Many people, at some point in their life, have been told that they will develop arthritis as they age because knuckle cracking causes arthritis. Children who have stumbled upon knuckle cracking oftentimes turn it into a habit, just to be told that they will have joint pain and suffering because of it. Arthritis is one concept that is generally scary for children, who oftentimes have a hard time stopping their new habit, which causes even more fear for the child. The claim that knuckle cracking causes arthritis has been prevalent throughout the world for many years, but how truthful is this statement?
Through some of the principles of critical thinking, this statement can be evaluated. The most important principle for this claim is principle #5, which states that extraordinary claims must have extraordinary evidence. Since this claim does not have a high replicability, meaning that it would be hard to test and get results that can be duplicated, there have not been many experiments testing it. Due to the lack of evidence suggesting that this claim is factual, the positive correlation between knuckle crackers and arthritis victims has brought up arguments and provided some backing to the claim, however the second principle of critical thinking states that correlation doesn't equal causation, so we can not say that the positive correlation between knuckle cracking and arthritis victims is enough to prove this extraordinary claim true. People with confirmation bias often times will even use this correlation as a guideline to deny, dismiss, or even distort evidence to fit their theory, that knuckle cracking causes arthritis. Due to the lack of extraordinary evidence backing the extraordinary claim, the fifth principle of critical thinking is the most useful way to evaluate the claim.
Recent studies on the cause of arthritis has given doctors reason to believe that knuckle cracking plays no role in the development of arthritis, however it can lead to ligament and tendon damage over time! Some people still stand by the extraordinary claim though; these people have belief perseverance, the tendency to stick to their idea even when evidence contradicts them.
Learn more at http://www.hopkins-arthritis.org/arthritis-news/2007/knuckle-cracking-and-arthritis.html, and http://oregon.providence.org/patients/programs/medical-group-arthritis-center/Pages/askanexpertlanding.aspx?TemplateName=Ask+an+Expert%3A+Knuckle+cracking+and+arthritis&TemplateType=AskAnExpert