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The Journal of Positive Psychology
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Manipulating optimism: Can imagining a best possible self be used to
increase positive future expectancies?
Madelon L. Petersa; Ida K. Flinkb; Katja Boersmab; Steven J. Lintonb
a Department of Clinical Psychological Science, Maastricht University, MD, Maastricht, The
Netherlands b Center for Health and Medical Psychology (CHAMP), School of Law, Psychology, and
Social Work, Örebro University, Örebro, Sweden
Online publication date: 23 June 2010
To cite this Article Peters, Madelon L. , Flink, Ida K. , Boersma, Katja and Linton, Steven J.(2010) 'Manipulating optimism:
Can imagining a best possible self be used to increase positive future expectancies?', The Journal of Positive Psychology,
5: 3, 204 — 211
To link to this Article: DOI: 10.1080/17439761003790963
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The Journal of Positive Psychology
Vol. 5, No. 3, May 2010, 204–211
Manipulating optimism: Can imagining a best possible self be used to
increase positive future expectancies?
Madelon L. Peters
a
*, Ida K. Flink
b
, Katja Boersma
b
and Steven J. Linton
b
a
Department of Clinical Psychological Science, Maastricht University, P.O. Box 616, 6200,
MD, Maastricht, The Netherlands;
b
Center for Health and Medical Psychology (CHAMP),
School of Law, Psychology, and Social Work, O
¨rebro University, O
¨rebro, Sweden
(Received 8 July 2009; final version received 27 January 2010)
This study tested whether a brief manipulation consisting of positive future thinking can temporarily increase
optimism. Participants in the positive future thinking condition (n¼44) wrote about their best possible self (BPS)
for 15 min, followed by 5 min of mental imagery. Participants in the control condition (n¼38) wrote about and
imagined a typical day in their life. Positive and negative future expectancies and positive and negative affect were
measured before and after each manipulation. Compared to the control manipulation, the positive future
thinking manipulation led to significantly larger increase in positive affect and positive future expectancies.
The increase in positive expectancies was not dependent on the mood effect. The results indicate that imagining
a positive future can indeed increase expectancies for a positive future.
Keywords: optimism; manipulation; best possible self; positive and negative affect; future expectancies
Introduction
Optimism is defined as ‘the tendency to believe that
one will generally experience good outcomes in life’. In
recent years, many papers have been devoted to the
positive consequences of optimism. Optimists experi-
ence higher positive affect (PA) and well-being
(Andersson, 1996; Scheier & Carver, 1992; Wrosch &
Scheier, 2003), are more resilient to negative events
(Kivima
¨ki et al., 2005), experience better health
(Giltay, Kamphuis, Kalmijn, Zitman, & Kromhout,
2006; Scheier & Carver, 1992) and recover faster from
surgical procedures (Mahler & Kulik, 2000; Peters
et al., 2007; Scheier et al., 1999).
An important next step and a major challenge in
the research on optimism would be to develop a
manipulation to increase optimism. An effective opti-
mism manipulation would have both scientific and
clinical significance. Scientifically, such a manipulation
would be critical in demonstrating the causal link
between optimism and the positive consequences for
health and behaviour. Clinically, an effective manipu-
lation could be of benefit for improving the well-being
of people. Earlier, interventions have been developed
aimed at targeting optimism defined as explanatory
style, i.e. the way one makes attributions on the causes
of past events (Seligman, 1990). Indeed, these inter-
ventions have been shown to be successful in altering
attributional style (Gillham, Reivich, Jaycox, &
Seligman, 1995; Quayle, Dzuirawiec, Roberts, Kane,
& Ebsworthy, 2001; Riskind, Sarampote, & Mercier,
1996), but whether these interventions also changed
expectations of the future in a more positive direction
has not been examined.
The aim of this study was to explore whether it is
possible to (temporarily) increase positive expectancies
for the future by means of an experimental manipu-
lation. The availability of a brief but effective manip-
ulation to shift future expectancies in a positive
direction would be a useful research tool because it
allows conclusions on the causal status of optimism
and more in particular its cognitive future-oriented
component. Dispositional optimism shows relatively
strong inverse correlations with neuroticism and trait
anxiety, and it has been claimed that the beneficial
effects of optimism are attributable to its association
with these negative affective traits (Robbins, Spence,
& Clark, 1991; Smith, Pope, Rhodewalt, & Poulton,
1989). A manipulation specifically targeting expectan-
cies could rule out this alternative explanation.
