WK 6 Discussion: heory guides the development of specific therapeutic modalities. To understand a therapy, it may be helpful to first review the historical forces of psychology. The first force was psychoanalysis, the second force was behaviorism, the third force was humanism, and the fourth force was multiculturalism. Drawing from this progression, the first wave of behavior theory argued that all behaviors are learned and if one wants to modify behaviors, then one can unlearn them. This led to behavioral therapy based on rewards and punishment, which is considered the first wave of behavioral therapy. Since then, cognitive theory was introduced, arguing that it is crucial to factor individuals’ mental states and cognitions. Over the years, Aaron Beck’s cognitive behavior therapy, Albert Ellis’s rational emotive theory, and William Glasser’s choice theory have become prominent, falling into the second wave of cognitive therapy. Finally, the third wave of behavioral therapies include dialectical behavioral therapy, mindfulness-based cognitive behavior therapy, and acceptance and commitment therapy.