Comment on: A Wandering Mind Is an Unhappy Mind by Matthew A. Killingsworth and Daniel T. Gilbert

In this study, the authors asked study participants to rate their feelings, current activities and mind wandering. The authors state that the results revealed study participants “were less happy when their minds were wandering than when they were not and were considerably unhappier when thinking about neutral topics… or unpleasant topics than about their current activity”. Although participants’ minds “were more likely to wander to pleasant topics (42.5% of samples) than to unpleasant topics (26.5% of samples) or neutral topics (31% of samples), they were no happier when thinking about pleasant topics than about their current activity.” The authors conclude “a wandering mind is an unhappy mind”.

Is this a reasonable conclusion? Let’s look more closely at the evidence: subjects answered a happiness question (“How are you feeling right now?”) on a scale from very bad (0) to very good (100). Now I’m assuming that for most people, anything under 50 would be leaning unhappy – from a little bit to a whole lot – and anything over 50 would be leaning happy. Here are the approximate* mean happiness scores for mind wandering categories: pleasant mind wandering – 69; neutral mind wandering – 61; and, unpleasant mind wandering – 42. Ok, stating the obvious: except for unpleasant mind wandering, these means do not reflect unhappiness. And is it even newsworthy that unpleasant mind wandering is associated with unhappiness, given that “unpleasant” and “unhappy” generally go together? It’s like saying “When I think unhappy thoughts, I feel unhappy”. Duh.

The authors’ unwarranted conclusion, and the title of their paper, isn’t even an example of calling the glass half empty. It’s calling a glass that’s three-quarters full half empty.

*I say “approximate” because for some reason the authors only show the means as bubbles on a graph but don’t provide the exact numbers.


Killingsworth MA, Gilbert DT (2010) A wandering mind is an unhappy mind. Science 330:932.

Note: This is a slightly revised version of a previous post with the same title.