NORMS OF BEHAVIOR IN SCIENTIFIC RESEARCH represent ideals to which most scientists subscribe. Our analysis of the extent of dissonance between these widely espoused ideals and scientists' perceptions of their own and others' behavior is based on survey responses from 3,247 mid- and early-career scientists who had research funding from the U.S. National Institutes of Health. We found substantial normative dissonance, particularly between espoused ideals and respondents' perceptions of other scientists' typical behavior. Also, respondents on average saw other scientists' behavior as more counternormative than normative. Scientists' views of their fields as cooperative or competitive were associated with their normative perspectives, with competitive fields showing more counternormative behavior. The high levels of normative dissonance documented here represent a persistent source of stress in science.