Peer review is a valuable guard against faulty research contaminating the literature (the body of published studies) on which all scientists rely. However, because scientists are human, personal biases and politics can sometimes creep into the review process. Fortunately, just as individual scientists strive to remain objective in conducting their research, the scientific community does its best to ensure fair review of all work.
Note that scientists are not paid money for peer review; their services are entirely voluntary. Moreover, researchers generally have to pay the journals that publish their papers. Scientists frequently present their work at professional conferences, where they interact with colleagues and receive comments on their research. Such interactions can help improve a researcher’s work and foster collaboration among researchers, thus enhancing the overall quality and impact of science. To fund their research, most scientists need to spend a great deal of time requesting money from private foundations or from government agencies such as the National Science Foundation. Grant applications undergo peer review just as scientific papers do, and competition for funding is generally intense.
Scientists’ reliance on funding sources can occasionally lead to conflicts of interest. A researcher who obtains data showing his or her funding source in an unfavorable light may be reluctant to publish the results for fear of losing funding—or, worse yet, could be tempted to doctor the results.