An experimental investigation of thought suppression

An experiment investigating the hypothesis that trying to suppress a thought will lead to an immediate and/or delayed increase in its occurrence is reported. Normal subjects listened to a taped story and then verbalized their stream of consciousness during two consecutive time periods. During the first period, one group (suppression) were asked not to think about the tape while two other groups (controls) were asked to think about anything or think about anything including the tape. During the second period, all three groups were instructed to think about anything. Results from the first period failed to support the immediate enhancement hypothesis as the suppression group reported less thoughts about the tape than the controls. However, results from the second period supported the delayed (rebound) hypothesis as subjects who had previously suppressed reported more thoughts about the tape than subjects who had not. The theoretical, methodological, and clinical implications of these results are discussed.     

Summoning White Bears or Letting Them Free: The Influence of the Content of Control Instructions on Target Thought Frequency

In the clinical literature, thought suppression is considered to play a role in the development of intrusion-related psychiatric syndromes, such as obsessive-compulsive disorder, acute or posttraumatic stress disorder, phobias, and addiction. This assumption goes back to a study by D. M. Wegner, D. J. Schneider, S. R. Carter, and T. L. White (1987) in which participants were asked to suppress thoughts of a white bear, an assignment that proved to be nearly impossible to complete. The present two studies sought to explore the influence of the content of control instructions on intrusion frequency in thought suppression experiments. Notably, during nonsuppression (i.e., control) periods, participants can either be instructed to think about white bears (i.e., expression instruction), or to think of anything including white bears (i.e., liberal instruction). Results indicated that expression instructions resulted in an increased number of target thoughts, while liberal instructions did not. Implications for the interpretation of thought suppression findings are discussed.     

The suppression of exciting thoughts

We examined how the suppression of an exciting thought influences sympathetic arousal as indexed by skin conductance level (SCL). Subjects were asked to think aloud as they followed instructions to think about or not to think about various topics. Experiment 1 showed that trying not to think about sex, like thinking about sex, elevates SCL in comparison to thinking about or not thinking about less exciting topics (e.g., dancing). Experiment 2 revealed that the suppression of the thought of sex yielded SCL elevation whether or not subjects believed their think-aloud reports would be private or public, and it also revealed that the effect dissipated over the course of a few minutes. Experiment 3 found such dissipation again but showed that subsequent intrusions of the suppressed exciting thought are associated with further elevations in SCL over 30 min. Because such an association was not found when subjects were trying to think about the exciting thought, it was suggested that the suppression of exciting thoughts might be involved in the production of chronic emotional responses such as phobias and obsessive preoccupations.     

Setting free the bears: escape from thought suppression

A person who is asked to think aloud while trying not to think about a white bear will typically mention the bear once a minute. So how can people suppress unwanted thoughts? This article examines a series of indirect thought suppression techniques and therapies that have been explored for their efficacy as remedies for unwanted thoughts of all kinds and that offer some potential as means for effective suppression. The strategies that have some promise include focused distraction, stress and load avoidance, thought postponement, exposure and paradoxical approaches, acceptance and commitment, meditation, mindfulness, focused breathing, attention training, self-affirmation, hypnosis, and disclosure and writing. Many of these strategies entail thinking about and accepting unwanted thoughts rather than suppressing them--and so, setting free the bears. (PsycINFO Database Record (c) 2011 APA, all rights reserved).     

Effects of suppressing neutral and obsession-like thoughts in normal subjects: beyond frequency

Recent cognitive-behavioral theories on obsessive-compulsive disorder (OCD) show that deliberate attempts to suppress intrusive and undesirable thoughts lie at the genesis of clinical obsessions. In this paper the results of an experimental study on the suppression of neutral and obsession-like thoughts in normal subjects are presented. Eighty-seven university students performed in three experimental periods: (1) base-line monitoring, (2) experimental instruction, and (3) monitoring. For each of these periods, the frequency of the occurrence of a "white bear" thought or a personally relevant intrusive thought was registered. Half of the subjects received instructions to suppress the target-thought in period 2, and the other half were instructed to only monitor the target-thought in each of the experimental periods. Several measures were also obtained before and after the experiment: annoyance caused by the intrusion, suppression effort, subjective success, and evaluative appraisals of the target-thought. The results showed neither immediate nor delayed frequency increases of the target thought. However, evidence was found that deliberate thought suppression efforts, regardless of their content, had greater negative consequences than did non suppression. These results are discussed in relation to the recent cognitive proposals about OCD.     

