Claims about how often minds wander come from a specific research method. Understanding how attention is sampled explains both what those findings can support and what they cannot.
Sampling replaces recall
Asking people at the end of a day how attentive they were produces poor data, because memory for ordinary mental states is reconstructed rather than retrieved.
Experience sampling instead interrupts participants at unpredictable moments and asks what they are doing, what they are thinking about and how they feel right now.
The randomness is essential. A predictable prompt would be anticipated, and anticipation changes the state being measured.
The questions define the categories
A typical prompt asks whether the person is thinking about something other than what they are doing, which is the operational definition of mind-wandering in this literature.
Additional items ask whether the wandering content was pleasant, unpleasant or neutral, and this separation matters because the two dimensions do not move together.
Everything the method can report is fixed by these question choices, so the definition used in a given piece of research determines what its numbers mean.
Measurement disturbs the thing measured
A prompt interrupts. It ends the state it is asking about and, over a study period, trains participants to notice their own attention more than they otherwise would.
That noticing is essentially what mindfulness practice trains, which makes the boundary between the measurement and an intervention less clean than it appears.
Studies address this by limiting the number of prompts and by including baseline periods, but the effect is a known limitation rather than one that is eliminated.
Self-report is the only available channel
There is no external instrument that reads what someone is thinking about. Physiological measures indicate arousal and engagement but cannot identify the content of a thought.
The method therefore depends on participants noticing and reporting accurately, and people differ substantially in how well they can do that.
Someone with a long meditation practice may report more wandering than a novice, not because their attention is worse but because they detect it more readily.
What the findings support
Sampling studies establish that attention departs from the current task frequently, across ordinary activities, and that people generally underestimate how often.
They also indicate that the relationship between wandering and mood runs in both directions, which is more interesting than a simple claim that wandering is harmful.
They do not establish that any particular practice fixes it, since that requires a different study design with a comparison group and a defined intervention.