Parkinson's Law Of Triviality
Parkinson's Law of Triviality is an observation about how humans can so involve themselves with details and minutiae (trivial things) that they let crucial matters go unattended. This is not to be confused with Parkinson's Law, which states that a job will always expand to meet the time allotted for it. Both of these observations are attributed to Cyril Northcote Parkinson, a British Naval historian and author.
An example of the law of triviality, a cognitive bias, would be a group that gets so involved discussing the causes and minor details of a problem that they fail to develop actual solutions to the problem.