Decoding Emotions: An In-Depth Look at Schachter-Singer’s Two-Factor Theory

The two-factor theory of emotion, also known as the Schachter-Singer theory, offers a comprehensive perspective on the complex nature of human emotions. Proposed by researchers Stanley Schachter and Jerome Singer in the 1960s, this theory posits that emotions are the result of two factors: physiological arousal and cognitive interpretation.

One of the main differences between the Schachter-Singer theory of emotion and the earlier James Lange theory of emotion is that according to Schachter-Singer that, “The same visceral states occur in very different emotional states and in non-emotional states” (Schachter & Singer, 1962).

Basically, Schachter and Singer proposed that events arousal the sympathetic nervous system and then we label the arousal according to the context surrounding the arousal. This differs from the James-Lange theory because his cognitive label occurs after a behavioral reaction to the arousal, suggesting a difference in arousal states.

What are the Two Factors?

Physiological Arousal

According to the two-factor theory, when we experience an emotion, we first undergo a physiological arousal. This physiological response is often accompanied by the release of certain hormones and neurotransmitters in our bodies, leading to increased heart rate, sweaty palms, and other bodily sensations. However, physiological arousal is not emotion. In psychology, we often refer to this as feeling affects. Our biological system reacts to the environment. The arousal leads to a behavioral reaction to reduce the arousal. We sometimes refer to this in psychology as returning to a homeostatic balance.

Not all Physiological Arousal is an Emotion

Basically, a significant ingredient for the creation of emotion is physiological arousal. One of the significant proposals contained within the Schachter-Singer theory is that arousal is not synonymous with emotion.

Lisa Feldman Barrett, Ph.D., illuminates on this, writing:

“The amygdala also showed a consistent increase during studies of anger, disgust, sadness, and happiness, indicating that whatever functions the amygdala was performing in some instances of fear, it was also performing those functions during some instances of those other emotions. Interestingly, amygdala activity likewise increases during events usually considered non-emotional, such as when you feel pain, learn something new, meet new people, or make decisions” (Barrett, 2017).

Schachter and Singer wrote that following James’ pronouncement, a formable number of studies were undertaken in search of physiological differentiators of the emotions.” However, researchers failed to find unique patterns of arousal to match the wide range of emotions. One notable study in 1947, examining the “great variety of moods and emotions” were only abler to identify two patterns of physiological arousal (Schachter & Singer, 1962).

Our biological system arouses from a number of events without us experiencing what we typically label as an emotion. Also, physiological arousal may be similar for a number of different emotions. This suggests that physiological arousal is not the differentiator of emotion. The experience of emotion (or a specific emotion) requires the second factor—a cognitive element.

Cognitive Interpretation

The two-factor theory suggests that for an emotion to exist we must have a cognitive interpretation. Our cognition labels the arousal and creates what we define as an emotion. From the label, we feel happy, sad or angry. We apply various contextual trigger explain the arousal, such as a stressful event or a thrilling experience. The cognitive component involves our subjective perception and assessment of the situation. We lean on experiences, social learning, and variety of elements from the past and present to create an explanation for our arousal.

Barrett wrote:

“Your familiar emotion concepts are built-in only because you grew up in a particular social context where those emotion concepts are meaningful and useful, and your brain applies them outside your awareness to construct your experiences. Heart rate changes are inevitable; their emotional meaning is not” (Barrett, 2017).

History of Schachter-Singer Two Factor Theory

Schachter and Singer’s constructed their theory in line with the changing scientific experiments of the time. Before Schachter-Singer’s 1962 paper several others researchers also experimented with manipulating physiological arousal to better understand emotion.

Initially, Schachter’s research was directed at the impact of social influence on emotion. He was interested in research conducted on self-appraisal conducted by Leon Festinger. He applied Festinger’s research to emotions, leading to a publishing a paper titled The Psychology of Affiliation in 1959 (Dror, 2017). However, in the summary of his 1959 paper, he emphasized the impact of cognitions role in the creation of emotion.

Following Schachter’s 1959 paper, he conducted three experiments in the early 1960’s together with three younger researchers. He intended to publish the three papers together (Schachter & Singer, 1962). The scientific community primarily remembers Schachter and Singer’s paper, Cognitive, Social, and Physiological Determinants of Emotional State, referring to the paper as the foundational study establishing the two-factor theory of emotion or the Schachter-Singer theory of emotion.

In the Schachter-Singer paper they theorized that an emotional state “may be considered a function of a state of physiological arousal and of a cognition appropriate to this state of arousal.” Accordingly, cognition arises from “the immediate situation as interpreted by past experience provide the framework within which one understands and labels his feelings.” What this means, they explain, is that cognitions “determines whether the state of physiological arousal will be labeled as ‘anger,’ ‘joy,’ or whatever” (Schachter & Singer, 1962).

