How Much Thought Is Inactive?

19 December 2019

How much of your mental life is intentional action? And how much of it consists of inaction, not doing anything at all? To answer that, we need to get clear on what we mean by “intentional action” and “inaction.”


When you do something intentionally, you have in mind what you are trying to do. You can tell someone what you’re up to. And in the realm of intentional action, you can do something in order to do something else. You can intend to perform a means to an end. You can do all sorts of things intentionally—snap your fingers, knead dough, run a marathon, paint a wall. When you do any of those things, you have in mind what you’re trying to do; you can tell someone what you’re up to; and you might even have a further end in mind.



Inaction, by definition, does not involve acting on some goal or trying to do anything at all. Sometimes we call physical inaction “lying around,” which implies that your body is not moving much, but that can be misleading. A physically inactive person’s heart is beating, and her lungs are expanding and contracting. In this context, inaction does not mean total lack of movement. When you're inactive, you simply go with the flow.


The same applies for mental inaction: it doesn’t imply that your thoughts are stationary (whatever that might mean). Rather, mental inaction involves going with the flow again—that means the stream of consciousness, wherever it might take you. This kind of thought is what philosopher and cognitive scientist Zac Irving has studied under the label “mind-wandering:” it’s the kind of thought that doesn’t involve guiding your attention to any particular thing at all. This lack of guidance means you just let your mind run wherever it feels like running.


Such mental inaction contrasts with directed thought of various kinds. You can do all sorts of things intentionally in thought. You can intentionally recall what you ate for breakfast. You can intentionally solve a math problem in your head. Doing any of these things involves guiding your thoughts in a particular way. 


Now that we’ve gotten a better understanding of what we’re talking about, we can ask our question again. How much of your mental life is taken up by action, and how much inaction?


The best way to study this is to sample people’s lived experience as they are going about their daily lives. For instance, you can ping people’s phones at random moments over the course of a few days and ask them questions about their present thoughts in order to probe whether those thoughts are intentional or not—for our purposes, active or inactive. Many studies in the last decade or so have done studies of exactly this kind. The explosion of research suggests that mind wandering can take up to half the time of your mental life. Based partly on this research, the philosopher Thomas Metzinger has suggested that you lack mental autonomy in two thirds of your mental life.


But there is a serious problem with these empirical studies—at least as they apply to our question. They don’t really probe whether thinkers are engaged in intentional mental action or not. That is because the questions that they ask people to answer don’t settle that.


The first question these studies usually ask after the ‘ping’ is about whether your thoughts at the time of the ‘ping’ were related to your activity or not. Mills et al. asked “Were you thinking about something other than what you were doing?” Jazaieri et al. asked “Are you thinking about something other than what you’re currently doing?” Similarly, Kane et al. and Song and Wang asked participants to rate whether “my mind had wandered to something other than what I was doing.”


These questions make it sound as though there is just one thing that a person is doing at a time. Moreover, the setup of these studies encourages participants to think about that one thing as the unique external  task they are supposed to be working on. That could be solving a math problem, or cooking dinner, or something else. When asked, then, whether they were thinking about the thing they were doing, participants just assess whether their thoughts at the time are related to that one target.


But your thoughts at any time could be related to a great many targets. Indeed, many kinds of distractions come about when you realize you could be doing something else in thought—planning your dinner, for example. If you stop thinking about your external task and start doing one of these things, you haven’t relinquished your mental autonomy. In fact, it might look as though you have asserted your mental autonomy in another kind of intentional action, which you simply felt like doing at the time. You can intentionally plan your dinner, even if that is not what you are supposed to be doing at the moment.


Even if your distracted, off-task thoughts do wander from place to place that itself can be intentional. This is a point Fabian Dorsch and Zac Irving have made. Sometimes your thoughts simply wander. But sometimes you intentionally let your thoughts wander. To say that you do this intentionally is to say that you have in mind what you’re trying to do; you could tell someone what you’re up to (letting your mind wander…); and you could do that as a means to an end (resting your mind).


