Biomedical subjects

M McGue

Publications and source records attributed to M McGue.

At least 73 records · Page 4Linked to original sources

PubMed1995

Genetic influences on memory performance in adulthood: comparison of Minnesota and Swedish twin data.

Results from 2 twin studies of aging differ concerning the heritability of memory performance in adulthood. Heritability estimates from the Minnesota Twin Study of Adult Development and Aging (MTSADA; D. Finkel & M. McGue, 1993) are larger than estimates from the Swedish data (N. L. Pedersen, R. Plomin, J. R. Nesselroade, & G. E. McClearn, 1992). Memory data were available from MTSADA on a sample of 112 monozygotic (MZ) twin pairs and 111 dizygotic (DZ) twin pairs ages 27 to 88 years and from the Swedish study on a sample of 86 MZ and 110 DZ twin pairs who were reared together and were ages 27 to 85 years. Univariate and multivariate behavior genetic analyses were conducted to determine the significance and source of differences in heritability across studies. No significant age differences were found in either study. Study differences were found at the level of specific memory measures, but not at the level of a general memory factor.

Adult↗

PubMed1995

Familial aggregation of phonological disorders: results from a 28-year follow-up.

This investigation is a follow-up to a longitudinal speech and educational outcome study involving approximately 400 normally developing children that was initiated in 1960. From this database, two groups of subjects (now aged 32-34), their spouses, and all of their offspring over the age of 3:0 (years:months) completed a battery of cognitive-linguistic and interview measures. One group (probands) consisted of 24 adults with a documented history of a moderate phonological-language disorder that persisted through at least the end of the first grade. The other group (controls) consisted of 28 adults who were known to have had normal articulation abilities as children. Results of this study demonstrated that, in comparison to the children of controls, the children of the proband subjects performed significantly more poorly on all tests of articulation and expressive language functioning and were significantly more likely to have received articulation treatment. There was, however, no evidence that specific misarticulations or phonological processes traveled within proband families. These results are in agreement with those of most previous family studies that have demonstrated an increased rate of occurrence of speech-language disorders of unknown origin in families including a first-degree relative who is similarly affected.

Achievement↗

PubMed1995

A cross-sectional examination of height, weight, and body mass index in adult twins.

A cross-sectional twin design was used to study the developmental nature of genetic and environmental influences on height, weight, and body mass index. The sample of same-sex adult male and female twins consisted of 586 monozygotic and 447 like-sex dizygotic twin pairs aged 18 to 81 years. Means and variances suggested normative age differences for all three physical variables. Biometrical model-fitting with maximum likelihood methods of parameter estimation indicated that the general best-fitting model across the age groups for height, weight, and body mass index was one in which the genetic effects were additive and the environmental effects were from nonshared, idiosyncratic experiences. The best-fitting cross-sectional biometrical model for height, weight, and body mass index indicated that additive genetic variance remained stable while nonshared environmental variance increased with age. This increase in environmental variance but stable genetic variance resulted in decreasing heritability with age for height (heritability ranging from 0.89 in the youngest group to 0.87 in the oldest), weight (heritability ranging from 0.86 in the youngest group to 0.70 in the oldest), and body mass index (heritability ranging from 0.82 in the youngest group to 0.63 in the oldest).

Adolescent↗

PubMed1995

Genetic and environmental influences on functional age: a twin study.

Twin analyses were conducted to determine the relative influence of genetic and environmental factors on functional aging. As part of the ongoing Minnesota Twin Study of Adult Development and Aging (MTSADA), measures of 30 demographic, cognitive, physiological, personality, and behavioral variables were available from 140 monozygotic twin pairs and 97 dizygotic twin pairs ranging in age from 27 to 88 years. Functional age was based on a general linear regression model with chronological age as the dependent variable. Stepwise regression determined the subset of variables by MTSADA providing the best prediction of chronological age. Factor analysis of these 12 variables resulted in three factors: physiological measures, cognitive abilities, and processing speed. When entered into, a regression equation, the three factors accounted for 66% of the variance in chronological age. Analysis of twin similarity for components of functional age suggested the relative influence of genetic and environmental factors varies greatly for different components of functional aging. In addition, the genetic and shared environmental influences on the three components were common to all three, while the nonshared environmental influences were specific to each component.

Adult↗

PubMed1994

Familial resemblance for immunoglobulin levels.

