Incubation Through Selective Forgetting

Definition

When stuck on an insight problem (one requiring a shift in perspective), stepping away doesn't waste time—it enables a form of learning called incubation. The mechanism is selective forgetting: misleading clues and false approaches temporarily lose their grip on memory during the break, allowing the retrieval block they created to wear off. This doesn't mean the brain is working on the problem unconsciously in a mystical way; it means forgetting has reduced interference enough that new mental representations can surface. The brain doesn't forget the material; it forgets the fixating wrong answer, creating mental space for alternative approaches.

In the Book

Smith and Blankenship's Remote Associates Test (RAT) study illustrates this precisely. When given word puzzles with deliberately misleading hints (bad clues), subjects solved only 2 problems in 10 minutes. Given a 5-minute break where they read a science fiction story, they then solved about twice as many of the unsolved puzzles. The reading break worked only for those who had bad clues—the unfixed group showed no incubation benefit. The authors attributed this to selective forgetting: the misleading words temporarily blocked correct answers, but during the break, that retrieval block weakened. Carey connects this to everyday experience: we get unclear directions, circle back repeatedly, sit down for a few minutes, and suddenly realize we were looking in the wrong place. Romantic infatuation works similarly—time loosens the grip of fixation and we see exasperating flaws we couldn't perceive before.

Why It Matters

This concept validates rest, breaks, and even seeming procrastination as legitimate parts of problem-solving, not failures. It explains why brilliant insights often come in the shower or while doing something else, and why pushing harder on a stuck problem doesn't always help. For creative work and complex problem-solving, it suggests that the solution isn't always to spend more focused time—sometimes the best thing is to walk away and let selective forgetting do its work.