, 75 (2014);345 Science
et al.Timothy D. Wilson
Just think: The challenges of the disengaged mind
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or by postsynthesis treatments (28,29). By con-
trast, separations such as H
that involve a
fast-permeating species are not appreciably af-
fected by membrane defects. IMMP is also in-
herently a modular and parallel approach that
should allow independent and simultaneous pro-
cessing of membranes in multiple fibers. To test
this hypothesis, we applied IMMP to the simulta-
neous processing of three hollow fibers. The total
bore flow rate was increased by a factor of 3 so
that the flow rate through individual fibers was
maintained. The ends of the module were capped
with PDMS, as described earlier. Figure 3, C and
D, shows that the H
aration behavior is essentially identical to the
single-fiber case, demonstrating the potential for
scalability of IMMP. Given the overall importance
of tunable ZIF materials for a range of hydro-
carbon and light-gas separations, the membrane-
processing approach reported here overcomes
many limitations of current processes and is a
notable step toward realizing scalable molecular
sieving MOF membranes.
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ACS Appl. Mater. Interfaces 3,3568–3582 (2011).
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29. J. M. S. Henis, M. K. Tripodi, Science 220,11–17 (1983).
ACKNOWL EDGME NTS
This work was supported by Phillips 66 Company. S.N., A.J.B.,
and C.W.J. conceived the research. A.J.B. and N.A.B. designed
the synthesis reactor. Hollow-fiber fabrication was carried out
by J.R.J. and W.J.K. Membrane synthesis, characterization, and
permeation measurements were carried out by A.J.B., K.E., and
F.R. Permeation modeling was carried out by S.N. and A.J.B.
All authors contributed to manuscript writing and editing. We thank
W. Qiu, R. P. Lively, and A. Rownaghi (all at Georgia Institute of
Technology) for helpful discussions. The Supplementary Materials
includes a detailed description of materials and methods, details
of the IMMP reactor, time-dependent flow profiles and synthesis
cases, SEM images of ZIF-8 membranes, XRD patterns of
membranes, schematics of permeation apparatus and gas bypass
effects, EDX mapping of the ZIF-8 membrane, permeation
modeling equations, and gas permeation data. A patent application
related to this work has been filed [U.S. patent application
61/820,489, filed 7 May 2013; S. Nair et al., Flow processing
and characterization of metal-organic framework (MOF)
membranes in tubular and hollow fiber modules].
Materials and Methods
Figs. S1 to S11
Tables S1 to S4
22 January 2014; accepted 19 May 2014
Just think: The challenges of the
Timothy D. Wilson,
*David A. Reinhard,
Erin C. Westgate,
Daniel T. Gilbert,
Casey L. Brown,
In 11 studies, we found that participants typically did not enjoy spending 6 to 15 minutes in
a room by themselves with nothing to do but think, that they enjoyed doing mundane
external activities much more, and that many preferred to administer electric shocks to
themselves instead of being left alone with their thoughts. Most people seem to prefer to
be doing something rather than nothing, even if that something is negative.
“The mind is its own place, and in it self/
Can make a Heav'n of Hell, a Hell of Heav'n.”
–John Milton, Paradise Lost
The ability to engage in directed conscious
thought is an integral part—perhaps even
adefiningpart—of what makes us human.
Unique among the species, we have the abil-
ity to sit and mentally detach ourselves from
our surroundings and travel inward, recalling
the past, envisioning the future, and imagining
worlds that have never existed. Neural activity
during such inward-directed thought, called
default-mode processing, has been the focus of a
great deal of attention in recent years, and re-
searchers have speculated about its possible
functions (1–5). Two related questions, how-
ever, have been overlooked: Do people choose to
put themselves in default mode by disengaging
from the external world? And when they are in
this mode, is it a pleasing experience?
Recent survey results suggest that the answer
to the first question is “not very often.”Ninety-
five percent of American adults reported that
they did at least one leisure activity in the past
24 hours, such as watching television, socializ-
ing, or reading for pleasure, but 83% reported
they spent no time whatsoever “relaxing or think-
ing”(6). Is this because people do not enjoy having
nothing to do but think?
