Undoing Hypothesis: How Positive Emotions Counteract Stress

Strong emotions, such as anger and fear, coincides with the activation of the sympathetic nervous system, motivating adaptive survival activity. Along with anger and fear, our heart rates increase, our blood pressure rises, ​glycogenolysis (breaking down glucose to create immediate energy) ensues, gastrointestinal peristalsis (a normal digestive function) ceases. When the sympathetic nervous system is activated, almost every living tissue of our body is awakened and prepared for action. In Barbara Fredrickson’s Undoing Effect theory, she proposes that positive emotions counteract the arousal, bringing the body back into healthy functioning states.

Activation of the sympathetic nervous system is the “nonspecific response of the body to any demand” (Tan & Yip, 2018). Hans Selye, known for his work on stress, wrote that, “Stress is an interaction between damage and defense.” He explains that the physiological response to stress has “toxic effects” (Selye, 1951). Physiological arousal to combat threats to our wellbeing is necessary for survival but comes at a cost.

Some researchers theorize that certain positive emotions play an essential role in “undoing” the physiological arousal caused by negative emotions. One of the functions, they suggest, of positive emotions “is to facilitate tension reduction” (Yuan, et al., 2010).

Silvan Solomon Tompkins (1911-1991), in reference to the stress-response, referred to “the-smiling-joy response” as a reaction to the decreases in the density of stimulation, or neural arousal, that accompanies strong emotion (Tompkins, 2010). According to Tompkins, the reduction of stress causes the smile.

The undoing effect theory suggests that the smile relieves the tension. In other words, positive emotions put the brakes on the sympathetic nervous system by hastening a return to homeostasis by “undoing, or down-regulating, of physiological arousal caused by negative emotions” (Tompkins, 2010. p. 467).

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Health and Positive Emotions

The undoing effect is a subcategory of research that falls under a much larger, and almost universally accepted theory—positive emotions promote health. Evidence strongly suggests that positive affect (experiencing positive emotions) is associated with “a reduced risk of developing cardiovascular disease and is protective against the progression of cardiovascular disease” (Cavanagh & Larkin, 2018).

Positive emotions have been theorized to promote healthy functioning that spans across social, cognitive, and physiological domains. Barbara Fredrickson theorizes that positive emotions open up new paths for development in her Broaden and Build theory. She explains, “These broadening mindsets carry indirect and long-term adaptive benefits because broadening builds enduring personal resources, which function as reserves to be drawn upon later to manage future threats” (Fredrickson, 2001).

In explaining the undoing effect, Fredrickson wrote: 

“If negative emotions narrow the momentary thought–action repertoire and positive emotions broaden this same repertoire, then positive emotions ought to function as efficient antidotes for the lingering effects of negative emotions” (Fredrickson, 2001). 

T. Franklin Murphy explains:

“The broadening of attention and stockpiling of resources contribute to wellbeing by improving future problem solving. We gather wisdom, build skills, and actively recover from demands” (Murphy, 2020).

Positive emotions is postulated to impact wellness across many plains and thus researchers are curious to uncovering the mechanisms behind positive emotions that may create the conditions that lead to health and wellness. Undoing effect is one of the theories seeking to explain why positive emotions improve health and promote overall wellness.

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History of Undoing Hypothesis Effect of Positive Emotions

As early as 1988, Robert W. Levenson suggested:

“The evolutionary meaning of positive emotions such as happiness might be to function as efficient ‘undoers’ of states of ANS arousal produced by certain negative emotions” (Levenson, 1988, p. 23).

The actual theory of undoing affect can be traced back to a 1998 publication of research conducted by Barbara Fredrickson and Levenson published in the Journal of Cognition and Emotion.

Fredrickson and Levenson present the undoing effect theory as: In there 1998 paper they presented two studies that utilized movies to stimulate the sympathetic nervous system response (fear and sadness) and then measured recovery time, assessing the impact of positive emotions on the speed of recovery. Fredrickson and Levenson’s findings supported the undoing effects hypothesis.

