Cached Thoughts are ideas, attitudes, and beliefs that a person has formed on some past occasion, and hasn't re-evaluated since then. The name references the concept of a cache in computing: a component storing data that has been calculated or retrieved once, so that it is quickly available without needing to be recalculated or re-retrieved.
See also: Groupthink, Information Cascades, Status quo bias, Semantic Stopsign, Separate Magisteria, Rationalist Taboo
Cached thoughts can be useful in saving computational resources at the cost of some memory load, and also at the risk of maintaining a belief long past the point when evidence should force an update. In particular, cached thoughts can result in a lack of creative approaches to problem-solving, as cached solutions may interfere with the formation of novel ones. What is generally called common sense is more or less a collection of cached thoughts.
In modern civilization particularly, no one can think fast enough to think their own thoughts. If I’d been abandoned in the woods as an infant, raised by wolves or silent robots, I would scarcely be recognizable as human. No one can think fast enough to recapitulate the wisdom of a hunter-gatherer tribe in one lifetime, starting from scratch. As for the wisdom of a literate civilization, forget it.
But the flip side of this is that I continually see people who aspire to critical thinking, repeating back cached thoughts which were not invented by critical thinkers. – Eliezer Yudkowsky, Cached Thoughts