Under certain circumstances, and with appropriate trigger mechanisms, adult learners may indulge in hostile classroom behaviors through which they resist learning, encourage others to do the same, and even engage in a direct, intentional, hostile attack upon the instructor. Hostile, deliberate, overt resistance to learning is very real, different from motivation, and rarely discussed. It is a significant problem in the field of adult learning, yet has received scant direct attention in the literature, despite its prevalence, high cost, and clear relevance to policy and practice. This paper describes the dynamic interactions among instructor and adult students in classroom learning environments, identifies the major relevant issues in play, and discusses each as potential causes of hostile resistance to learning. Learning is a process of change, and as such involves feelings of uncertainty and ambiguity, which create discomfort. Issues of power and control may arise, accompanied by power plays employed by manipulative people. Perceptual filters are used by the participants as mechanisms to interpret meaning and select appropriate responses are described. These filters vary by such factors as race, culture, gender, and life experiences. The participants react to the challenge of learning, in ways consistent with their behavioral predispositions, the degree of threat they perceive, and their personal views regarding their responsibility and ability to control their own life events. Participants' responses often include hostile, overt refusal to assimilate or even consider the learning material. The practitioner will be engaging in a dynamic assessment of the learning experience as it unfolds, gauging results so as to be able to adjust factors under the instructor's control, such as pace and style. The process does not end there, as the practitioner continuously engages in a reflective process of self-questioning concerning the progress and status of the learning activity.