Conflicts over proper attribution can arise in any of these places. Citations serve many purposes in a scientific paper. They acknowledge the work of other scientists, direct the reader toward additional sources of information, acknowledge conflicts with other results, and provide support for the views expressed in the paper. More broadly, citations place a paper within its scientific context, relating it to the present state of scientific knowledge. Failure to cite the work of others can give rise to more than just hard feelings.
Citations are part of the reward system of science.
They are connected to funding decisions and to the future careers of researchers. More generally, the misallocation of credit undermines the incentive system for publication. In addition, scientists who routinely fail to cite the work of others may find themselves excluded from the fellowship of their peers. This consideration is particularly important in one of the more intangible aspects of a scientific career-that of building a reputation. Published papers document a person's approach to science, which is why it is important that they be clear, verifiable, and honest.