根据下面资料，回答题
Psychologists take contrastive views of how external rewards, from ( 31 ) __ praise to cold cash, affect motivation and creativity. Behaviorists, (32)  research the relation (33) __ actions and their conse- quences argue that rewards can improve performance at work and school. Cognitive researchers, who study various aspects of mental life, maintain (34) __ rewards Often destroy creativity (35)   ________  encouraging depend- ence (36)_ approval and gifts from others.
The latter view has gained many supporters, especially (37)educators. But the careful use of small monetary rewards sparks (38) __ in grade-school children, suggesting (39)properly presented in- ducements indeed aid inventiveness, (40)to a study in the June Journal of Personality and Social Psychol- ogy.
"If kids know they're working for a (41)__ and can focus (42) __ a relatively challenging task, they show the most creativity", says Robert Eisenberger of the University of Delaware in Newark. "But it's easy to kill creativity by giving rewards for (43) __ performance or creating too (44)_ anticipation for re- ward,s. "
A teacher (45) __ continually draws attention to rewards or who hands (46)_ high grades for ordinary achievement ends up (47) discouraged students, Eisenberger holds. (48) an example of the latter point, he notes growing efforts at major universities to tighten grading standards and restore failing (49)
In earlier grades, the use of so-called token economies, in (50) students handle challenging problems and receive performance-based points toward valued rewards, shows promise in raising effort and creativity, the Del- aware psychologist claims.
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