title: A model for sibling effects in man.
abstract: A model is developed to specify the environmental effect of one sibling on another for a polygenic trait. Such effects are detectable in priniciple and the approach is illustrated with twin data relating to psychoticism. The relationship between the model and those employed in the treatment of kin selection is indicated.
mesh_terms: D005260:Female; D014644:Genetic Variation; D006801:Humans; D008954:Models, Biological; D010641:Phenotype; D011247:Pregnancy; D012801:Sibling Relations; D014427:Twins