Evaluative Needs

An important aspect of Schachter and Singer’s theory is that arousal prompts a need for explanation. We feel discomfort and need to understand why. They explain that arousal drives cognitive functions “to understand and label…bodily feelings” (Schachter & Singer, 1962).

Typically, surrounding an intense arousal of physiological processes, there is clear environmental elements to draw upon as causes for our emotional discomfort. A person yelling at us. A social encounter. A lover’s kiss. We experience arousal, take note of our surroundings, and arrive at an appropriate emotion—anger, sadness, joy, etc. However, what happens when the environment does not provide clear answers, or the stimuli is rather ambiguous.

Joseph LeDoux wrote:

“This condition of being emotional aroused and not knowing why is all too common for most of us, and was, in fact, the key condition for which the Schachter-Singer theory of emotion tried to account” (LeDoux, 2015).

Roy Baumeister, Todd Heatherton and Dianne Tice explain:

“When no obvious explanation is available for a current mood, people are motivated to seek out possible explanations. When situational explanations are lacking, ambiguous mood states lead people to look inward in order to try to understand the source of the mood” (Baumeister et al., 1994).

The Schachter Singer Experiment

Schachter and Singer’s basic hypothesis was that emotional states are a function of the interaction of cognitive factors occurring during states of physiological arousal. They built their experiment on three propositions:

• Given a state of physiological arousal for which a person has no immediate explanation, they will “label” this state and describe their feelings in terms available to them.
• Given a state of physiological arousal for which an individual has a completely appropriate explanation, no evaluative needs will arise and the individual is unlikely to label their feelings in terms of alternative cognitions available.
• Given the same cognitive circumstances, the individual will react emotionally or describe his feelings as emotions only to the extent that he experiences a state of physiological arousal (Schachter & Singer, 1962).

The Procedure

To test the three propositions, Schachter and Singer designed and experiment that would manipulate arousal and available cognitions. To manipulate arousal, test subjects received an injection of epinephrine (adrenalin) while the control group received and injection of a placebo. An injection of adrenalin creates a near mirror physiological state as arousal of the sympathetic nervous system (systolic blood pressure increases, heart rate increases, cutaneous blood flow decreases, etc.).

Some of the subjects were given a preparatory explanation of these feeling affects, other were given misinformation (numb feet, itching sensations, and a slight headache), and other given no information about possible affects. Schachter and Singer labeled the groups epinephrine informed, epinephrine ignorant, and epinephrine misinformed. Basically some of the subjects knew the injections caused the arousal and some did not.

To induce cognition, a confederate joined the test subjects in a waiting room after the injection and created either a playful environment to induce euphoria cognitions or a displeasing environment to induce angry cognitions.

The Findings

Schachter and Singer found that those without an informed explanation for their physiological arousal were more likely to respond emotionally to the confederate. Basically, they expressed euphoria or anger along with the confederate. Those that had a logical explanation for their emotion (a physical reaction to epinephrine) were less likely to react emotionally to the confederate.

Lessons Drawn from Schachter and Singer’s Experiment

The two-factor theory of emotion provided fodder for decades of research. Some supporting and other doubting Schachter and Singer’s findings. Over the past sixty years since these early findings, cognitive science has expanded exponentially. Yet, many of Schachter and Singer’s early explanations continue to hold true.

Depression and Two Factor Theory of Emotions

Many researchers on depression explain depression in Schachter’s terms of an evaluative need. T. Franklin Murphy describe this as a problem solving approach. He wrote:

“Problem solving is our main reactionary response to disquieting experience. We feel discomfort, find the cause, and pluck out the thorn. In depression, however, the discomfort is not caused by outside interference. There is no external elements to repair or remove. The depression is a reaction to internal mechanisms” (Murphy, 2023).

Mark Williams, John Teasdale, Jon Kabat-Zinn, and Zindel Segal explain:

“Sorting things out will always seem like the most compelling thing to do–figuring out what it is that is not good enough about us, sorting out what we need to do to minimize the havoc that our unhappiness wreaks havoc in our lives if it persists…it simply fuels further unhappiness and keeps us fixated on the very thoughts and memories that are making us unhappy” (Williams et al., 2012).

Attribution Errors

Attribution errors are a crucial aspect of the two-factor theory of emotion, revealing how our cognitive processes can lead to misguided interpretations of our emotional experiences. When we undergo physiological arousal but lack a clear explanation for it, we tend to draw from past experiences to label that arousal.

