Two-factor theory of emotions The experiment of Schachter and Singer (1962): Gregorio Marañon (1924) found that participants did not experience a genuine emotion after injection of epinephrine. There was one exception: If participants were asked to imagine how their parents die or how their children get ill, participants felt a genuine emotion, but only if this instruction was given after the injection of epinephrine. If it was given before, no effect could be observed. Contributor © POSbase 2003

Two-factor theory of emotions This led several authors to postulate a two-factor theory of emotions, assuming that an emotion is determined by two factors: Unspecific physiological activation. This is a necessary, but not sufficient condition to elicit an emotion. Cognitive interpretation of the situation determines the quality of an emotion. Stanley Schachter and Jerome Singer tested the two-factor theory in a now classical study. The logic behind their experiment was the following: © POSbase 2003

Experiment of Schachter and Singer If there exists physiological arousal for which there is no explanation:  Quality of emotion depends on cognitive interpretation. The same state of physiological arousal can be experienced as either joy or anger. If physiological arousal can be explained:  No emotion. Identical cognitive interpretations elicit an emotion only if there is physiological arousal. © POSbase 2003

Experiment of Schachter and Singer Hypotheses: Epinephrine P Placebo A Informed A Not informed A Misinformed Euphoria Anger Euphoria Neutral Anger Neutral © POSbase 2003

Experiment of Schachter and Singer Results: Self report Epinephrine P Placebo A Informed A Not informed A Misinformed Euphoria 1.61 1.78 1.90 0.98 In both conditions: The higher number denotes more positive emotions Anger 1.39 1.91 1.63 © POSbase 2003

Experiment of Schachter and Singer Results: Behavior Epinephrine P Placebo A Informed A Not informed A Misinformed Euphoria 16.00 18.28 22.56 12.72 Euphoria The higher, the more euphoria Anger: The higher, the more anger Anger 2.28 -0.18 0.79 © POSbase 2003

Experiment of Schachter and Singer Conclusion: The hypotheses of the two-factor theory of emotions were only partly confirmed, and some other studies did not provide support for or even contracdicted the two-factor theory of emotion (Lazarus et al., 1965; Maslach, 1979; Marshall & Zimbardo, 1979). However, this study stimulated many other experiments on the role of arousal and cognitive appraisal of the situation (e.g., Dutton & Aron, 1974; Zillmann et al., 1972) Results: Behavior Epinephrine P Placebo A Informed A Not informed A Misinformed Euphoria 16.00 12.72 18.28 22.56 Euphoria The higher, the more euphoria Anger: The higher, the more anger Anger 0.79 -0.18 2.28 © POSbase 2003