences for 13 behaviors in seven social settings. Factor analysis of the difference score matrix yielded one interpretable factor. This factor indicated that within-family environmental influences were not completely random but may exert a systematic effect on social behavior in several situations.

Child, Preschool↗
PubMed1977

Assortative mating by unwed biological parents of adopted children.

Analyses of data obtained from 662 unwed couples whose children were relinquished for adoption reveal that biological parents of adopted children mate assortatively. For physical characters, assortative mating of unwed parents was similar to that of wed parents; for behavior characters, however, there was less assortative mating by the unwed parents. Because assortative mating inflates estimates of genetic parameters in adoption studies, future studies should collect information on both biological parents.

Adoption↗
PubMed1977

A twin study of temperament in young children.

Temperament was assessed in 182 young children (91 pairs of twins, average age of 3.6 years) with use of the Colorado Childhood Temperament Inventory (CCTI). The CCTI represents a merger of dimensions suggested by two approaches to the study of the development of temperament: the New York Longitudinal Study and Buss and Plomin's temperament theory. Of the six traits measured by the CCTI, genetic factors were implicated in the etiology of five (sociability, emotionality, activity, attention span-persistence, and soothability). One trait, reaction to food, showed no genetic influence and indicated strong between-family environmental effects. A negative correlation between emotionality and soothability may also have a genetic basis. These results suggest that the development of certain personality traits--those that we include as temperament--are substantially influenced by heredity.

Attention↗
PubMed1977

Temperament in early childhood.

The structure of temperament proposed by the New York Longitudinal Study (NYLS) of Thomas and collaborators (1963, 1968) was compared to Buss and Plomin's (1975) EASI temperament theory. An objective inventory was developed for the NYLS temperaments. Mothers rated 182 children on both NYLS and EASI temperaments. Only two of the nine NYLS dimensions, attention span-persistence and distractibility, were supported by factor analysis. The four EASI dimensions (emotionality, activity, sociability, and impulsivity) were replicated. A similar sociability factor emerged from both the NYLS and EASI systems, but other temperaments were unique. The NYLS and EASI systems were merged to form the Colorado Childhood Temperament Inventory, a parental rating instrument for children 1-6 years of age.

Attention↗