A break helps by letting the mind drift, not by resting
Creative incubation means stepping away from a problem and coming back to it later. The most consistent finding across these studies is that the benefit comes from what the mind does during that gap. In a preregistered writing experiment, participants wrote two short stories separated by a ten-minute break filled with one of several tasks, and those who reported more mind wandering during the break showed greater improvement in the creativity of their stories, measured by semantic distance, a word-based proxy for how far a story strays from the obvious [3]. The effect held after controlling for how much people generally mind-wander in daily life, and it did not extend to deliberately thinking about the story during the break [3].
That last detail matters for the ability question. If the gain came from effortful rehearsal or from simply being smarter, then consciously working on the story during the break should have helped too. It did not. The benefit tracked spontaneous off-task thought instead, which points away from ability as the main gate and toward a cognitive style or habit that anyone might have more or less of [3].
The benefit only appeared when people returned to the same problem
The writing study added a condition that sharpens the picture: some participants got the same prompt after the break, others a new one. Mind wandering predicted creative improvement only for those who returned to the same prompt, not for those who started fresh [3]. In other words, the drifting mind seems to help by quietly loosening a problem you are still holding, rather than by boosting creativity in general.
This is where individual differences could enter without being about intelligence. A person who keeps a problem mentally alive during a break, even while thinking about something else, may be positioned to gain more from incubation than someone who lets it go entirely. The study did not measure that trait directly, so this remains a plausible reading rather than a demonstrated one [3].
Incubation may matter most for people prone to getting stuck
The most direct evidence on ability comes from a problem-solving study that placed an incubation period between two thirty-second attempts at creative problems. The finding was that incubation reduced the need for active inhibition, meaning people did not have to work as hard to suppress misleading ideas that were blocking a solution [5]. That framing suggests incubation is doing repair work: it helps when the obstacle is mental fixation on a wrong approach, not when the obstacle is a lack of ideas.
Read alongside the mind-wandering results, this implies a specific prediction about who benefits: people who fixate easily, or who find it hard to set aside a tempting wrong answer, should gain the most from a break. The study is consistent with that, but it tested the mechanism of incubation rather than comparing high- and low-ability individuals head to head, so the who question is inferred rather than measured [5].
Why a clean answer about ability is still missing
Several of these studies deliberately set ability aside. The multitask work on incubation focused on how incentive schemes and task structure shape whether incubation pays off, not on differences between people [1]. The mind-wandering research controlled for pre-existing differences rather than examining them as the question of interest [2]. And the writing experiments did not assess individual ability at all [3][4].
So the honest answer is that the field has good evidence about the conditions of incubation and almost none about ability as a moderator. What exists points toward a testable idea: incubation may be a leveller, helping most those whose thinking is stuck rather than those who are already fluent [5], while the amount of spontaneous mind wandering during the break predicts who actually cashes in [3]. Whether measured ability predicts the size of the gain is a question these studies leave open.
Sources used in this answer
The elusive benefits of mind wandering: How incentive scheme and task structure facilitate creative incubation in a multitask environment
Incentive schemes and task structure in a multitask setting shape whether creative incubation produces benefits, rather than individual ability differences.
Mind wandering outside the box—About the role of off-task thoughts and their assessment during creative incubation.
Off-task thoughts and mind wandering during incubation are linked to creative insight, with pre-existing individual differences controlled for rather than examined.
Mind wandering during creative incubation predicts increases in creative performance in a writing task
Greater mind wandering during a ten-minute incubation break predicted greater creative improvement in a writing task, but only for participants who returned to the same prompt.
Mind Wandering During Incubation Predicts Creative Improvement in Writing Task
Mind wandering during incubation appears to predict creative improvement in a writing task, though the study notes limits on its ability to detect significant effects.
Escaping mental fixation: Incubation and inhibition in creative problem solving
An incubation period between problem-solving attempts reduced the need for active inhibition, suggesting incubation helps by easing mental fixation.