In order to accomplish this goal, and consistent
with the definition of optimism, we searched for a
manipulation that would be able to induce global
positive outcome expectancies, i.e. encompassing
various life domains. The best possible self (BPS)
*Corresponding author. Email: Madelon.Peters@maastrichtuniversity.nl
ISSN 1743–9760 print/ISSN 1743–9779 online
ß2010 Taylor & Francis
DOI: 10.1080/17439761003790963
http://www.informaworld.com
Downloaded By: [Peters, Madelon L.] At: 15:20 25 June 2010
manipulation, which was first introduced by King
(2001), seems to meet this requirement. In the original
version of this manipulation, participants wrote for
20 min on 4 consecutive days about a future in which
they imagine themselves in the best possible condition
and circumstances. The BPS manipulation was found
effective in increasing PA, well-being and physical
health (Austenfeld, Paolo, & Stanton, 2006; Harrist,
Carlozzi, McGovern, & Harrist, 2007; King, 2001;
Sheldon & Lyubomirsky, 2006). These studies did not
specifically assess the potential of the BPS manipula-
tion to induce positive expectancies, although prelim-
inary evidence for an effect on optimism was provided
by King (2001). However, as the crucial comparison
also involved a traumatic writing condition (i.e. a
control condition and a traumatic writing condition
were compared to the BPS and a BPS þtraumatic
writing condition), the net effect of BPS on optimistic
cognitions cannot be determined.
In order to investigate whether writing about and
imagining a positive future has the potential to increase
optimistic future thinking, we compared the effects of a
single session of BPS exercise with that of a control
exercise (writing about and imagining a typical day) on
expectancies for positive and negative future outcomes.
Although previous studies have usually employed
repeated sessions of BPS writing, a single session of
BPS writing already proved significant in increasing
PA (Sheldon & Lyubomirsky, 2006). In an attempt to
maximize the effectiveness of the BPS exercise,
we added a 5-min mental imagery component to the
original writing exercise. It has repeatedly been shown
that mental imagery has stronger effects on emotions
and cognition than verbal processing of the same
material (Holmes, Lang, & Shah, 2009; Holmes,
Mathews, Mackintosh, & Dalgleish, 2008). According
to Holmes et al. (2009), people benefit more from
mental imagery than from verbal processing of highly
positive material because imagery is more absorbing
and believable and is less likely to result in unfavour-
able self-comparison.
An important issue is whether any effects of the
BPS manipulation on positive future expectancies are
independent from its previously demonstrated mood
effects, or whether these are secondary to the changes
in positive mood. Therefore, we measured PA and
negative affect (NA) prior to and following the
manipulation, and we examined whether the effect of
the manipulation on future expectancies are mediated
by the effects on mood. Finally, we explored whether
the effects of the BPS manipulation on expectancies for
the future and on mood are moderated by trait
optimism, neuroticism or extraversion. Previously, it
was found that writing about a BPS was equally
effective in reducing health care visits in optimists and
pessimists (Harrist et al., 2007). Therefore, we expected
that the impact of the BPS manipulation on
expectancies for the future and mood would not be
dependent on the participants’ a priori level of
optimism. Neuroticism and extraversion were included
as potential moderators for exploratory reasons.
In sum, three hypotheses were tested. First, BPS
writing and imagery leads to enhanced positive mood,
higher expectancies for positive future outcomes and
lower expectancies for negative future outcomes
compared to writing and imagining a typical day.
Second, the effects of the manipulation on future
expectancies are independent of its mood effects.
Confirmation of this hypothesis will provide evidence
that the BPS might be a true optimism manipulation
and not merely a mood induction. Finally, we hypoth-
esized that the effects of the BPS manipulation on
future expectancies and mood are not moderated by
trait optimism, neuroticism or extraversion.
Methods
Participants
The experiment was performed during first- and
fourth-year psychology classes at O
¨rebro University.
A total of 82 students (51 women and 31 men)
participated in the study. Mean age was 29.6 years
(range 21–50), 79 students were Swedish nationals and
for 77 students Swedish was their first language.
Manipulation
The manipulation was performed in the classroom
(9–19 students per class). The instructor informed
students that they were participating in an experiment
on the effects of a writing and imagery exercise on their
thoughts and feelings. Students from each participat-
ing class were randomly assigned to either of the two
conditions: the positive future thinking condition
(BPS) or the control condition (A typical day). Half
of the students remained in their classroom and
received one of the manipulations and the other half
were moved to a new room and received the alternative
manipulation. Both manipulations had the same
format: participants were requested to think for 1 min
about what to write, then write for 15 min, followed by
5 min of imagery on the story they just wrote.
Instructions were given both verbally and in writing.
The respective instructions in the BPS and typical day
condition were based on Sheldon and Lyubormirsky
(2006) and were as follows:
Best possible self:
The exercise you will do is to think about your best
possible self for one minute and then write down your
thoughts. ‘Think about your best possible self’ means
that you imagine yourself in the future, after everything
has gone as well as it possibly could. You have worked
hard and succeeded at accomplishing all the goals of
The Journal of Positive Psychology 205
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your life. Think of this as the realization of your dreams,
and that you have reached your full potential. Thus, you
identify the best possible way that things might turn out
in your life. Please, start thinking of your best possible
self. I will tell you when it is time to start writing down
your thoughts.
