Recently, an article in Nature addressed bias in research.
Joel Kontinen
Bias in research seems to be an increasingly serious problem. As scientists are humans, they tend to think about things in certain ways and often see what they expect to see.
They might for instance believe that the number of bees is declining and that is what they report although the reality might tell a very different story.
When it comes to topics related to worldviews, the risk of seeing imaginary ape-men or feathered dinosaurs is a real problem that, unfortunately, Nature does not mention among the areas in which research bias occurs.
Source:
Boyd, Ian. 2013. A standard for policy-relevant science. Nature 501 (7466), 159-160.