Psychologists take opposing views of how external rewards, from warm praise to cold cash, affect motivation and creativity. Behaviorists, who study the relation between actions and their consequences, argue that rewards can improve performance at work and school. Cognitive(认识派的)researchers, who study various aspects of mental life, maintain that rewards often destroy creativity by encouraging dependence on approval and gifts from others. The latter view has gained many supporters, especially among educators. But the careful use of small monetary(金钱的)rewards sparks creativity in grade-school children, suggesting that properly presented inducements(刺激)indeed aid inventiveness, according to a study in the June Journal of Personality and Social Psychology. 'If kids know they're working for a reward and can focus on a relatively challenging task, they show the most creativity,' says Robert Eisenhower of the University of Delaware in Newark. 'But it's easy to kill creativity by giving rewards for poor performance of or creating too much anticipation for rewards. ' A teacher who continually draws attention to rewards or who hands out high grades for ordinary achievement ends up with uninspired students, Eisenhower holds. As an example of the latter point, he notes growing efforts at major universities to tighten grading standards and restore failing grades. In earlier grades, the use of so-called taken economies, in which students handle challenging problems and receive performance-based points toward valued rewards, shows promise in raising effort and creativity, the Delaware psychologist claims. Psychologists are divided with regard to their attitudes toward ______ .