A typical day:
The exercise you will do is to think about a typical
day in your life for one minute and then write down your
thoughts. ‘Think about your typical day’ means that you
take notice of ordinary details of your day that you
usually don’t think about. These might include particular
classes or meetings you attend to, people you meet,
things you do, typical thoughts you have during the day.
Think of this as moving through your typical day, hour
after hour. Thus, you identify how a typical day looks
like for you. Please, start thinking of your typical day.
I will tell you when it is time to start writing down your
thoughts.
After a silence period of 1 min, the instructions
continued:
Now, I will ask you to write about your best possible
self/a typical day in your life for 15 minutes. The only
rule we have about writing is that you write continuously
for the entire time. If you run out of things to say, just
repeat what you have already written. Don’t worry about
grammar, spelling or sentence structure. Don’t worry
about erasing or crossing things out. Just write. The
things you write are only for yourself and do not have to
be handed in afterwards. If you need to repeat the
instructions for the exercise, you can read them at the
top of the paper in front of you. I will tell you when it is
time to stop writing. Please start writing.
Finally, after 15 min of writing, the instructions for the
imagery part were given:
Please, finish your sentences. The time for writing is
over. Now, I want you to imagine as vividly as possible
the things you have been writing about. Think about your
best possible self/a typical day in your life for 5 minutes.
Imagine your ideal future life/your typical day with as
much detail as you can. I will tell you when it is time to
stop. Please, start thinking.
A total of 44 students received the BPS manipula-
tion and 38 students received the typical day
manipulation.
Measures
Dispositional optimism
The life orientation test (LOT; Scheier & Carver, 1985)
was used to measure the level of dispositional opti-
mism of participants. The LOT has eight items
(plus four filler items) that are rated on a 5-point
scale (disagree–agree). Sample items are ‘Every
cloud has a silver lining’ and ‘I’m always optimistic
about my future’. Four items are positively phrased
and four items are negatively phrased. A total opti-
mism score can be obtained by summing all items after
reversing the scores on the negatively phrased items.
Internal consistency of the eight items was ¼0.76 in
this sample.
Extraversion and neuroticism
Two subscales of the Eysenck Personality
Questionnaire Revised Short Scale (EPQ-RSS;
Eysenck & Eysenck, 1991) were used to measure
extraversion and neuroticism. Each subscale has 10
yes/no items. A total score for each of the traits can
be obtained by summing all ‘yes’ answers. In the
extraversion subscale, two items are reverse scored,
and these items were first recoded. Internal consistency
in this sample was ¼0.75 for extraversion and
¼0.78 for neuroticism.
Affect
Affective state was assessed by the short form of the
positive and negative affect schedule (PANAS;
MacKinnon et al., 1999). The short PANAS contains
five items measuring PA (e.g. excited) and five items
measuring NA (e.g. distressed) that are scored on a
5-point scale. The frame of reference was the partic-
ipant’s state ‘right now’. An average item score is
calculated separately for PA and NA. The short
PANAS was administered twice: before the manipula-
tion and after the manipulation. Internal consistency in
this sample was ¼0.71 for the negative items and
¼0.73 for the positive items.
Expectancies for positive and negative future
outcomes
We used the subjective probability test (SPT;
MacLeod, 1996) to measure positive and negative
future expectancies. The SPT consists of 20 statements
referring to negative future outcomes (e.g. ‘you will
have health problems’, ‘things will not turn out as you
had hoped’) and 10 statements referring to positive
future outcomes (e.g. ‘you will be able to cope easily
with pressure’, ‘people will admire you’). Participants
are asked to judge the likelihood that they will
experience these specific outcomes on a 7-point scale
(not at all likely to occur – extremely likely to occur).
In a separate study with 254 participants (unpublished
results), we found that the positive items and the
negative items form two distinct factors, both with an
internal consistency of 40.90. Therefore, in the
analyses for this study, we used positive future expec-
tancies and negative future expectancies as two
separate constructs. Internal consistency in this study
was ¼0.80 and 0.91 for positive and negative future
expectancies, respectively. The SPT was administered
206 M.L. Peters et al.
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twice, but post-test the order of items was changed.
This version proved as internally consistent as the
original version (¼0.81 and 0.91 for positive and
negative future expectancies, respectively).
Quality of imagery and direct optimism questions
Four self-developed 10-point scales were administered
post-manipulation. Two scales were intended as an
additional measure of state optimism and related to the
future expectancies. These were respectively ‘What are
your expectations for the coming week?’ (it will be a
very bad week – it will be an excellent week) and ‘How
do you feel right now about your future?’ (very
pessimistic – very optimistic). The other two scales
related to the quality of imagery: ‘How well could you
imagine yourself being in the situation you described
in your writing?’ (not at all – extremely well) and ‘How
vivid were the pictures you imagined?’ (not vivid at
all – very vivid).
