title: A model-fitting implementation of the DeFries-Fulker model for selected twin data.
abstract: In this research note, DeFries-Fulker (DF) regression analysis is reframed in model-fitting terms, where an individual's expected score is modeled as a function of their co-twin's proband status. This more flexible implementation of the DF model allows DZ-O twins to be incorporated in a sex-limitation model. Brief simulation results are presented along with the Mx scripts used.
authors.affiliation: Social, Genetic & Developmental Research Centre, Institute of Psychiatry, London SE5 8AF, UK. s.purcell@iop.kcl.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Purcell
authors.forename: P C
authors.initials: PC
authors.lastname: Sham
mesh_terms: D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D015233:Models, Statistical; D012727:Sex Characteristics; D014427:Twins; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics