This study analyzes cultural trait transmission among a sample of 172 Western North American Indian societies. The authors use autologistic models built upon spatial and linguistic neighbor graphs to examine the importance of vertical versus horizontal trait transmission. Findings suggest that cultural trait distributions cannot be explained by the transmission of traits from parent to daughter populations and are better analyzed using phylogenies. Authors also show that vertical and horizontal transmission can be incorporated in a single model and may both act upon a single trait. Analysis of only one type of cultural transmission would result in a loss of information.