Procedure
All testing took place in the classroom. The students
sat on their own, next to each other. The experimenter
introduced the exercise and handed out the question-
naires. The questionnaires were completed in the
following order: PANAS, EPQ-RSS, LOT and SPT.
Next, the instructions appropriate for the conditions
were given by the experimenter, first verbally and then
in writing. A blank sheet of paper was provided for the
writing part. During the exercise, students were not
allowed to speak or leave the room. The experimenter
remained present during the entire procedure. After the
allotted time for writing and imagery had passed, the
experimenter signalled the students to finish. Next,
another set of questionnaires was provided, consisting
of the PANAS, SPT and the four visual analogue
scales (VASs). After finishing with the questionnaires,
students were free to leave, and could take their stories
with them. No remuneration was given for
participation.
Results
Baseline descriptives
Table 1 shows the mean scores of the participants
on the various questionnaires at baseline and their
intercorrelations. In accordance with previous findings
(McLeod, 1996 and our own unpublished data),
participants rated the probability of positive outcomes
higher than the probability of negative outcomes.
Attesting to their independence, expectancies for pos-
itive future outcomes and expectancies for negative
future outcomes appeared to be unrelated.
Dispositional optimism and – to a lesser extent –
extraversion were significantly correlated with expec-
tancies for positive future outcomes but not to expec-
tancies for negative outcomes. There was no significant
association of either type of expectancy with neurot-
icism or current mood.
Unexpectedly, there was a significant positive
correlation between PA and NA. There were no
baseline differences between the conditions on any of
the measures.
Effects of the manipulation
We first examined the subjective assessment of the
quality of imagination by participants. Most individ-
uals could very well imagine the situation (mean: 7.8,
SD: 1.8) and reported to have experienced vivid images
(mean: 7.9, SD: 1.9). There were no significant
differences in quality of imagination or vividness
between the two conditions.
The effects of the manipulation on changes in PA,
NA, expectancies for positive outcomes (SPT-pos) and
expectancies for negative outcomes (SPT-neg) were
tested with 2 2 (condition time) analysis of vari-
ances (ANOVAs) for repeated measures, using SPSS
15.0. Two participants (one in the BPS condition, other
in the control condition) did not provide a PANAS
score post-manipulation, and one participant (BPS
condition) did not provide an SPT score, leaving
80 and 81 participants for the analyses of affect and
state optimism, respectively. Results are displayed in
Table 2. A significant condition time interaction was
Table 1. Descriptive data and intercorrelations between questionnaires.
Mean (SD) Range EPQ-E EPQ-N PA NA SPT-pos SPT-neg
1 LOT 31.4 (4.8) 15–40 0.14 0.34* 0.14 0.02 0.58* 0.19
2 EPQ-E 8.35 (2.75) 0–12 0.00 0.12 0.01 0.35* 0.09
3 EPQ-N 3.65 (2.84) 0–10 0.05 0.21 0.20 0.18
4 PA 2.53 (0.71) 1.0–4.4 0.31* 0.06 0.02
5 NA 1.49 (0.54) 1.0–3.8 0.17 0.07
6 SPT-pos 5.45 (0.69) 3.2–7.0 0.07
7 SPT-neg 3.10 (0.95) 1.1–6.7
Note: *denotes Significance at p50.05.
The Journal of Positive Psychology 207
Downloaded By: [Peters, Madelon L.] At: 15:20 25 June 2010
found for PA. PA significantly increased after the BPS
manipulation (t¼6.92, p50.001) but not after the
control manipulation (t¼0.18, p¼0.86). For NA, only
the main effect of time was significant: there was a
slight but significant decrease in NA after both
manipulations (t¼3.06, p¼0.004 in the BPS condi-
tion; t¼2.31, p¼0.027 in the control condition).
For both SPT-pos and SPT-neg, the condition
time interaction effects were significant (Table 2).
Expectancies for positive outcomes significantly
increased after the BPS manipulation (t¼3.01,
p¼0.004) and remained unchanged after the control
manipulation (t¼0.81, p¼0.43). Expectancies for
negative outcomes significantly decreased after both
the BPS (t¼6.08, p50.001) and the control manip-
ulation (t¼6.80, p50.001), but the increase was
larger in the BPS condition.
T-tests for independent groups were used to test
whether there were differences between the conditions
on the two self-constructed post-manipulation ques-
tions intended to measure state optimism. A significant
difference neither for expectancies for the coming week
(mean BPS: 7.6; mean control: 7.7) nor for the future in
general (mean BPS: 8.3; mean control: 8.1) was found.