On bad mood and white bears: The effects of mood state on ability to suppress unwanted thoughts

Does temporary mood influence people's ability to engage in effective thought suppression? Based on past research on mental control and recent work on affective influences on social cognition, this experiment predicted and found that negative mood improved and positive mood impaired people's ability to suppress their thoughts when instructed not to think of a neutral concept, white bears. We also found clear evidence for ironic rebound effects: on a subsequent generative task, intrusions of the suppressed thought were greater in the negative than in the positive mood group. Participants received positive or negative feedback about performance on a supposed creativity task to induce positive or negative moods, and then engaged in two consecutive generative writing tasks, the first accompanied by instructions to suppress thoughts of white bears. Those in a negative group reported fewer “white bear” intrusions when attempting to suppress, but more “white bear” intrusions (an ironic rebound effect) in the subsequent task when the suppression instruction was lifted. The implications of these results for everyday tasks of mental control, and for recent affect–cognition theories are discussed.     

Effect on Mood of Thinking About Extreme Emotional Terms

The hypothesis that being asked to think about extreme emotional terms influences mood in the direction of the polarity of the terms was tested in three experiments. Subjects answered items about their mood before and after being asked to think about nine extreme, positive emotional terms (e.g., ecstatic) or nine extreme, negative emotional terms (e.g., wretched). It was found that when subjects were asked to think about extreme, positive emotional terms, mood changed in a positive direction, and when they were asked to think about extreme negative emotional terms, mood changed in a negative direction. The effect on mood of being asked to think about extreme emotional terms did not depend on whether the subjects were asked just to think about the terms(Experiment 1), to think about the terms in relation to the self (Experiment 2), or to think about the meaning of the terms (Experiment 3).     

Personally relevant intrusions outside the laboratory: Long-term suppression increases intrusion

It has been suggested that the suppression of unwanted thoughts may increase their frequency and that this effect may contribute to some psychological problems. Previous studies have examined this over a period of minutes, in an artificial setting. Suppression over a four day period was evaluated in the present study. Each S was asked to identify a negative intrusive thought which he or she experienced and to record each occurrence of it in conditions designed to maximise the similarity to those experienced by obsessional patients. Ss were randomly allocated to one of three groups. One group was asked to suppress their thoughts whenever they occurred, another group was asked to think about their thoughts whenever they occurred and the third group just recorded the thoughts whenever they occurred. This design allowed experimental control of both attention to and manipulation of the target thoughts in contrast to attention and active suppression. It was found that Ss who suppressed their thoughts experienced more thoughts and found them more uncomfortable than Ss in the other two groups. This is consistent with the theory that suppression increases thought frequency and may be important in the development and maintenance of some disorders.     

Suppression of novel stimuli: Changes in accessibility of suppressed nonverbalizable shapes

Recently, a new method of considering successful intentional thought suppression has emerged. This method, the think/no-think (TNT) paradigm has been utilized over a multitude of settings and has fairly robustly demonstrated the ability to interfere with memory recall. The following experiment examined the effect of intentional thought suppression on recognition memory of nonverbalizeable shapes. In this experiment, participants learned word-shape targets. For some of the pairs, they rehearsed the shape when presented with the word; for others, they suppressed the shape when presented with the word. Finally, participants were shown multiple shapes, one at a time, and asked to identify which they had previously seen as paired with a word. Results of the experiment indicated that, similar to results involving words, participants were less accurate in identifying suppressed shapes, as compared to rehearsed shapes. Implications of these findings are discussed.     

Failures to find suppression of episodic memories in the think/no-think paradigm

Anderson and Green (2001) had subjects learn paired associates and then selectively suppress responses to some of them. They reported a decrease in final cued recall for responses that subjectshad been instructed not to think of and explained their data as resulting from cognitive suppression, a laboratory analog of repression. We report three experiments designed to replicate the suppression/repression results. After subjects learned a series of A-B word pairs (e.g., ordsea-roach), they were then asked to respond to some items and not to think of other items when shown their cues 1, 8, or 16times. During a final recall test, they were cued with either asame (direct)probe (ordeal-__) or a n independent(indirect) probe (insect-r__) . None of our experiments showed reliable suppression effects with either the same or independent-probe tests. Suppression is apparently not a robust experimental phenomenon in the think/no-think paradigm.     