Action Tendencies and Emotion

An underlying concept essential to the undoing effect hypothesis is that negative affect evokes action tendencies (Murphy, 2025). “Negative emotions that create urges for specific action requiring substantial physical energy (e.g., attack, flee) also produce heightened cardiovascular reactivity that redistributes blood flow to relevant skeletal muscles” (Fredrickson et al., 2000). Action potentials typically focus on an environmental threat that demands specific behaviors to eliminate the threat. Our emotional responses, hence, are survival mechanisms to combat specific threats.

Positive emotions, on the other hand, are “often characterized by relative lack of autonomic reactivity” (Fredrickson et al., 2000, p. 238). The undoing effect hypothesis explains the survival benefits of positive emotions. Since they don’t elicit specific behavior through activation of the autonomic nervous system, what exactly do they do?

According to Fredrickson and Levenson, positive emotions have two primary purposes:

• First is the broadening effect. The broadening effect suggests that during positive emotions we gather enduring resources that contribute to resilience during more trying times.
• Second is the undoing effect. The undoing effect suggests that positive emotion states reset the body, bringing it back into a homeostatic balance.

Positive Emotions and Negative Emotions

In contrast to negative emotions, which promote survival in the moment by addressing specific threats with life preserving actions, positive emotions promote survival over the long run by building resources that could be drawn upon later. Positive emotions “can build a variety of enduring personal resources” (Fredrickson et al., 2000, p. 239). The second purpose is the regulating influence positive emotions have on arousal, down regulating the autonomic nervous system, returning to a physiological homeostasis. 

Negative affect floods the biological system with activating chemicals that evolved to prepare the body for threat. However, a prolonged, overabundance of those chemicals damages organs, leading do illness and disease. Murphy explains, “These physical changes have a cost, and when that cost exceeds our ability to process we become vulnerable to predispositioned diseases” (Murphy, 2021).

Selye explained that, the effects of stress “depend not only on the magnitude and duration of the stressor, but also on the strategies individuals adopt to cope with it” (Heller & LaPierre, 2012). The undoing effect is an unconscious mechanism that the body uses to reset biological levels by down regulating arousal through positive emotions.

Empirical Support for Undoing Effect

Early studies found substantial support for Levenson and Fredrickson’s undoing hypothesis. However , more recent studies throw some doubt on the theory. While positive emotions are empirically supported to be associated with health, the undoing effect may not be the cause for the association.

Many of the terms used in the early studies were broad and difficult to quantify. When researchers accounted for other confounding variables (resiliency, flourishing, appraisal style, etc.) only a few of the previous cited studies supported the undoing hypothesis. Most of the studies. “It is possible that these individual characteristics exert a more powerful effect on physiological recovery than state positive affect, which may explain why several studies either found partial support or failed to support the undoing hypothesis altogether” (Cavanagh & Larkin, 2018).

In a 2022 meta-analytic review of whether positive emotions facilitate autonomic nervous system recovery, the authors “found no support for the general undoing effect of positive emotions” (Behnke et al., 2022, p. 14).

Associated Concepts

• Broaden-and-Build Theory: This theory, proposed by Barbara Fredrickson, suggests that positive emotions broaden an individual’s momentary thought-action repertoire, which in turn builds their enduring personal resources, ranging from physical and intellectual resources to social and psychological ones.
• Resilience Theory: Resilience in psychology refers to the ability to cope with and bounce back from adversity. Positive emotions play a crucial role in resilience, helping individuals recover from stress and trauma.
• Emotion Regulation: This concept involves strategies people use to influence their own emotional experience. The undoing effect can be seen as a form of emotion regulation, where positive emotions help to down-regulate the negative emotions.
• Affective-Cognitive Consistency: This theory posits that when individuals experience positive emotions, their cognitive processes are more likely to be congruent with their affective states, leading to a more harmonious internal state.
• Positive Psychology Interventions: These interventions aim to increase well-being and happiness, often by leveraging the undoing effect to counterbalance negative emotions and enhance positive ones.
• Stress Recovery Theory: This theory suggests that positive emotions facilitate the recovery from the physiological effects of stress, aligning closely with the undoing effect.
• Opponent-Process Theory: Originally a theory of color vision, this has been applied to emotions as well, suggesting that an emotional experience can trigger its opposite, to restore emotional balance.