Almost all previous research on daydream-
ing and mind wandering has focused on task-
unrelated thought, namely cases in which people
are trying to attend to an external task (such as
reading a book), but their minds wander invol-
untarily (7,8). In such cases, people tend to be
happier when their minds are engaged in what
they are doing, instead of having wandered away
(9,10). A case could be made that it is easier for
people to steer their thoughts in pleasant direc-
tions when the external world is not competing
for their attention. We suggest, to the contrary,
that it is surprisingly difficult to think in enjoy-
able ways even in the absence of competing ex-
To address these questions, we conducted
studies in which college-student participants
spent time by themselves in an unadorned room
(for 6 to 15 min, depending on the study) after
storing all of their belongings, including cell
phones and writing implements. They were typ-
ically asked to spend the time entertaining them-
selves with their thoughts, with the only rules
being that they should remain in their seats and
stay awake. After this “thinking period,”partic-
ipants answered questions about how enjoyable
the experience was, how hard it was to concen-
Table 1 summarizes the results of six studies
that followed this procedure. Most participants
reported that it was difficult to concentrate
(57.5% responded at or above the midpoint of
the point scale) and that their mind wandered
(89.0% responded at or above the midpoint of
the scale), even though there was nothing com-
peting for their attention. And on average, par-
ticipants did not enjoy the experience very much:
49.3% reported enjoyment that was at or below
the midpoint of the scale.
SCIENCE sciencemag.org 4JULY2014•VOL 345 ISSUE 6192 75
Department of Psychology, University of Virginia,
Charlottesville, VA, USA.
Department of Psychology,
Harvard University, Cambridge, MA, USA.
*Corresponding author. E-mail: firstname.lastname@example.org
Perhaps the unfamiliar environs of the psy-
chological laboratory made it difficult for people
to become lost in and enjoy their thoughts. In
study 7, we instructed college-student participants
to complete the study at home, by clicking on a
link to a Web program when they were alone
and free of external distractions. Many partic-
ipants found it difficult to follow these instruc-
tions: 32% reported that they had “cheated”by
engaging in an external activity (such as listen-
ing to music or consulting their cell phones) or
getting up out of their chair. Furthermore, there
was no evidence that participants enjoyed the
experience more when they were in the privacy
of their homes. The mean reported enjoyment was
lower when they were at home than when they
were in the laboratory [t(188) = 2.47, P=0.014],
and participants reported that it was harder to
concentrate on their thoughts when they were at
home [t(188) = 2.87, P=0.005](Table1).These
differences must be interpreted with caution, be-
cause we did not randomly assign participants to a
location, but they suggest that just thinking is no
easier at home than it is in the laboratory.
Would participants enjoy themselves more
if they had something to do? In study 8, we
randomly assigned participants to entertain
themselves with their own thoughts or to en-
gage in external activities (such as reading a
book, listening to music, or surfing the Web).
We asked the latter participants not to commu-
nicate with others (e.g., via texting or emailing),
so that we could compare nonsocial external ac-
tivities (such as reading) with a nonsocial internal
activity (thinking). As seen in Table 1, participants
enjoyed the external activities much more than
just thinking [t(28) = 4.83, P< 0.001], found it
easier to concentrate [t(28) = 4.16, P<0.001],
and reported that their minds wandered less
[t(28) = 3.61, P= 0.001].
To see whether the difficulty with “just think-
ing”is distinctiv e to college s tudents, in study
9 we recruited community participants at a
farmer’s market and a local church. The par-
ticipants ranged in age from 18 to 77 (median
age = 48.0 years). As in study 7, they completed
the study online in their own homes, after re-
ceiving instructions to do so when they were
alone and free of any external distractions. The
results were similar to those found with college
students. There was no evidence that enjoyment
of the thinking period was related to partici-
pants’age, education, income, or the frequency
with which they used smart phones or social
media (table S2).
There was variation in enjoyment in our
studies, and we included several individual dif-
ference measures to investigate what sort of
person enjoys thinking the most (summarized
in table S3). The variables that consistently pre-
dicted enjoyment across studies were items from
two subscales of the Short Imaginal Process
Inventory (11). The Positive Constructive Day-
dreaming subscale (e.g., “My daydreams often
leave me with a warm, happy feeling”)corre-
lated positively with enjoyment, and the Poor
Attentional Control subscale (e.g., “Itendtobe
ment. None of the other correlations exceeded
0.27 (table S3).
So far, we have seen that most people do not
enjoy “just thinking”and clearly prefer having
something else to do. But would they rather do
an unpleasant activity than no activity at all? In
study 10, participants received the same instruc-
tions to entertain themselves with their thoughts
in the laboratory but also had the opportunity
to experience negative stimulation (an electric
shock) if they so desired. In part 1 of the study,
participants rated the pleasantness of several
positive stimuli (e.g., attractive photographs)
and negative stimuli (e.g., an electric shock). Par-
ticipants also reported how much they would
pay to experience or not experience each stim-
ulus again, if they were given $5. Next, partic-
ipants received our standard instructions to
entertain themselves with their thoughts (in this
case for 15 min). If they wanted, they learned,
they could receive an electric shock again during
the thinking period by pressing a button. We
went to some length to explain that the pri-
mary goal was to entertain themselves with
their thoughts and that the decision to receive
a shock was entirely up to them.