The familial resemblance for immunoglobulin A, D, E, G, and M levels was investigated with family data collected in Canada and the U.S., entertaining both multifactorial and single gene hypotheses. Significant familial effects were found for each of the immunoglobulins, and there was significant support for a major gene hypothesis for IgA and IgD levels. Whereas there have been several reports suggesting a major gene determinant for IgE levels, including that from our own Canadian study, analysis of the U.S. sample suggested that a multifactorial component parsimoniously explained the observed familial resemblance.

Analysis of Variance↗

PubMed1994

A simple algebraic demonstration of the validity of DeFries-Fulker analysis in unselected samples with multiple kinship levels.

DeFries and Fulker's (Behav. Genet. 15, 467-473, 1985) regression procedure (DF analysis) to estimate c2 and h2 was originally applied to selected twin data. Since then, DF analysis has been applied more broadly in unselected data and with multiple (nontwin) kinship levels. Theoretical work based on the matrix algebra of variance-covariance matrices has shown that estimates of c2 and h2 are unbiased in selected two-group settings. In this article, a simple proof is presented supporting the validity of DF analysis in broader settings. We use scalar algebra to show that parameter estimates of h2 and c2 are unbiased in unselected settings with multiple (more than two) kinship levels. Caveats are offered, and other DF analysis problems are identified.

Bias↗

PubMed1994

A 28-year follow-up of adults with a history of moderate phonological disorder: educational and occupational results.

The present investigation is a follow-up to a longitudinal study involving approximately 400 normally developing children begun in 1960. From this large database, two groups of subjects (now aged 32-34) were asked to participate in the present project: (a) a group of 24 adults with a documented history of a moderate phonological/language disorder that persisted through at least the end of first grade (probands), and (b) a group of 28 adults from the same birth cohort and schools who were known to have had at least average articulation skills over the same period (controls). As part of a larger project, these adults were interviewed about their educational and occupational accomplishments and those of their siblings. Results revealed that, in comparison to control subjects, the proband adults reported that they had received lower grades in high school, required more remedial academic services throughout their school careers, and completed fewer years of formal education. Occupationally, although the groups did not differ in employment status, the proband subjects tended to occupy jobs considered semiskilled or unskilled with a much greater frequency than both the control subjects and their gender-matched siblings. When asked to indicate general satisfaction with educational and occupational outcomes, however, subjects in both groups tended to rate themselves as either "very" or "fairly" satisfied.

Adult↗

PubMed1994

A longitudinal family study of personality change and stability.

The 19-year stability of personality from late adolescence to early adulthood was examined in a sample of 121 men and women who had participated in an earlier study of articulation and language development (Templin, 1966; Templin & Glaman, 1976). Personality was assessed using the Eysenck Personality Inventory (EPI). At the time of retest, personality data were also collected from the participants' mothers. Modest stability of individual differences in personality was observed, consistent with the literature on longitudinal studies of personality during late adolescence and early adulthood. For the Extraversion and Neuroticism scales, offspring means decreased significantly over the 19-year period such that the offspring means were closer to the mean scores of their mothers when they were followed up in adulthood as compared to their first testing in adolescence. There was, however, no change in mother-offspring resemblance from the initial test to retest. Mother-offspring resemblance appears to be due largely to aspects of personality that were stable from adolescence to early adulthood. Implications of these results are discussed in relation to the findings of previous longitudinal studies of adult personality and recent behavioral genetic evidence regarding personality change and stability.

Adolescent↗

PubMed1993

Sensation seeking in opposite-sex twins: an effect of prenatal hormones?

Intrauterine hormones and position with respect to male and female littermates influence sexually dimorphic adult behavior in litter-bearing animals. Opposite-sex dizygotic twins offer the opportunity to examine analogous effects on sex-related human behaviors. To illustrate this approach, Sensation Seeking Scale (SSS) scores from 422 British twin pairs, including 51 opposite-sex pairs (Zuckerman, M., et al., J. Consult. Clin. Psychol. 46:139-149, 1978), were reanalyzed. Zuckerman et al. (1978) have shown that some aspects of sensation seeking are consistently increased in males relative to females. In comparing age-adjusted data for opposite and same-sex twins, our reanalysis demonstrated the predicted increase in sensation seeking in female members of opposite-sex pairs. Results were significant for measures of disinhibition, experience seeking, and overall sensation seeking. In contrast, male opposite-sex twins were not significantly different from male same-sex twins. Although psychosocial explanations of the increased sensation seeking in opposite-sex female twins cannot be excluded, these finding are consistent with hypothesized in utero hormonal influences on later behavioral development.