Suppression and Repression to Discrepant Self-Other Ratings: Relations with Thought Control and Cardiovascular Reactivity

ABSTRACT Individual differences in self-other disagreement may lap phenomena that have been notoriously difficult to assess. For example, subjects who believe they possess a trait while their acquaintances disagree may be exhibiting suppression. Further, subjects who deny a trait while acquaintances believe it is present may be displaying repression. In the first study, both subjects and their closest friends rated the subject's hostility level. Suppressors and repressors were expected to exhibit enhanced thought control, and indeed these individuals were more able not to think about white bears when instructed to do so than individuals for whom there was high hostility agreement. However, this was also true for those with low hostility agreement. Only suppressors demonstrated blood-pressure hyperreactivity to a hostility-provoking task as expected; this finding was replicated in a second study employing a different, multi-item measure of hostility, as well as a marker of low Agreeableness.     

Suppressing and attending to pain-related thoughts in chronic pain patients

Attempted suppression of pain-related thoughts was investigated in consecutive referrals for pain management (N = 39). Participants monitored their pain-related thoughts for three 5-min periods. In period 1, all participants were instructed to think about anything. For period 2, participants were instructed to either suppress pain-related thoughts, attend to pain-related thoughts, or to continue to think about anything. In period 3, all participants were again instructed to think about anything. Participants instructed to attend to their pain reported more pain-related thoughts than suppressors and controls in both periods 2 and 3. Suppressors experienced reduced pain-related thoughts during period 2. There was no immediate enhancement or delayed increase.     

The Duty to Support Nationalistic Policies

We demonstrate that citizens perceive a duty to support policies that benefit their nation, even when they themselves judge that the consequences of the policies will be worse on the whole, taking outsiders into account. In terms of actions, subjects think they would do their perceived duty rather than violate it for the sake of better consequences. The discrepancy between duty and judged consequences does not seem to result from self‐interest alone. When asked for reasons, many subjects felt an obligation to help their fellow citizens before others, and they also thought that they owed something to their nation, in return for what it did for them. The obligation to help fellow citizens was the strongest predictor of perceived duty. In an experiment with Israeli and Palestinian students, group membership affected both perceived overall consequences and duty, but the effect of group on perceived consequences did not account for the effect on perceived duty. Copyright © 2011 John Wiley & Sons, Ltd.     

Obsessive–compulsive symptoms, white noise and intrusions of self–relevant negative thoughts in a thought suppression paradigm

Forty female students participated in an experiment where they were asked to suppress a negative self-relevant thought. Half the group suppressed in a loud white noise condition (90 decibels) whereas the other half suppressed in a noise condition of much lower intensity (50 decibels). The subjects were divided up into two groups on the basis of their scores on the Obsessive Compulsive Thoughts Checklist (Bouvard, Cottraux, Mollard, Arthus, Lachance, Guerin, Sauteraud & Yao, 1997). It was predicted that 1) Subjects scoring high on obsessive-compulsive symptoms would show more intrusive thoughts 2) Loud noise would increase intrusive thoughts, especially for subjects scoring high on obsessive-compulsive symptoms. As expected subjects who scored high on obsessive-compulsive symptoms showed more intrusive thoughts, but contrary to expectations loud noise did not increase intrusive thoughts. In fact obsessive-compulsive symptoms were related to more intrusions in the condition of noise of less intensity but not in the condition of loud noise. Implications are discussed.     

Does language shape thought? Mandarin and English speakers' conceptions of time

Does the language you speak affect how you think about the world? This question is taken up in three experiments. English and Mandarin talk about time differently--English predominantly talks about time as if it were horizontal, while Mandarin also commonly describes time as vertical. This difference between the two languages is reflected in the way their speakers think about time. In one study, Mandarin speakers tended to think about time vertically even when they were thinking for English (Mandarin speakers were faster to confirm that March comes earlier than April if they had just seen a vertical array of objects than if they had just seen a horizontal array, and the reverse was true for English speakers). Another study showed that the extent to which Mandarin-English bilinguals think about time vertically is related to how old they were when they first began to learn English. In another experiment native English speakers were taught to talk about time using vertical spatial terms in a way similar to Mandarin. On a subsequent test, this group of English speakers showed the same bias to think about time vertically as was observed with Mandarin speakers. It is concluded that (1) language is a powerful tool in shaping thought about abstract domains and (2) one's native language plays an important role in shaping habitual thought (e.g., how one tends to think about time) but does not entirely determine one's thinking in the strong Whorfian sense.     

