How does learning about scientists' struggles during their scientific knowledge building affect students' science learning? Two hundred and seventy-one high school students were randomly assigned to 1 of 3 conditions: (a) the struggle-oriented background information (n = 90) condition, which presented students with stories about 3 scientists' struggles in creating the content knowledge that the students were learning through online physics instructional units; (b) the achievement-oriented background information (n = 88) condition, in which students learned about these 3 scientists' lifetime achievements; and (c) a no background information (n = 93) condition, a control group in which students mainly learned information about the physics contents they were studying. Our measures assessed perceptions of scientists, interest in physics lessons, recall of science concepts, and physics problem solving. We found that the achievement-oriented background information had negative effects on students' perceptions of scientists, producing no effects on students' interest in physics lessons, recall of science concepts, or their solving of both textbook-based and complex problems. In contrast, the struggle-oriented background information helped students create perceptions of scientists as hardworking individuals who struggled to make scientific progress. In addition, it also increased students' interest in science, increased their delayed recall of the key science concepts, and improved their abilities to solve complex problems. The important message that learning about scientists' struggles sends is that even great scientists work hard. Providing an opportunity for students to relate scientists to their knowledge-building activities has important implications for science learning and instruction. (Contains 4 tables.)