Medicine & USMLE

Schachter-Singer (Two Factor) Theory of Emotion

  1. Schachter-Singer (Two Factor) Theory of Emotion
  2. James-Lange Theory of Emotion
  3. Cannon-Bard Theory of Emotion


The Schachter-Singer Theory, also known as the Two-Factor theory of emotion, states that 2 factors are needed to experience emotion. First, environmental stimuli elicits a physiological response. Second, we cognitively appraise this physiological activity, and try to give it the correct label. Emotions are produced as a result of this cognitive labeling.

Key Points

  • Schachter-Singer Theory of Emotion
    • Also known as the two-factor theory
    • Environmental event (stimulus) → physiologic response → cognitive appraisal → emotion
      • Adds onto James-Lange Theory of Emotion by stating that two factors are needed:
        • physiologic response, and
        • cognitive label
      • Emotion is the cognitive labelling/interpretation of a physiological response.


Say you hear scratching at the door and you open the door to see a large growling pitbull. In response, your heart starts racing, and you start sweating.

However, a racing heart and sweating can happen in other contexts, right? Think about the joy you get at a concert, or maybe after winning a soccer game. In both of these contexts, you can have the same physiologic response of a racing heart and sweating, but they correspond to completely different emotions.  So how do you know that in front of this growling dog, your racing heart is actually fear and not something like exhilaration or excitement? Well, the answer is cognitive labelling.  Your brain searched your environment for cues that help it decide why the physiological arousal is happening. When it sees the pitbull, your brain labels the situation as something that should cause fear. In short, this cognitive labelling is responsible for experiencing the correct emotion.

Find this mnemonic and more Theories of Emotion among Pixorize's visual mnemonics for the MCAT exam.