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Simultaneous Genetic Analysis of Longitudinal Means and Covariance Structure Using the Simplex Model: Application to Repeatedly Measured Weight in a Sample of 164 Female Twins

Published online by Cambridge University Press:  01 August 2014

S. Fischbein*
Affiliation:
Department of Educational Research, Institute of Education, Stockholm, Sweden
P.C.M. Molenaar
Affiliation:
Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands
D.I. Boomsma
Affiliation:
Department of Psychology, Free University, Amsterdam, The Netherlands
*
Department of Educational Research, Institute of Education, Box 34103, S-100 26 Stockholm, Sweden

Abstract

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The simultaneous analysis of means and covariance structures is applied to longitudinal twin data. Body weight was measured on six occasions in a sample of young female MZ and DZ twins. When average body weight at the first measurement occasion, as well as the increments in weight at later occasions, are specified in the genetic part of the model that also adequately explains the covariance structure, a good fit is obtained. In this application the increase in body weight at each occasion is weighted by the square root of the genetic variance innovation terms that represent the new genetic variance entering into the process.

Type
Research Article
Copyright
Copyright © The International Society for Twin Studies 1990

References

REFERENCES

1.Boomsma, DI, Molenaar, PCM (1987): The genetic analysis of repeated measures I: Simplex models. Behav Genet 17:111123.CrossRefGoogle ScholarPubMed
2.Dolan, CV, Molenaar, PCM, Boomsma, DI (1989): LISREL analysis of twin data with structured means. Behav Genet 19:5162.Google Scholar
3.Eaves, LJ, Long, J, Heath, AC (1986): A theory of developmental change in quantitative phenotypes applied to cognitive development. Behav Genet 16:143162.Google Scholar
4.Fischbein, S (1977): Intra-pair similarity in physical growth of monozygotic and of dizygotic twins during puberty. Ann Hum Biol 4:417430.CrossRefGoogle ScholarPubMed
5.Jöreskog, KG (1970): Estimation and testing of simplex models. Br J Math Stat Psychol 23:121145.CrossRefGoogle Scholar
6.Martin, NG, Eaves, LJ (1977): The genetical analysis of covariance structure. Heredity 38:7995.CrossRefGoogle ScholarPubMed
7.Mather, K, Jinks, JL (1977): Introduction to Biometrical Genetics. New York: Cornell University Press.CrossRefGoogle Scholar
8.Sörbom, D (1974): A general method for studying differences in factor means and factor structures between groups. Br J Math Stat Psychol 27:229239.Google Scholar
9.Sörbom, D (1976): A statistical model for the measurement of change in true scores. In de Gruijter, DNM, vanderKamp, JLTh (eds): Advances in Pyschological and Educational Measurement. New York: Wiley, pp 159169.Google Scholar
10.Sörbom, D (1978): An alternative to the methodology for analysis of covariance. Psychometrika, 43:381396.CrossRefGoogle Scholar
11.Sörbom, D (1981): Structural equation models with structured means. In Joreskog, KG, Wold, H (eds): Systems under Indirect Observation: Causality, Structure and Prediction. Amsterdam: North-Holland Publishing Co.Google Scholar