College student intrinsic and/or extrinsic motivation and learning

How do extrinsic and intrinsic motives affect learning? We predicted that they would not be additive but rather that there would be interactive or curvilinear effects. Extrinsic and intrinsic goal orientation scales were administered to 13 classes-six psychology classes (two in Korea), three biology classes, three English classes, and one sociology class in a liberal arts college, a comprehensive university, and a community college. As predicted, students in the mid-third of the distribution in motivation for grades (extrinsic) who were high in intrinsic motivation achieved better grades than students with higher or lower extrinsic motivation. (C) 2002 Elsevier Science Inc. All rights reserved.