Daytime emotional suppression does not affect the emotional tone of dreams

People tend to experience fewer positive emotions and more negative emotions in their dreams than they do while awake. However, a person’s tendency to hide their feelings during the day does not seem to change the emotional intensity of their dreams. These findings were published in the journal Dreaming.

Sleep and memory researchers propose that dreaming serves as a nighttime emotional processing system. In this view, the sleeping brain uses dreams to integrate difficult memories and regulate psychological stress. This processing can sometimes create a rebound effect. When people actively ignore or repress thoughts during the day, those same thoughts often surface vividly in their dreams at night.

The psychological concept known as ironic process theory suggests that trying to suppress a thought requires the brain to constantly monitor for it. Because the brain’s executive control systems are less active during sleep, this monitoring process can backfire. The suppressed thoughts break through into dreams, often bringing intense negative emotions with them. Past research has shown that this rebound effect might be particularly strong for feelings of sadness, fear, and anger.

Because of this proposed processing function, the emotions people feel in their dreams do not always match the emotions they feel while awake. Previous investigations have noted an emotional disconnect, where waking life is generally more positive, but dream life is more negative.

Yui Yoshioka, a researcher at Kwansei Gakuin University who conducted the work at Kyoto University, wanted to understand if a specific psychological trait drives this disconnect. Yoshioka hypothesized that people who regularly suppress their emotions during the day would experience a sharper drop in positive dream emotions and a larger spike in negative dream emotions.

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To test these ideas, Yoshioka recruited participants online and screened them for severe depression and low dream recall. A total of 76 adults completed the full study. During the initial screening, the participants filled out questionnaires assessing their general habits regarding dreams and their tendency to suppress emotional expression. Based on these survey results, the researcher divided the participants into a high emotional suppression group and a low emotional suppression group.

The main part of the research involved a seven-day diary survey. Every evening before going to bed, participants rated the intensity of the emotions they had experienced that day. They scored four positive emotions, such as joy and satisfaction, and four negative emotions, such as sadness and anger, on an eight-point scale.

Every morning upon waking, the participants provided a detailed written description of any dreams they remembered. They then used the same eight-point scale to rate the emotions they felt within those dreams. The researcher averaged these daily scores to measure each person’s typical emotional experience during wakefulness and sleep.

The daily diary entries revealed a shift in emotional tone between waking and sleeping states. During the day, the participants reported experiencing positive emotions more intensely than negative emotions. In their dreams, however, the intensity of positive emotions like satisfaction and joy went down. At the same time, the intensity of negative emotions like anxiety and confusion went up.

This pattern aligned with the idea that dreams might prioritize the processing of negative psychological material. Despite this overall trend, the results did not support the hypothesis regarding emotional suppression. The data showed no differences in dream emotion intensity between the high emotional suppression group and the low emotional suppression group.

People who regularly hid their waking emotions did not experience more intense negative dreams or less intense positive dreams than those who expressed their feelings freely. The only difference found between the two groups was behavioral. Individuals with lower emotional suppression tendencies were simply more likely to talk about their dreams with other people.

Readers should keep in mind how emotional suppression was measured in this specific research context. The questionnaire used to categorize participants focused on the suppression of emotional expression, such as hiding irritation or remaining silent when angry. It did not measure the internal, unconscious repression of the feeling itself.

Participants in the high suppression group may have fully recognized their daytime emotions without actually trying to banish the thoughts from their minds. If they were only hiding their outward physical or verbal reactions, the anticipated dream rebound effect might not be triggered.

Cultural factors might also influence the emotional patterns observed in the data. The study was conducted with adults in Japan, where cultural norms often encourage restraint in emotional expression and self-disclosure. Because outward emotional suppression is relatively common in this context, the entire sample may have had a higher baseline for this trait.

This general cultural tendency could make it difficult to detect subtle variations between the high and low suppression groups. Additionally, participants might have unconsciously downplayed the intensity of negative feelings in their diaries. Because they knew a researcher would be reading their entries, social desirability bias could have altered their self-reported emotional ratings.

The method of recording dreams can alter which dreams are studied. A daily diary requires participants to write down whatever they remember each morning, even if the dream was mundane or emotionally flat. Other dream research methods ask participants to recall their single most impactful recent dream.

Those alternative methods tend to yield reports of stranger and more intensely negative dreams. Relying on a daily diary might capture an accurate average of nightly experiences, but it could miss the extreme emotional spikes that occur in occasional, highly memorable dreams.

Future studies could measure emotional responses more objectively. Relying on self-reported emotion ratings leaves room for memory biases, as people quickly forget the details of their dreams upon waking. Using physiological sensors to track emotional arousal during sleep could provide a more direct measure of what the brain is experiencing.

Researchers might also incorporate experimental tasks where participants are instructed to suppress specific thoughts before bed. This would allow for a more controlled test of the rebound effect, independent of a person’s general personality traits.

The study, “Emotional Suppression and the Relationship Between Wakeful and Dream Emotions,” was authored by Yui Yoshioka.