This means that instead of accurately identifying the source or nature of our feelings, we may misattribute them to unrelated events or stimuli from our past. For instance, if someone feels their heart racing in a stressful situation but cannot pinpoint why they feel anxious, they might mistakenly attribute their heightened state to an unrelated memory or event—such as recalling an argument with a friend—rather than recognizing the immediate context that triggered their response.

These misattributions can have significant implications for how individuals respond emotionally and behaviorally. By inaccurately labeling their emotions based on past experiences rather than current circumstances, people risk adopting maladaptive responses that do not address the actual cause of their discomfort. For example, someone who frequently misattributes anxiety from present situations may develop generalized anxiety disorder due to consistent overreactions stemming from these errors in judgment.

Recognizing the tendency towards attribution errors is essential for fostering emotional awareness and improving mental health outcomes; by understanding this dynamic within ourselves, we can work towards more accurate self-assessments and healthier coping mechanisms when faced with emotional distress.

Associated Concepts

• Cognitive Appraisal: This refers to the individual’s assessment of an event as significant for their well-being, which is central to the Two-Factor Theory as it involves the interpretation of physiological arousal to experience emotion.
• James-Lange Theory of Emotion: This earlier theory posits that emotions occur as a result of physiological reactions to events. The Two-Factor Theory builds on this by adding the cognitive label to the physiological response.
• Cannon-Bard Theory of Emotion: This theory suggests that we feel emotions and experience physiological reactions simultaneously, not sequentially as in the Two-Factor Theory.
• Cognitive- Arousal Theory: It focuses on the arousal aspect of emotion, which is one of the two factors in the Two-Factor Theory. Arousal Theory examines how arousal is necessary for emotion but does not dictate the direction or type of emotion.
• Lazarus’s Cognitive-Appraisal Theory: This theory describes how emotions originate from our interpretations of external stimuli, through primary and secondary appraisals. Primary appraisal assesses an event’s personal significance, while secondary appraisal evaluates coping abilities.
• Frustration-Aggression Hypothesis: This hypothesis proposed by John Dollard in 1939 suggests that frustration often leads to aggressive behavior. This theory has evolved to recognize a variety of responses to frustration and the influence of individual differences and environmental factors.

A Few Words by Psychology Fanatic

The two-factor theory of emotion suggests that emotions are not simply instinctual reactions to stimuli but created through a cognitive process. It highlights the importance of both physiological responses and cognitive interpretation in shaping our emotional experiences. By recognizing the role of cognition, we can access a new avenue to soothe arousal.

Emotions are an intricate interplay between our minds and bodies. Accordingly, complex systems contribute to this fundamental part of our experience of living. With effort, and sometimes professional guidance, we can better navigate the complex world of emotions.

In conclusion, the two-factor theory of emotion offers valuable insights into how our physiological arousal and cognitive appraisal contribute to our emotional experiences. It reminds us that emotions are multifaceted phenomena, involving both physical reactions and interpretations to make sense of those reactions. Consequently, by understanding these factors, we can reevaluate the emotions disrupting our lives. Accordingly, we gain a deeper appreciation for the complexity of human emotions.

Last Update: February 9, 2026

References:

Barrett, Lisa Feldman (2017) How Emotions Are Made: The Secret Life of the Brain. Mariner Books; Illustrated edition. ISBN-10: 1328915433; APA Record: 2017-26294-000
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Baumeister, R. F., Heatherton, T. F., & Tice, D. M. (1994). Losing control: How and why people fail at self-regulation (1st ed.). Academic Press. ISBN-10: 0120831406; APA Record: 1994-98882-000
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Dror, Otniel (2017). Deconstructing the “Two Factors”: The Historical Origins of the Schachter–Singer Theory of Emotions. Emotion Review, 9(1), 7-16. DOI: 10.1177/1754073916639663
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LeDoux, Joseph (2015). The Emotional Brain: The Mysterious Underpinnings of Emotional Life. Simon & Schuster. ISBN-10: 0684836599; APA Record: 1996-98824-000
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Murphy, T. Franklin (2023). Mindfulness Based Cognitive Therapy. Psychology Fanatic. Published: 8-18-2023; Accessed: 8-28-2023. Website: https://psychologyfanatic.com/mindfulness-based-cognitive-therapy/
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Schachter, S., & Singer, J. (1962). Cognitive, social, and physiological determinants of emotional state. Psychological Review, 69(5), 379-399. DOI: 10.1037/h0046234
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Williams, Mark G.; Kabat-Zinn, Jon; Teasdale, John; Segal, Zindel, and Teasdale, John D. (2012). The Mindful Way through Depression: Freeing Yourself from Chronic Unhappiness. The Guilford Press; Paperback. ISBN-10: 1593851286; APA Record: 2007-10791-000
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