Thought suppression and its effects on thought frequency, appraisal and mood state in individuals with obsessive-compulsive disorder

Leading models of obsessive-compulsive disorder (OCD) implicate thought suppression as a key factor in the escalation and persistence of the disorder. This experiment examined the effects of suppression on the frequency of obsessional thoughts in 50 individuals with a primary diagnosis of OCD, and also investigated the effects of participants' appraisals regarding their failures in thought control on distress about intrusive thoughts and on mood. Participants' most upsetting obsessional thought was primed and they then monitored its occurrence over two 4-min intervals. In the first interval, half of the participants were instructed to suppress their obsessional thought and half were instructed not to suppress any thoughts. In the second interval, all participants were given the 'Do Not Suppress' instructions. Participants rated their suppression effort and discomfort over thought occurrences after each interval and recorded their appraisals of thought recurrences during the first interval. Mood state was then reassessed. No ironic effect of suppression on frequency was noted. However, negative appraisals of thought recurrences were associated with more discomfort over thought occurrences and more negative mood at Time 2. These findings suggest that interpretations regarding failures in thought control may be of central importance in understanding obsessional problems.     

Attention as a predictor of learning in infants

A total of 240 fourteen-week-olds were rewarded with a pattern of lights and tones for kicking. The reward display interrupted a background of random alternation between two lights and tones. In experiment 1, attention to this background stimulus during a 1-min baseline was assessed using the number of fixations of alternating lights. During 6 min of reward, high-attention subjects showed significantly greater changes in kicking rate from baseline than low-attention subjects. In experiment 2, the proportion of subjects with low attention ratings increased dramatically during an extended 5-min baseline period, and those subjects with low attention ratings at the end of baseline did not show an increase in kicking from baseline to the reward phase, while high-attention subjects did show evidence of learning. Thus, an objective measure of attention, empirically separate from the dependent learning measure, provided a significant prediction of the effectiveness of subsequent reinforcement, and could be manipulated simply by extending the baseline by as little as 4 min.     

Misleading postevent information: Testing parameterized models of integration in memory

A classic series of experiments by Loftus, Miller and Burns (1978) showed that a person's recollection of an event can be changed by misleading postevent information. Several hypotheses accounting for this effect have been proposed. Loftus' hypothesis of destructive updating claims that the original memory is destroyed by the postevent information. The coexistence hypothesis asserts that the older memory survives but is rendered inaccessible through a mechanism of inhibition or suppression. The non-conflict hypothesis simply accounts for the effect by claiming that subjects can only be misled if they did not encode or if they forgot the original event. These three hypotheses were modelled with the help of all-or-none probabilistic event trees. An experiment was conducted in order to test the three models and to assess parameter values. The experiment followed the classic Loftus paradigm. We suggested to some subjects that they had seen a stopsign, whereas in fact they had seen a traffic light. The misleading postevent information resulted in poorer reproduction of traffic light. Later, all subjects were asked whether they could remember the color of the traffic light, even if they believed they had seen a stopsign. The results showed that subjects who received the misleading post-event information were at least as good at recalling the color of the traffic light as subjects who did not receive misleading information. The no-conflict model accounts well for the obtained results, although the two other, less parsimonious, models cannot be entirely rejected.     

Self-report may underestimate trauma intrusions

Research examining maladaptive responses to trauma routinely relies on spontaneous self-report to index intrusive thoughts, which assumes people accurately recognize and report their intrusive thoughts. However, “mind-wandering” research reveals people are not always meta-aware of their thought content: they often fail to notice shifts in their attention. In two experiments, we exposed subjects to trauma films, then instructed them to report intrusive thoughts during an unrelated reading task. Intermittently, we asked whether they were thinking about the trauma. As expected, subjects often spontaneously reported intrusive thoughts. However, they were also “caught” engaging in unreported trauma-oriented thoughts. The presence and frequency of intermittent probes did not influence self-caught intrusions. Both self-caught and probe-caught intrusions were related to an existing tendency toward intrusive cognition, film-related distress, and thought suppression attempts. Our data suggest people may lack meta-awareness of trauma-related thoughts, which has implications for theory, research and treatment relating to trauma-related psychopathology.     

Attempting suppression of traumatic memories over extended periods in acute stress disorder

This study investigated the influence of attempted suppression and thought control strategies on traumatic memories. Survivors of civilian trauma with acute stress disorder (ASD; n = 20) and without ASD (n = 20) monitored their trauma-related thoughts for three 24-h periods. In period 1, participants were instructed to think about anything. In period 2, participants were administered suppression or nonsuppression instructions relating to thoughts of the trauma. In period 3, participants were again instructed to think about anything. The results revealed no evidence for an increase in trauma-related thoughts following suppression instructions. Punishment and worry thought control strategies correlated significantly with both anxiety and suppression ratings. Frequency of intrusions was associated with a distraction cognitive strategy. These findings point to the importance of traumatised individuals' cognitive strategies in mediating the management and occurrence of posttraumatic intrusions.