Cognitive Dissonance Theory was proposed in 1957 by Leon Festinger. His theory states that cognitive dissonance is the mental stress or discomfort experienced by an individual who holds two or more contradictory beliefs, ideas or values at the same time; or, is confronted by new information that conflicts with existing believe, ideas or values. This mental stress or discomfort can be as strong as thirst or hunger. When we experience hunger or thirst, we look to relieve that stress by getting something to eat or drink. When a person experiences cognitive dissonance, they are equally as driven to reduce that dissonance and reach consonance. In addition to trying to reduce dissonance, a person may actively avoid situations and information that would likely increase dissonance.
In science, cognitive dissonance can be a strong driver to move science forward or it can be an anchor holding science back depending on how consonance is achieved. The history of science is littered with stories of both moving forward and holding back. Whether new information will move science forward or whether it will hold it back is up to the scientist who examine that information.
For example, Lord Kelvin, the famous physicist who formulated the first and second laws of thermodynamics, attempted to calculate the age of the earth using using thermodynamics, looking at heat transfer within the earth itself and from the sun to the earth. He calculated the age of the earth to be between 20 million years and 100 million years using mathematical models that he derived. Therefore, his calculations were only as good as his models which, in hindsight, turned out to not be very good. Geologists and biologists knew that the age of the earth HAD to be much older. Their observations of processes and changes indicated that a VAST amount of time had passed to create many of the creatures and landscapes they observed. As new information about heat sources within the earth came to light, Kelvin stubbornly refused to acknowledge this new information. His understanding of mathematics and thermodynamics shaped how he saw the world which in turn clouded his judgement. Check out these articles by T. H. Heaton and M. Livio for more information on Lord Kelvin's mistake.
A recent example that I heard about on NPR on my way to class one morning is a perfect example of cognitive dissonance moving science forward. Have a listen:
Here is a video by Richard Norris of the research he and his cousin, James Norris, conducted. Their paper is publish in PLOS One.
Here is a whiteboard explanation of how the rock are moving:
Paula Messina, featured in the NPR recording, had written her PhD thesis on the movement of these rocks. Her data suggested that the most likely explanation for the rocks' movement was freak wind storms that pushed the rocks on a thin film of water creating the grooves in the soft sediment. The Norris' data flew directly in the face of her thesis! At first, she admits, she couldn't believe what they were saying, she was in a state of cognitive dissonance. She needed to see for herself that large, wind-blown sheets of ice were the driving force behind the moving rocks as shown in this cellphone video captured by John Chadbourne. The rocks are moving to the left:
In the end, Dr. Messina reached consonance by accepting the new information and abandoning her old explanation. Science moved forward! Dr. Messina and other researchers working on the rocks of Racetrack Playa could have become increasingly dogmatic as new information came to light, strongly sticking to their explanation as a means to reach consonance. If that happened, those researchers would have either been marginalized or they may have put the breaks on the understanding of the rocks at Racetrack Playa.