Abstract: We introduce to the literature on the recognition and spread of ideas the perspective that articles compete for the attention of researchers who might build upon them, in addition to the “bias against novelty” view documented in prior research. We investigate these effects by analyzing more than 5.3 million research publications from 1970 to 1999 in the life sciences. In keeping with the “competition for attention” view, we show that articles covering rarely addressed topics tend to receive more citations and have a higher chance of being a breakthrough paper. We also explore some conditions under which these effects might vary, by using decade subsamples, home versus foreign field forward citations, as well as short-, medium- and long-term time windows. Finally, we also find evidence consistent with the previously documented channel of “bias against novelty”, as well as that both mechanisms can work simultaneously.