A Wandering Mind Is an
Matthew A. Killingsworth* and Daniel T. Gilbert
nlike other animals, human beings spend
going on around them, contemplating
events that happened in the past, might happen
in the future, or will never happen at all. Indeed,
“stimulus-independen t thought” or “mind wan-
dering” appears to be the brain’sdefaultmode
of operation (1–3). Although this ability is a re-
markable ev o lutio nary ac h iev ement th a t al lows
people to learn, reason, and plan, it may have an
emotional cost. Many philosophical and religious
traditions teach that happiness is to be found by
living in the mom e nt , an d p r a ct i ti on e rs are trai n ed
to resist mind wandering and “to be here now .”
These traditio ns suggest that a wandering mind is
an unhappy mind. Are they right?
Laboratory experiments have revealed a great
deal about the cognitive and neural bases of mind
wandering (3–7), but little about its emotional
conseque nces in everyday life. The most reliab le
met hod f or in ve st ig at in g rea l- wo rl d emo ti on i s ex-
perience sampling, which involves contacting peo-
ple as they engage in their everyday activities and
asking them to report their thoughts, feelings, and
actions at that moment. Unfortunately, collecting
real-time reports from lar ge numbers of people as
they go about their daily lives is so cumbersome
and expensive that experience sampling has rarely
been used to investigate the relationship between
mind wandering and happiness and has always
been limited to very small samples (8, 9).
We solved this problem by developing a Web
application for the iPhone (Apple Incorporated,
Cupertino, California), which we used to create
an unusually large database of real-time reports
of though ts, feelings, and actions of a broad range
of people as they went about their daily activ-
ities. The application contacts participants through
their iPhones at random moments during their
waking hours, presents them with questions,
and records their answers to a database at www.
trackyourhappiness.org. The database currently
contains nearly a quarter of a million samples
from about 5000 people from 83 different coun-
tries who range in age from 18 to 88 and who
collectively represent every one of 86 major oc-
To find out how often people’smindswander,
what topics they wander to, and how those wan-
derings affect their happiness, we analyzed samples
from 2250 adults (58.8% male, 73.9% residing in
the United States, mean age of 34 years) who were
randomly assigned to answer a happiness question
(“How are you feeling right now?”)answeredona
continuous sliding scale from very bad (0) to very
good (100), an activity question (“Wh at are you
doing right now?”)answeredbyendorsingoneor
more of 22 activities adapted from the day recon-
struction method (10, 11 ), and a mind-wandering
question (“Are you thinking about som e t hi n g
other than what you’re currently doing?”)answered
with one of four options: no; yes, something pleas-
ant; yes, something neutral; or yes, something un-
pleasant. Our analyses revealed three facts.
gardless of what they were doing. Mind wandering
occurred in 46.9% of the samples and in at least
30% of the samples taken during every activity
exce pt making love. The frequ e ncy of mind wan-
dering in our real-world sample was considerably
higher than is typically seen in laboratory experi-
ments. Surprisingly, the nature of people’sactiv-
ities had only a mod est impact on whether their
minds wandered and had almost no impact on the
pleasantness of the topics to wh ich their minds
Second, multilevel regression revealed that peo-
ple were less happy when their minds were wan-
dering than when they were not [slope (b)=–8.79,
including the least enjoyable. Although people’s
minds were more likely to wander to pleasant topics
(42.5% of samples) than to unpleasant topics
(26 . 5 % of sa m p le s ) or neu t ra l to p i c s (31 % of sam -
ples), people were no happier when thinking about
pleasant topics than about their current activity (b =
–0.52, not significant) and were considerably un-
happier when thinking about neutral topics (b =
–7. 2, P <0.001)orunpleasanttopics(b = –23.9,
bottom). Although negative moods are known
to cause mind wandering (13), time-lag analyses
strongly suggested that mind wandering in our
sample was generally the cause, and not merely
the consequence, of unhappiness (12).
Third, what people were thinking was a better
predictor of their happiness than was what they
were doing. The nature of people’sactivitiesex-
plained 4.6% of the within-pe rson variance in hap -
piness and 3.2% of the between-person variance in
happiness, but mind wandering explained 10.8%
of within-person variance in happiness and 17.7%
of between-person variance in happiness. The var-
iance explained by mind wandering was largely
independ ent of th e varia nce exp la ined b y the na-
ture of activities, suggesting that the two were in-
dependent influences on happiness.
In conclusion, a human mind is a wandering
mind, and a wan de ri ng mind is an unh ap py mind .
The ability to think about what is not happening
is a cognitive achievement that comes at an emo-
References and Notes
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12. Materials and methods are available as supporting
material on Science Online.
13. J. Smallwood, A. Fitzgerald, L. K. Miles, L. H. Phillips,
14. We thank V. Pitiyanuvath for engineering www.
trackyourhappiness.org and R. Hackman, A. Jenkins,
W. Mendes, A. Oswald, and T. Wilson for helpful comments.
Supporting Online Material
Materials and Methods
18 May 2010; accepted 29 September 2010
Harvard University, Cambridge, MA 02138, USA.
*To whom correspondence should be addressed. E-mail:
Fig. 1. Mean happiness reported during each ac-
ant topics, neutral topics, pleasant topics or not
mind wandering (bottom). Dashed line indicates
mean of happiness across all samples. Bubble area
indicates the frequency of occurrence. The largest
bubble (“not mind wandering”)correspondsto
53.1% of the samples, and the smallest bubble
0.1% of the samples.
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