March 8, 2015
Mind wandering can be useful
When we are mind wandering we have spontaneous thoughts, thoughts which are not triggered by any external stimulus. When having spontaneous thoughts a circuit in the brain becomes more active which is called the default mode network (DMN), sometimes also simply called the default network (DN). A question which many people ask is what the function and effects of mind wandering are. It is often thought that mind wandering is not very good for people because it can lead to rumination and negative feelings. This is not a strange thought because some forms of psychopathology are associated with an excessive or deviant activity of the DMN (see here, here, and here). On the other hand, there are also indications that DMN activity has an important social function (see here and here).
Killingworth & Gilbert (2010) researched the effects of mind wandering on how happy people feel. They concluded that people often mind wander and that they often feel less happy when they mind wander than when they focus on an activity they are doing. Even when people mind wander about a positive subject they do not feel better than when they focus on their activity. In a later publication Wilson et al. (2014) came to comparable findings based on a series of experiments. They say that people prefer not to be alone with their thoughts and rather do something, like performing a task. They say that people would even rather do something negative (like giving themselves electrical shocks) than to do nothing and just think. Now, it looks like there are two types of objections to their conclusions.
Is spontaneous thought really unpleasant? The first type of objection focuses on these previous researcher's conclusions. Fox et al. (2014) were surprised by the findings by Wilson et al. (2014) and Killingworth & Gilbert (2010) because, according to them, these findings were in contrast with earlier findings which suggested that mind wandering was generally experienced as mildly positive (in this file you can see which studies they cite). Fox et al. examined Wilson et al.'s dataset and concluded that Wilson et al.'s conclusions were based on wrong interpretations of their own data and say these data actually support earlier research findings that spontaneous thought, on average, is experienced as mildly pleasant and that there is much variation in how pleasant people find it.
Is it only about pleasure? A second type of objection is that Killingworth & Gilbert (2010) and Wilson et al. (2014) have only looked at how happy people were during spontaneous thought while this is not the only criterion which is important. Couldn't it be so that the effects of mind wandering go far beyond leading to a pleasant of unpleasant feeling? That, indeed, seems to be the case. According to Morewedge et al. (2014) people can perceive that spontaneous thought leads to a better self-insight. According to Baars (2010) spontaneous thought plays an important adaptive role in solving life problems. According to Christoff et al. (2011) spontaneous thought can give meaning to our lives. Baird et al. (2011) say that mind wandering plays an important role in planning your future. Smallwood et al. (2013) say that spontaneous thoughts help in achieving long term goals. Mooneyham et al. (2013) say that spontaneous thoughts can play a crucial role in autobiographical planning and creative problem solving (also see Smallwood et al. 2011).
Conclusion: mind wandering does not seem to be so bad. It would be too simple to say that we should always avoid it. When we are doing goal-directed activities it seems best to keep mind wandering to a minimum (see here), But in different situations mind wandering may be useful. A way to allow for some mind wandering is to do some simple tasks. Baird et al. (2012) say that doing simple tasks creates the opportunity for mind wandering which fosters creative problem solving.
In short: sometimes it is important to be completely focused on an external task or activity. At other times it is wise to make room for spontaneous thought.