The expectation for the future in general did correlate
moderately with dispositional optimism (r¼0.23,
p¼0.039).
Mediation effects
Next we examined whether the effects of the manip-
ulation on expectancies for positive and negative
outcomes were mediated by the change in PA. We
used hierarchical regression analyses with either SPT-
pos or SPT-neg as the dependent variable and condi-
tion as the independent variable in the first step, and
added the pre- to post-manipulation change in PA in
the second step. This analysis indicated that the
increase in SPT-pos after the BPS manipulation
was not mediated by the increase in PA. The pre- to
post-manipulation change in PA was unrelated to the
change in SPT-pos ( ¼0.03) and the magnitude of
the condition effect did not decrease after controlling
for the change in PA (step 1, for condition ¼0.27,
p¼0.013; step 2 ¼0.31, p¼0.019). In contrast, the
decrease in SPT-neg appeared to be mediated by the
change in PA after the BPS manipulation. The pre- to
post-manipulation change in PA was significantly
associated with the change in SPT-neg (¼0.27,
p¼0.03), and the of the condition effect decreased
from 0.26 ( p¼0.018) in the first step to 0.12
(p¼0.354) after controlling for the change in PA.
The Sobel test ( p¼0.045) indicated that the indirect
effect of condition on the decrease in SPT-neg is
effectuated through the change in PA.
Moderation effects
In order to test whether the effects of the manipulation
were moderated by baseline dispositional optimism,
neuroticism or extraversion, we conducted a hierarchi-
cal regression analyses with the trait characteristic
(optimism, neuroticism or extraversion) and condition
as independent variables in the first step, their inter-
action in the second step and the pre- to post-
manipulation changes in PA, SPT-pos and SPT-neg
as dependent variables. For each dependent variable,
three regression models were specified, i.e. for each of
the trait characteristics separately.
The effect of the manipulation on PA was not
moderated by any of the trait characteristics, i.e. the
interaction terms did not reach significance. This
means that the effectiveness of the BPS manipulation
to increase PA did not depend on the baseline level of
optimism, neuroticism or extraversion of participants.
The change in SPT-pos was not moderated by any of
the trait variables; however, we did find a main effect
of trait optimism on the pre- to post-manipulation
Table 2. Pre- and post-manipulation scores for PA, NA and expectancies for positive and negative outcomes.
BPS condition
Mean (SD)
Control condition
Mean (SD)
Significant
effects
Effect
size
2
PA
Pre-intervention 2.51 (0.74) 2.55 (0.72) Time effect F(1, 78) ¼25.2, p50.001 0.19
Post-intervention 3.46 (0.74) 2.52 (0.93) Time group effect F(1,78) ¼27.6, p50.001 0.21
NA
Pre-intervention 1.48 (0.46) 1.50 (0.63) Time effect F(1, 78) ¼14.1, p50.001 0.15
Post-intervention 1.25 (0.33) 1.29 (0.36)
Positive expectancies
Pre-intervention 5.49 (0.71) 5.40 (0.68) Time group effect F(1, 79) ¼6.41, p¼0.013 0.07
Post-intervention 5.71 (0.67) 5.33 (0.68)
Negative expectancies
Pre-intervention 3.22 (1.05) 2.96 (0.83) Time effect F(1, 79) ¼65.5, p50.001 0.45
Post-intervention 2.59 (0.90) 2.62 (0.79) Time group effect F(1, 78) ¼5.82, P¼0.018 0.04
208 M.L. Peters et al.
Downloaded By: [Peters, Madelon L.] At: 15:20 25 June 2010
change in SPT-pos. The higher the level of baseline
optimism the lesser the increase in expectancies for
positive outcomes, after both manipulations. This may
be attributed to a ceiling effect: high optimists started
out with high scores on SPT-pos to begin with, leaving
little room for increases. The change in SPT-neg after
the manipulation was moderated by neuroticism.
Participants high in neuroticism profited more from
the BPS manipulation than participants low in neu-
roticism (Figure 1).
Finally, we examined whether the manipulation
effect on any of the outcome variables was moderated
by the quality and vividness of imagery. This appeared
not to be the case.
Discussion
This study tested a BPS writing and imagery exercise as
a means to increase optimistic future thinking. The
effectiveness of this manipulation was compared to a
control manipulation, writing about and imagining a
typical day. The BPS manipulation effectively influ-
enced mood and, importantly, also expectancies for the
future. PA was significantly higher after the BPS
manipulation than after the control manipulation
and expectancies for the future became more positive
(i.e. expectancies for positive outcomes and expectan-
cies for negative outcomes). The effects of the BPS
manipulation on positive future expectancies appeared
to be independent from its effects on positive mood.
