The issue of the conservatism of scientific research questions the nature and the role of the internal and external forces controlling the emergence of new research questions or problems, the exploration of risky directions of research, or the use of risky research methods. This issue has recently gained a new framing in connection with the growing importance of the peer-review process and of the social and economic pressures weighing on the funding of scientific research. Current literature then interrogates the external (...) and internal features that promote what are described as conservative tendencies in scientific research. In this paper, I propose to contribute to this debate by clarifying what might be internal sources of conservatism in science; that is, that are inherent to the research process itself. I distinguish two possible understandings of the sources and manifestations of this internal conservatism. I first present a representational description of the nature and origin of conservatism in science, which brings to the fore the difficulties researchers find in setting aside their conceptual framework. I then offer for consideration a larger perspective on conservatism by arguing for the existence of a practical conservatism generated by all the dimensions of scientific activities. In this framework, conservatism in science can be explained by the tendency of all practices to close in on their own local objectives. I illustrate this view by reference to an historical episode: the discovery of the chemical nature of genes by Avery. (shrink)