The results of unexperienced teachers' behavior study during professional adaptation are presented. It is shown that one of the basic factors destabilizing activity and provoking ineffective forms of behavior is the discrepancy between the motivation when planning activity and real motivation when realizing the plan. In subjectively complicated situations considerable part of examinees possessing domineering motives of personal self-assertion undergoes (not taken into consideration) change from pragmatically motivated activity to personally motivated one. This process is mediated by some individual motivational and emotional characteristics. Different behavior styles in complicated pedagogical situations connected to different personal peculiarities are presented.