In addition, the BPS manipulation appeared to be
equally effective for participants scoring high or low on
dispositional optimism and extraversion. However,
high neurotic participants seemed to have profited
most from the BPS manipulation, as demonstrated
by a greater reduction in negative future thinking.
One of the challenges we faced when designing this
study was to find an instrument that would allow us to
measure expectations for the future pre- and post-
manipulation, and that would be sensitive to tempo-
rary changes. Existing optimism instruments, such as
the LOT measure stable expectancies (e.g. with state-
ments containing phrases like ‘in general, ...’or
‘I always ...’) cannot be expected to be sensitive to
the effects of a short manipulation. On the other hand,
the instrument does have to be global, encompassing
various life domains, and refer to outcomes in the
future that have a certain degree of uncertainty.
Moreover, to distinguish optimism from self-efficacy,
the future outcomes referred to should be at least
partly devoid of voluntary control by the respondent.
The SPT seemed to meet these requirements. It assesses
how probable participants judge the occurrence of a
wide range of future outcomes, both positive and
negative, and encompassing various life domains
(health, social relations and career). The results of
this study indicated that especially expectancies for
positive future outcomes are related to dispositional
optimism as measured with the LOT. Moreover, in
another (unpublished) study in which we administered
the SPT and the LOT to 245 participants, we found
substantial correlations between both positive and
negative future expectancies and dispositional opti-
mism, i.e. Pearson r¼0.74 for positive expectancies
and r¼0.58 for negative expectancies. Therefore, we
propose that the SPT – and especially the positive
items – can indeed be considered an appropriate
instrument to measure optimistic future thinking.
The fact that BPS manipulation did not only affect
PA but also future expectancies as measured by the
SPT suggests that it is more than a mood manipula-
tion, and may indeed be considered as a manipulation
to induce optimism. Moreover, the expectancy effects
appeared to be independent from the mood effects, i.e.
the increase in expectancies for positive outcomes after
the BPS manipulation remained significant after con-
trolling for the increase in PA. The decrease in
expectancies for negative outcomes on the other hand
did appear to depend on the increase in positive mood.
This finding, together with the facts that (1) the largest
decrease in expectancies of negative outcomes was due
to a time effect and (2) the BPS effect on negative
expectancies only occurred in high neurotic individuals
suggests that different underlying mechanisms may be
responsible for the change in positive versus negative
expectancies. Especially, expectancies for positive out-
comes may reflect an optimistic thinking style. This is
consistent with the finding that at baseline, only
expectancies for positive outcomes and not negative
outcomes were related to dispositional optimism.
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Low Middle High
Neuroticism
Decrease in SPT-neg
BPS
Control
Figure 1. Neuroticism condition interaction on predic-
tion of decrease in expectancies for negative outcomes
(SPT-neg). Participants with high neuroticism benefit-
ted more from the BPS manipulation than participants
with low neuroticism (DSPT-neg ¼0.38 þ0.078 neuroti-
cism; p¼0.023). Neuroticism did not moderate the effect
of the control condition (DSPT-neg ¼0.400.015 neuroti-
cism; p¼0.045).
The Journal of Positive Psychology 209
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We did not find a difference between the conditions
on our two direct optimism questions. It may be
proposed that because these two questions were only
administered post-manipulation, the a priori variation
between participants in their expectancies masked
eventual changes induced by the manipulation.
Indeed, the question ‘how do you feel right now
about your future?’ correlated moderately with base-
line LOT (Pearson r¼0.23, p¼0.036). Administering
these direct questions pre- and post-manipulation
possibly would have increased the sensitivity.
The finding that compared to the control manip-
ulation, the BPS manipulation led to a larger increase
in PA but not to a larger decrease in NA is consistent
with the previous literature. Sheldon and Lyubomirsky
(2006) compared the effects of a BPS condition, a
gratitude condition (writing and thinking about the
things you are grateful for) and a control condition on
PA and NA. Similar to this study, the BPS and the
gratitude exercises increased PA more than the control
exercise whereas all three exercises decreased NA.
Burton and King (2004) also found that post-
manipulation PA was significantly higher after writing
about intense positive experiences compared to control
writing, whereas there were no changes in NA.
Why should thinking about a positive future lead
to changes in optimism? According to the expectancy –
value model of motivation as formulated by Carver
and Scheier (2001) – progress towards a goal deter-
mines affect and confidence of a good outcome. The
higher the rate of progress towards a goal, the more PA
an individual will experience and the higher his/her
optimistic outcome assessment. Mental simulation of a
positive scenario is proposed to have the same effect as
actual behaviour and therefore may similarly lead to
increased levels of confidence for success (Carver &
Scheier, 2001). These results support the idea.
Moreover, they also suggest that the impact of goal
progress on outcome expectancies is relatively inde-
pendent from the affective changes it generates. Thus,
even though affect and expectancy are both shifted into
a more positive direction, the change in one of them
does not necessarily mediate the change in the other.
