For the last 35 years, behaviorally oriented clinicians have adapted principles of behavior therapy to the problems of couples. They have carefully assessed couples and documented the success of their therapeutic interventions. As a result, there is a large body of evidence on the effectiveness of behavioral couples therapy (BCT). Dozens of randomized clinical trials have shown that BCT is better than no treatment or placebo treatment. These studies are summarized in major reviews (Baucom et al. 1998; Christensen and Heavey 1999; Snyder et al. 2006) and meta-analytic studies (Baucom et al. 2003; Shadish and Baldwin 2005). In the most recent of these meta-analytic studies, Shadish and Baldwin (2005) concluded that BCT "might be viewed as a mature therapy, with relatively fewer questions left to research compared with these newer therapies" (p. 11).