Every maze can be exited eventually, including the one shown in Fig. 10.3 , which symbolizes the challenge of choosing the right methodology and data for analyzing assortative mating. A laborious but reliable strategy to find the exit is to place one’s hand on the wall to one side and follow it until reaching the way out. Using the reliable strategy, this book has guided its readers through many U-turns, by reviewing a comprehensive set of indicators, models, and methods put forward in the literature on assortative mating.