A Few Words by Psychology Fanatic

Research still supports the broader category of positive emotions and health. Whether positive emotions are a cause or symptom to health is still under investigation. Perhaps, there is an undoing effect. It just isn’t the sole cause for or purpose of positive emotion.

We know some protect against intense emotions with escape through “gallows humor,” or a healthy laugh while in the depths of sorrow. Somehow these mechanisms protect against realities that overwhelm our threshold to process, and potentially causing damage to our bodies. Certainly, we should continue to promote positive emotions even if we aren’t completely certain of the process behind them. Undoubtedly, resetting our bodies to healthier states will create better health and promote a greater senses of wellness.

Last Update: January 28, 2026

References:

Behnke, M., Pietruch, M., Chwiłkowska, P., Wessel, E., Kaczmarek, L., Assink, M., & Gross, J. (2022). The Undoing Effect of Positive Emotions: A Meta-Analytic Review. Emotion Review, OnlineFirst, 1. DOI: 10.1177/17540739221104457
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Cavanagh, C., & Larkin, K. (2018). A Critical Review of the “Undoing Hypothesis”: Do Positive Emotions Undo the Effects of Stress?. Applied Psychophysiology and Biofeedback, 43(4), 259-273. DOI: 10.1007/s10484-018-9412-6
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Fredrickson, B. L., & Levenson, R. (1998). Positive Emotions Speed Recovery from the Cardiovascular Sequelae of Negative Emotions. Cognition & Emotion, 12(2), 191-220. DOI:  10.1080/026999398379718
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Fredrickson, B. L., Mancuso, R. A., Branigan, C. and Tugade, M. M. (2000). The undoing effect of positive emotions. Motivation and Emotion 24, 237–258. DOI: 10.1023/A:1010796329158
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​Fredrickson, B. (2001). The role of positive emotions in positive Psychology. The broaden-and build theory of positive emotions. The American psychologist, 56(3), 218-226. DOI: 10.1037/0003-066X.56.3.218
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Levenson, R. W. (1988). Emotion and the autonomic nervous system: A prospectus for research on autonomic specificity. In H. L. Wagner (Ed.), Social psychophysiology and emotion: Theory and clinical applications (pp. 17–42). John Wiley & Sons.​ ISBN: 9780471912668; APA Record: 1988-97882-000
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Murphy, T. Franklin (2020). Broaden and Build Theory. Psychology Fanatic. Published: 9-4-2020; Accessed: 9-24-2022. Website: https://psychologyfanatic.com/broaden-and-build/
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Murphy, T. Franklin (2021) Diathesis Stress Model. Psychology Fanatic. Published: 9-7-2021; Accessed: 9-25-2022. Website: https://psychologyfanatic.com/diathesis-stress-model/
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Murphy, T. Franklin (2025). Action Tendencies: Understanding Emotional Responses. Psychology Fanatic. Published: 5-27-2025; Accessed: 5-27-2025. Website: https://psychologyfanatic.com/action-tendencies/
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Selye, Hans (1951). The General-Adaptation-Syndrome. Annual Review of Medicine, 2(1), 327-342. DOI: 10.1146/annurev.me.02.020151.001551
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​Tan, Siang Yong, Yip, A (2018) ​Hans Selye (1907–1982): Founder of the stress theory. DOI: 10.11622/smedj.2018043
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Tompkins, Michael A. (2013). Anxiety and Avoidance: A Universal Treatment for Anxiety, Panic, and Fear. ‎New Harbinger Publications. ISBN-10: 1608826694
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​Yuan, J., McCarthy, M., Holley, S., & Levenson, R. (2010). Physiological Down-Regulation and Positive Emotion in Marital Interaction. Emotion, 10(4), 467-474. DOI: 10.1037/a0018699
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