Many participants elected to receive nega-
tive stimulation over no stimulation—especially
men: 67% of men (12 of 18) gave themselves
at least one shock during the thinking period
[range = 0 to 4 shocks, mean (M)=1.47,SD=
1.46, not including one outlier who adminis-
tered 190 shocks to himself], compared to 25%
of women (6 of 24; range = 0 to 9 shocks, M=
1.00, SD = 2.32). Note that these results only
include participants who had reported that they
would pay to avoid being shocked again. (See
the supplementary materials for more details.)
The gender difference is probably due to the
tendency for men to be higher in sensation-
seeking (12). But what is striking is that simply
being alone with their own thoughts for 15 min
was apparently so aversive that it drove many
participants to self-administer an electric shock
that they had earlier said they would pay to avoid.
Why was thinking so difficult and unpleasant?
One possibility is that when left alone with
their thoughts, participants focused on their
own shortcomings and got caught in ru-
minative thought cycles (13–16). Research shows,
however, that self-focus does not invariably lead
to rumination (17), a finding that was confirmed
in our studies. At the conclusion of the thinking
period, we asked participants to describe what
they had been thinking about, and we analyzed
these reports with linguistic analysis software
(18). There was no relationship between the ex-
tent of self-focus (as assessed by the use of first-
person personal pronouns) and participants’
use of positive-emotion words, negative-emotion
words, or reported enjoyment of the thinking pe-
riod correlations = 0.033, 0.025, and 0.022, re-
spectively; 218 participants, ns) (see table S4 for
other results of the linguistic analyses).
Another reason why participants might have
found thinking to be difficult is that they simul-
taneously had to be a “script writer”and an
to think about (“I’ll focus on my upcoming sum-
mer vacation”), decide what would happen
(“Okay, I’ve arrived at the beach, I guess I’ll lie
in the sun for a bit before going for a swim”), and
then mentally experience those actions. Perhaps
people would find it easier to enjoy their thoughts
if they had time to plan in advance wh at they
would think about. We tested this hypothesis in
studies 1 to 7. Participants were randomly assigned
to our standard “thinking period”condition (the
results of which are shown in Table 1) or to condi-
tions in which they first spent a few minutes
planning what they would think about. We tried
several versions of these “prompted fantasy”instruc-
tions (summarized in table S1) and found that
none reliably increased participants’enjoyment
of the thinking period. Averaged across studies,
participants in the prompted fantasy conditions
reported similar levels of enjoyment as did partic-
ipants in the standard conditions [M=4.97ver-
sus 4.94 (SDs = 1.80, 1.84), t(450) = 0.15, ns].
There is no doubt that people are sometimes
absorbed by interesting ideas, exciting fantasies,
76 4JULY2014•VOL 345 ISSUE 6192 sciencemag.org SCIENCE
Table 1. Reactions to the “thinking period”under different conditions.
Studies 1 to 6:
In the lab
Study 8: At home
Hard to concentrate†SD
*Mean of three items, each answered on nine-point scales: How enjoyable and entertaining the thinking
period was and how bored participants were (reverse-scored). Cronbach’salpha=0.89. †Extent to
which participants reported that it was hard to concentrate on what they chose to think about (nine-point
scale; the higher the number, the greater the reported difficulty). ‡Extent to which participants
reporte d that their mind wandered during t he thinking period (nine-point scale; the hig her the n umber, the
greater the reported mind-wandering).
and pleasant daydreams (19–21). Research has
shown that minds are difficult to control (8,22),
however, and it may be particularly hard to
steer our thoughts in pleasant directions and
keep them there. This may be why many people
seek to gain better control of their thoughts with
meditation and other techniques, with clear ben-
efits (23–27). Without such training, people prefer
doing to thinking, eve n if what they are doing is
so unpleasant that they would normally pay to
avoid it. The untutored mind does not like to be
alone with itself.
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1. M. E. Raichle et al., Proc. Natl. Acad. Sci. U.S.A. 98,676–682
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10. M. S. Franklin et al., Front. Psychol. 4,583(2013).
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Short Imaginal Processes Inventory: Manual (Research
Psychologists Press, Port Huron, MI, 1982).
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Psychol. Sci. 3,400–424 (2008).
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Inquiry and Word Count (LIWC.net, Austin, TX, 20 07).
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Experimental Study of Inner Experience (Random House, New
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27. J. W. Schooler et al., Psychol. Learn. Motiv. 60,1–33
We acknowledge the support of NSF grant SES-0951779. The data
from all studies can be accessed at https://osf.io/cgwdy/files/.
We thank J. Coan for his help with study 10 and E. Winkler, the
pastor of Wesley Memorial United Methodist Church, for his help in
recruiting participants for study 9.