The better studies recognize this possibility, and they ask subjects explicitly whether they were letting their minds wander “on purpose” or “deliberately”. If we look at how participants responded to this question, we get a quite different picture of the scope of mental agency than the one we considered above. The incidence of mind-wandering in these random samples of everyday life varies from around 30% to about 60%. But in each study that tested for purposeful mind-wandering, about half of those instances of mind-wandering are classified by participants as purposeful. As Kane and colleagues put it, “On occasions when subjects reported off-task thought, they generally expressed little surprise that their mind had wandered, and indicated that they had mentally disengaged on purpose.” That sounds a lot like intentional action to me.


If we count intentional mind-wandering as intentional mental action then we can estimate that intentional mental action makes up about 65 – 80% of our mental lives. That’s a far cry from the erosion of agency and mental autonomy that some claim the research into mind-wandering suggests.


What should we learn from this? At least, we should see that mind-wandering and intentional mental action are compatible. The research into mind-wandering doesn’t tell us all we want to know about intentional mental action, nor about mental agency or autonomy more generally. But it also suggests that we should come up with better questions to ask people in order to probe how often they engage in intentional mental actions. To their credit, Mills et al. were doing just that. I’m excited to see the next stage in research into mind wandering.


Image by Colin Behrens from Pixabay

Comments (2)

Tim Smith's picture

Tim Smith

Thursday, December 19, 2019 -- 3:58 PM



Thank you for this insightful and well written essay.

I counted and my mind wandered 3 times when I read this the first time (I reconstructed this) ... and 5 times when I read it the second (intentionally counting as I went.) This might be one area of exploration that I would find interesting and I'm wondering if your excitement might be pointed in that direction as well?

Learning, understanding and brain storming are three activities that – if you would indulge me - ‘come to mind’ when thinking of “intentional” mental action that spawns mental wandering.

To call something 'thought provoking' takes on a new meaning in and around questions of mental agency. I would extend that to human agency as well. In the end it argues strongly if not definitively as an argument for the lack of free will.

I say this without fear of rebuttal or counter proof. ==> All thought could be termed inactive, though clearly you are not doing so here.

Human agency is greatly compromised and excluded by previous reasons. This is not to say that the future is preordained. Reasons have complex interactions and tipping points that give personal and universal history a seeming aura of agency.

This agency is a fundamental cornerstone of human consciousness in the traditional sense of that term.

Stanford’s own Robert Sapolsky has schooled me on the lack of human agency multiple times. Each time it has set my mind wandering but always to return by Occam’s razor to the hypothesis that free will is not free.

Whether that hypothesis is ever proven (mostly due to dullards like myself refusing to question their own thought) I can think of at least three other areas of excitement in and around inactive mental thought.

The first would be the double edged sword of senescence and dementia. There have been cases of amyloid plaque ridden nuns and decrepit sharp thinking philosophers (more of the former than the later I would posit) who would deny the affects of age on the brain. In general however, we must be resigned to a larger unintentional mental wandering in our dotage. I would like to see this data.

Second, I would have to point toward, if not blame fully, the legalization of marijuana as an example of drug induced mental wandering. Given the climatic change that is our seeming human purpose I don’t blame people, however, who indulge escapist or euphoric wandering to ‘deal’ with their fated lives. Microdosing, if I read Michael Pollan’s recent book played a role in the coding of our silicon dreams in and around your own campus (and elsewhere … there’s blame to spread everywhere…)

I think I might have lost a few readers (as is my purpose) here. Minds do wander.

Drugs, like video games, like sex have their own agendas for the minds that follow that path. I’d like to see the mental wandering and attending data on this population of minds.

Lastly let me come full circle, many people are not able to focus at all. Books are a challenge for these people and this is the greatest and most pointed return on investment for whom this research would bear fruit. I would like to see data of readers. How many can even visit this response to this point and hold intention (mea culpa.) That would vary greatly by subject and animation I would think. Fewer movie goers wander than readers I would say... but would also need to see the data.

I’m partial to graphic novels - BTW- which have their own distractions and action.

Thanks for linking the philosophers and scientists working here. I will follow them and try not to lose my way in the process.

Harold G. Neuman's picture

Harold G. Neuman

Friday, December 20, 2019 -- 12:39 PM

I agree with the above

I agree with the above comments regarding the essay. It is a fine piece of neuroscience and I expect my friend in Ecuador would agree. The broad brush of Philosophy Talk has always been a plus for the blog and its progenitors. I would like to see more philosophy, but recognize that such might detract from the overall mission. Kudos to all, especially Peacocke.