Using data from interviews with 133 physicists and biologists working at elite research universities in the United States, we analyze narratives of outreach. We identify discipline-specific barriers to outreach and gender-specific rationales for commitment. Physicists view outreach as outside of the scientific role and a possible threat to reputation. Biologists assign greater value to outreach, but their perceptions of the public inhibit commitment. Finally, women are more likely than men to participate in outreach, a commitment that often results in peer-based informal sanctions. The study reveals how the cultural properties of disciplines, including the status of women, shape the meaning and experience of science outreach.