Materials and Methods
Additional Analyses across Studies
Tables S1 to S4
14 Janua ry 2014 ; accep ted 10 Ju ne 2014
Climate change and wind
intensification in coastal
W. J. Sydeman,
D. S. Schoeman,
R. R. Rykaczewski,
S. A. Thompson,
B. A. Black,
S. J. Bograd
In 1990, Andrew Bakun proposed that increasing greenhouse gas concentrations would
force intensification of upwelling-favorable winds in eastern boundary current systems
that contribute substantial services to society. Because there is considerable disagreement
about whether contemporary wind trends support Bakun’shypothesis,weperformeda
meta-analysis of the literature on upwelling-favorable wind intensification. The preponderance
of published analyses suggests that winds have intensified in the California, Benguela,
and Humboldt upwelling systems and weakened in the Iberian system over time
scales ranging up to 60 years; wind change is equivocal in the Canary system. Stronger
intensification signals are observed at higher latitudes, consistent with the warming pattern
associated with climate change. Overall, reported changes in coastal winds, although subtle
and spatially variable, support Bakun’shypothesisofupwellingintensificationineastern
boundary current systems.
coastal upwelling fuels high productivity,
supporting vast and diverse marine popula-
tions. With a surface area of only ~2% of the
global oceans, EBCSs provide upward of 20%
of wild marine-capture fisheries (1)aswellas
essential habitat for marine biodiversity (2).
Understanding upwelling variability is also key
to assessments of marine ecosystem health, in-
fluencing factors such as ocean acidification and
deoxygenation (3–5). Although the ecological
relevance of upwelling is clear, the future of up-
welling under anthropogenic climate change is
not (6–8). In 1990, Andrew Bakun hypothesized
that global warming could result in steeper tem-
perature and sea-level pressure gradients be-
tween the oceans and the continents, causing
alongshore upwelling-favorable winds to inten-
sify (6). Although the increase in global tem-
peratures is unquestioned (7), its influence on
upwelling-favorable winds remains uncertain.
In an attempt to resolve disagreement in the
literature concerning the intensification of up-
welling winds, we conducted a “preponderance
of evidence”meta-analysis on results from pre-
vious studies that tested Bakun’swindintensi-
fication hypothesis. Our meta-analysis focused
on the outcome of Bakun’spurportedmechanism:
upwell ing- favo rabl e wind intensification over
the past 6+ decades.
We synthesized results from 22 studies published
between 1990 and 2012, 18 of which contained
quantitative information o n wind trends. Ou r re-
sulting database contains 187 non-independent
wind trend analyses based on time series rang-
ing in duration from 17 to 61 years [tables S1 to
S3 (9)]. We tested whether the evidence from
these studies was consistent (increasing winds)
or inconsistent (weakening winds) with the Bakun
hypothesis. Bakun proposed that winds would
intensify in the upwelling or warm season; i.e.,
May to August in the Northern Hemisphere and
November to February in the Southern Hemi-
sphere. Therefore, we categorized each trend
based on the months averaged for its calculation:
“warm season”or “annual”(all months). Bakun
surmised that there would be latitudinal varia-
tion in wind trends and predicted that the most
substantial intensification would be in the “core”
of each EBCS. Therefore, to test for spatial het-
erogeneity in wind trends, we included absolute
latitude in our models (9). We compared results
from observational data and model-data re-
analysis products, because previous research has
shown different trends among these data types
We used logistic regression to model the con-
sistency of wind trends with the Bakun hypothesis.
Although all studies included in our analysis
undertook formal statistical analysis, they used
different analyses and stati stic al app roac hes
and also used a range of significance levels (0.01
to 0.10), many of which were reported only cat-
egorically (9). Consequently, we used a qualitative
approach (table S3) in which we down-weighted
nominally nonsignificant trends to half the weight
SCIENCE sciencemag.org 4JULY2014•VOL 345 ISSUE 6192 77
Farallon Institute for Advanced Ecosystem Research, Suite
Q, 101 H Street, Petaluma, CA 94952, USA.
Science, Health, Education and Engineering, University of the
Sunshine Coast, Locked Bag 4, Maroochydore DC,
Queensland 4558, Australia.
Department of Biological
Sciences and Marine Science Program, University of South
Carolina, 701 Sumter Street, Columbia, SC 29208, USA.
Climate Impacts Group, University of Washington, Box
355674, Seattle, WA 98195, USA.
Marine Science Institute,
University of Texas, 750 Channel View Drive, Port Aransas,
TX 78373, USA.
Environmental Research Division, National
Oceanic and Atmospheric Administration (NOAA) Southwest
Fisheries Science Center, 1352 Lighthouse Avenue, Pacific
Grove, CA 93950-2097, USA.
*Corresponding author. E-mail: email@example.com