AbstractThis paper describes a general genetic model which encompasses both autosomal and X‐linked inheritance as submodels. It allows one to test for X‐linked inheritance of a trait by comparing the likelihood of X‐linked inheritance to the likelihood of the general genetic model. The general model is formulated as two loci, the first representing the trait locus and the second representing the sex chromosomes. The test for X‐linked inheritance is a test of linkage between the two loci. Three data sets were analyzed using this approach. Each was also analyzed using a variant of a model introduced by Demenais and Elston [1981], which treats the transmission probabilities as estimable parameters. Similar conclusions were reached using eithe