Adolescent↗

PubMed1993

Age and the self-perception of ability: a twin study analysis.

Two thousand nine hundred seventy-four adults, including 678 monozygotic and 547 dizygotic twin pairs, aged 27-86 years, self-rated ability on 6 factors: Interpersonal Competence, Workplace Skills, Trade Skills, Intellectual and Cultural, Domestic Skills, and Athletic Competition. Age accounted for no more than 2% of the variance on any factor, and, although there were significant gender effects, no significant Age X Gender interactions were observed. Twin similarity did not vary significantly with age, and biometrical variance component estimates were statistically homogeneous across age with talent factor variance being apportioned approximately equally to genetic and nonshared environmental factors. Consistent failure to find age effects as well as consistent observation of significant heritability support the conclusion that self-concept crystallizes early in adulthood and reflects genetically influenced psychological characteristics.

Adult↗

PubMed1993

The origins of individual differences in memory among the elderly: a behavior genetic analysis.

The purpose of this investigation was to apply behavior genetic methods to investigate individual differences in memory performance. Memory and various cognitive and lifestyle variables were obtained from 93 monozygotic twin pairs and 67 dizygotic twin pairs aged 60-88 years as part of the Minnesota Twin Study of Adult Development and Aging. Univariate analysis, used to determine the relative influence of genetic and environmental factors on 4 measures of memory (word recall, immediate and delayed text recall, and figure memory), suggested that 55% of the variance in memory performance could be attributed to genetic factors. Bivariate analysis was used to determine the specific variables that mediate the genetic and environmental influences on memory. Results suggested that the relationship between memory and cognitive variables was genetic in nature, whereas the nature of the relationship between memory and lifestyle variables was environmental.

Aged↗

PubMed1993

Heritability of interests: a twin study.

The authors administered inventories of vocational and recreational interests and talents to 924 pairs of twins who had been reared together and to 92 pairs separated in infancy and reared apart. Factor analysis of all 291 items yielded 39 identifiable factors and 11 superfactors. The data indicated that about 50% of interests variance (about two thirds of the stable variance) was associated with genetic variation. The authors show that heritability can be conservatively estimated from the within-pair correlations of adult monozygotic twins reared together. Evidence for nonadditive genetic effects on interests may explain why heritability estimates based on family studies are so much lower. The authors propose a model in which precursor traits of aptitude and personality, in part genetically determined, guide the development of interests through the mechanisms of gene-environment correlation and interaction.

Adult↗

PubMed1993

Longevity is moderately heritable in a sample of Danish twins born 1870-1880.

The heritability of human longevity was investigated in a sample of 218 pairs of monozygotic (MZ) and 382 pairs of like-sex dizygotic (DZ) Danish twin pairs born 1870-1880. Twin similarity for age at death was significant for MZ twins but nonsignificant for DZ twins. The heritability (h2) of life span estimated from the best-fitting biometrical model was statistically significant but moderate in magnitude (h2 = .333 +/- .058). Heritability of longevity did not vary by gender, and the pattern of twin resemblance was more consistent with nonadditive as compared to additive genetic effects. In addition, evidence for a genetic association between premature and senescent deaths was observed. Although environmental factors accounted for a majority of the variance in life span, the relevant environmental factors appeared to be those that create differences rather than similarities among reared-together relatives. Findings are discussed in terms of their relevance for understanding the inheritance and evolution of human life span.

Aged↗

PubMed1992

Genetic and environmental influences on baseline SCE.

Previous population-based studies have identified subject characteristics that, when combined, can account for approximately 20% of the observed interindividual variation in baseline SCE rates. In the present investigation, a classic twin study design was used to address the issue of the relevance of genetic factors to baseline SCE rates and to identify other demographic, hematologic, and exposure variables predictive of SCE rate. Questionnaire data and peripheral blood samples from 136 monozygotic and 88 dizygotic twins (age range: 25-81 years) were obtained. Among the large number of variables examined, univariate analyses (including ANOVA tests for the categorical variables and Pearson-product moment correlations for the quantitative variables) revealed smoking status, coffee drinking status, sex, white blood cell count, and absolute numbers of lymphocytes and neutrophils to have significant effects on SCE rates. A stepwise multiple regression analysis showed that together, smoking and coffee drinking status entered at the first step accounted for 21% of the observed variance in SCE, with a further 6% being contributed by the demographic and hematologic variables added in subsequent steps. Finally, the twin analyses showed that after adjustment of the data set for smoking and other significant predictors, genetic factors accounted for approximately 30% of the variation in SCE rates. Thus these data support the hypothesis of a significant genetic influence on baseline SCE.

Environment↗

PubMed1992

Emergenesis. Genetic traits that may not run in families.

Traits that are influenced by a configuration--rather than by a simple sum--of polymorphic genes may not be seen to be genetic unless one studies monozygotic twins (who share all their genes and thus all gene configurations) because such "emergenic" traits will tend not to run in families. Personal idiosyncrasies that have been found to be surprisingly concordant among MZ twins separated in infancy and reared apart may be emergenic traits. More speculatively, important human traits like leadership, genius in its many manifestations, being an effective therapist or parent, as well as certain psychopathological syndromes may also be emergenic. These ideas reemphasize the importance of the role played in human affairs by genetic variation.

Adult↗

PubMed1992

Sex and age effects on the inheritance of alcohol problems: a twin study.

Male monozygotic cotwins of probands with Alcohol Abuse-Dependence (n = 85) were more likely than male same-sex dizygotic cotwins (n = 96) to report alcohol, drug, and conduct disorder problems. For women, rates of problem behavior did not differ between monozygotic (n = 44) and same-sex dizygotic (n = 43) cotwins. Opposite-sex dizygotic twin data (n = 88) revealed significant cross-sex transmission; alcohol problems were greatest among male cotwins of female probands. For men, proportion of liability variance associated with additive genetic factors was significantly greater when proband had an early (h2 = .73 +/- .18) rather than late (h2 = .30 +/- .26) age of onset. For women, heritability did not vary as a function of proband's age of onset, and the pooled estimate suggested little genetic influence (h2 = .00, SE not computable). Findings suggest that genetic influences may be substantial only in the etiology of early-onset male alcoholism.

Adult↗

PubMed1992

A 28-year follow-up of adults with a history of moderate phonological disorder: linguistic and personality results.

The present investigation is a follow-up to a longitudinal speech and academic study involving approximately 400 normally developing children begun in 1960 by Mildred Templin. From this large data base, the present project invited the participation of two groups of subjects (now aged 32 to 34): (a) 24 adults with a documented history of moderately severe phonological disorder that persisted at least through the end of first grade (probands) and (b) 28 adults from the same birth cohort and schools who were known to have had at least average articulation skills over the same period (controls). Results of follow-up testing revealed that the proband adults performed significantly more poorly than the control adults on all of the administered measures of articulation, expressive language, and receptive language. Results obtained from a screening of nonverbal reasoning ability were equivocal. On a questionnaire measure of personality, both groups scored well within the normal range for the dimensions of extroversion and neuroticism when compared to the test's normative sample. These results have been interpreted as suggesting that although many adults with a childhood history of delayed phonological development will continue to experience linguistic outcomes that are less favorable than those of controls, their performance in selected nonlanguage domains (e.g., nonverbal reasoning, personality) will be far more typical of the general population.

Adult↗

PubMed1992

When assessing twin concordance, use the probandwise not the pairwise rate.

Geneticists and twin researchers have long debated the relative merits of two alternative measures of twin concordance: the pairwise and probandwise concordance rates. The results of this debate are now quite clear, for almost every application the probandwise rate is preferred over the pairwise rate. In a recent review of schizophrenia twin studies, however, Torrey (1992) chose to analyze pairwise rather than probandwise rates. Torrey's use of pairwise rates led him to conclude that the monozygotic twin concordance for schizophrenia is weaker than what is widely accepted, and that, by implication, the magnitude of the genetic contribution to schizophrenia has been overestimated. In this brief commentary, we review the relative strengths and weaknesses of the pairwise and probandwise rates and show that Torrey's conclusion is based upon his incorrect use of pairwise rates. Twin studies of schizophrenia continue to support the existence of a strong genetic influence on the development of schizophrenia.

Female↗