Irrationality enters science when people either operate the scientific method or are its subjects. Scientists are not immune to pressures, biases and subjectivity. Despite humor to the contrary, they are human. Moreover, people as subjects of experiments are so different that any one individual could respond quite differently from an experimental group. Finally, money greatly influences “objectivity.”
The editorial “How Science Goes Wrong” and the article “Trouble at the Lab” (both: The Economist, October 19, 2013 edition) detail influences calling science’s objectivity into question. This does not mean science is not important to us, but it’s also not gospel. It requires vetting even when it works well.
For example, scientists suffer even simple biases associated with names. Common names are more likely to receive research grants than unusual ones. As another one, peer review occurs when other scientists rerun experiments to verify results of the experiment’s originators. However, time, money and recognition work against this. There is not enough of the first two and little of the third in publications which tend to prefer hot, interesting topics to boost sales. Consequently, many findings never go through this important self-regulating tool. Scientists might not be any better at self-regulation than bankers are.
On the other side, when people are subjects, headline-making findings could be the result of an unusual mix of people. Even if peers achieve similar findings, there is no guarantee any one individual will respond similarly. Pharmaceutical examples are good here. Even if clinical trials show a particular outcome, dosages must still be adjusted to ensure severe, adverse reactions don’t occur in patients sensitive to the drug. Social sciences, where it’s difficult to enforce controls, offer other examples.
What irrationalities influence people? You also found ones that influence scientists.