title: Multivariate extensions of a biometrical model of twin data.
mesh_terms: D000704:Analysis of Variance; D001076:Aptitude; D001699:Biometry; D005260:Female; D014644:Genetic Variation; D005823:Genetics; D005828:Genetics, Population; D006801:Humans; D007360:Intelligence; D010551:Personality; D010641:Phenotype; D011247:Pregnancy; D012107:Research Design; D012931:Social Environment; D014427:Twins