It should be stressed that we have only looked at the
immediate effects of the BPS manipulation. This study
was meant as an initial exploration whether BPS writing
supplemented with a 5-min mental imagery component
would be able to increase optimistic thinking. Now that
we have found evidence that this manipulation may
indeed shift expectancies for the future into a more
positive direction, we are currently examining whether
repeated BPS imagery, practised in daily life, can lead to
more enduring changes in optimism. It is important
to note here that our endeavour to develop an
optimism manipulation is primarily motivated by its
scientific relevance, in that it will allow studying
the mechanisms of optimism more thoroughly.
The availability of a simple but effective manipulation
that can (temporarily) increase optimistic thinking
provides researchers with a tool that allows studying
the causal effect of optimism on a range of outcomes
(e.g. behavioural outcomes, such as persistence or
flexibility of behaviour, physiological outcomes, such
as stress reactivity or recovery).
Whether it is feasible to lastingly change disposi-
tional optimism is open to debate. Optimism is thought
to be at least partly genetically determined and further
shaped by early childhood experiences (Carver &
Scheier, 2005). It can be proposed that for a more
lasting effect, one would need to experience actual
positive outcomes instead of only imagining a positive
scenario because the former would entail actual rein-
forcement and thereby learning. It should also be
noted that some have cautioned against the potential
risk of increasing optimism (Norem & Chang, 2001).
Trying to increase optimism in people who are already
unrealistically optimistic could have deleterious effects
on outcome (e.g. increasing risk-taking behaviour).
Several limitations of this study should be men-
tioned. Although the effect of the BPS manipulation
on PA was quite large (
2
¼0.21 for the time condi-
tion interaction;
2
40.14 are considered large), its
effect on positive expectancies was only moderate
(
2
¼0.07). Future research should examine whether
the effects on expectancy can be enhanced when
the manipulation is extended, i.e. instead of a single
writing and imagery session, repeated sessions are
offered. If the BPS visualization systematically tar-
gets different life domains, people may come to see
themselves as globally successful persons (cf. Riskind
et al., 1996).
Another limitation is that we measured optimism
by means of a set of specific future expectancies
(i.e. with the SPT). There may be some similarities
between the content of the BPS visualization and the
expectancies measured by this instrument. Future
studies could use a more global measure of optimism.
Moreover, we only used direct and explicit measures of
affect and expectancies, and therefore we cannot rule
out that demand or expectations played a role.
We tried to control for that by giving the same
instructions in both conditions, with a similar sugges-
tion that writing and imagery could influence thoughts
and feelings. Nevertheless, due to the nature of the
manipulation, the BPS may have led to stronger
expectations of change. It would be interesting to use
more indirect assessment methods, e.g. an implicit
measure of optimism or behavioural or physiological
correlates of optimism.
In conclusion, this study provides evidence for the
efficacy of a BPS manipulation to temporarily enhance
optimism. In addition to a more positive mood, a
BPS manipulation changed the expectancies of partic-
ipants for the future in a more positive direction.
210 M.L. Peters et al.
Downloaded By: [Peters, Madelon L.] At: 15:20 25 June 2010
These results are encouraging and we are currently
examining longer term effects and the effects of a BPS
manipulation on indirect measures of optimism. The
BPS manipulation may be a suitable tool to study the
causal relations between optimism and psychological
and physical health.
References
Andersson, G. (1996). The benefits of optimism: A meta-
analytic review of the life orientation test. Personality and
Individual Differences, 21, 719–725.
Austenfeld, J.L., Paolo, A.M., & Stanton, A.L. (2006).
Effects of writing about emotions versus goals on psycho-
logical and physical health among third-year medical
students. Journal of Personality, 74, 267–286.
Burton, C.M., & King, L.A. (2004). The health benefits
of writing about intensely positive experiences. Journal of
Research in Personality, 38, 150–163.
Carver, C.S., & Scheier, M.F. (2001). Optimism, pessimism
and self-regulation. In E.C. Chang (Ed.), Optimism and
pessimism: Implications for theory, research, and practice
(pp. 31–52). Washington, DC: APA.
Carver, C.S., & Scheier, M.F. (2005). Optimism.
In C.R. Snyder & S.J.E. Lopez (Eds.), Handbook of
positive psychology (pp. 231–243). New York: Oxford
University Press.
Eysenck, H.J., & Eysenck, S.B.G. (1991). Manual of the
Eysenck personality scales (EPS adult). London: Hodder
& Stoughton.
Gillham, J.E., Reivich, K.J., Jaycox, L.H., & Seligman,
M.E.P. (1995). Prevention of depressive symptoms in
schoolchildren: Two-year follow-up. Psychological
Science, 6, 343–351.
