We illustrate some of the challenges of credit allocation in science by discussing the Thomas theorem –often seen as the orgin of the “self-fulfilling prophecy” – which, ironically given its subject matter, has been repeatedly cited as the work of W. I. Thomas alone. Thomas’ coauthor and wife, Dorothy Swaine Thomas, has never received the credit she deserved for the discovery. This raises this issue of how biases affect credit allocation in science, since our perception of who deserves credit is reinforced by the Matthew effect. We tend to give disproportionate credit to renowned scientists over unknowns, making coauthoring with eminent scientists risky. Many of these problems arise because credit is allocated collectively in science, based on the community’s perception of who is responsible for a discovery. While that perception is often correct, there are plenty of instances where the community gets it wrong. We describe how a collective credit allocation algorithm, which was created using cocitation patterns, can capture how the community assigns credit and predict who will get credit for a discovery. We then discuss the algorithm’s implications for individual scientists.