Giltay, E.J., Kamphuis, M.H., Kalmijn, S., Zitman, F.G., &
Kromhout, D. (2006). Dispositional optimism and the risk
of cardiovascular death: The Zutphen elderly study.
Archives of Internal Medicine, 166, 431–436.
Harrist, S., Carlozzi, B.L., McGovern, A.R., & Harrist,
A.W. (2007). Benefits of expressive writing and expressive
talking about life goals. Journal of Research in Personality,
41, 923–930.
Holmes, E.A, Lang, T.J., & Shah, D.M. (2009). Developing
interpretation bias modification as a ‘cognitive vaccine’ for
depressed mood: Imagining positive events makes you feel
better than thinking about them verbally. Journal of
Abnormal Psychology, 118, 76–88.
Holmes, E.A., Mathews, A., Mackintosh, B., & Dalgleish, T.
(2008). The causal effect of mental imagery on emotion
assessed using picture-word cues. Emotion, 8, 395–409.
King, L.A. (2001). The health benefits of writing about life
goals. Personality and Social Psychology Bulletin, 27,
798–807.
Kivima
¨ki, M., Vahtera, J., Elovainio, M., Helenius, H.,
Singh-Manoux, A., & Pentti, J. (2005). Optimism and
pessimism as predictors of change in health after death or
onset of severe illness in family. Health Psychology, 24,
413–421.
Mackinnon, A., Jorm, A.F., Christensen, H., Korten, A.E.,
Jacomb, P.A., & Rodgers, B. (1999). A short form of the
Positive and Negative affect Schedule: Evaluation of
factorial validity and invariance across demographic
variables in a community sample. Personality and
Individual Differences, 27, 405–416.
MacLeod, A.K. (1996). Affect, emotional disorder, and
future-directed thinking. Cognition & Emotion, 10, 69–86.
Mahler, H.I.M., & Kulik, J.A. (2000). Optimism, pessimism
and recovery from coronary bypass surgery: Prediction of
affect, pain and functional status. Psychology, Health and
Medicine, 5, 347–358.
Norem, J.K., & Chang, E.C. (2001). A very full glass: Adding
complexity to our thinking about the implications and
applications of optimism and pessimism research.
In E.C. Chang (Ed.), Optimism and pessimism
(pp. 347–367). Washington, DC: APA.
Peters, M.L., Sommer, M., de Rijke, J.M., Kessels, F.,
Heineman, E., Patijn, J., et al. (2007). Somatic and
psychologic predictors of long-term unfavorable outcome
after surgical intervention. Annals of Surgery, 245,
487–494.
Quayle, D., Dzuirawiec, S., Roberts, C., Kane, R., &
Ebsworthy, G. (2001). The effect of an optimism and
lifeskills program on depressive symptoms in preadoles-
cence. Behaviour Change, 18, 194–203.
Riskind, J.H., Sarampote, C.S., & Mercier, M.A. (1996). For
every malady a sovereign cure: Optimism training. Journal
of Cognitive Psychotherapy, 10, 105–117.
Robbins, A.S., Spence, J.T., & Clark, H. (1991).
Psychological determinants of health and performance:
The tangled web of desirable and undesirable character-
istics. Journal of Personality and Social Psychology, 61(5),
755–765.
Scheier, M.F., & Carver, C.S. (1985). Optimism, coping,
and health: Assessment and implications of generalized
outcome expectancies. Health Psychology, 4, 219–247.
Scheier, M.F., & Carver, C.S. (1992). Effects of optimism on
psychological and physical well-being: Theoretical over-
view and empirical update. Cognitive Therapy and
Research, 16, 201–228.
Scheier, M.F., Matthews, K.A., Owens, J.F., Schulz, R.,
Bridges, M.W., Magovern, S.G.J., et al. (1999).
Optimism and rehospitalization after coronary artery
bypass graft surgery. Archives of Internal Medicine, 159,
829–835.
Seligman, M.E.P. (1990). Learned optimism. New York:
Knopf.
Sheldon, K.M., & Lyubomirsky, S. (2006). How to increase
and sustain positive emotion: The effects of expressing
gratitude and visualizing best possible selves. The Journal
of Positive Psychology, 1, 73–82.
Smith, T.W., Pope, M.K., Rhodewalt, F., & Poulton, J.L.
(1989). Optimism, neuroticism, coping, and symptom
reports: An alternative interpretation of the life orienta-
tion test. Journal of Personality and Social Psychology,
56, 640–648.
Wrosch, C., & Scheier, M.F. (2003). Personality and quality
of life: The importance of optimism and goal adjustment.
Quality of Life Research, 1, 59–72.
The Journal of Positive Psychology 211
Downloaded By: [Peters, Madelon L.] At: 15:20 25 June 2010
