Two-factor theory of emotion

Stanley Schachter and Jerome E. Singer (1962) performed a study that tested how people use clues in their environment to explain physiological changes. Their hypotheses were:

• If a person experiences a state of arousal for which they have no immediate explanation, they will label this state and describe their feelings in terms of the cognitions available to them at the time.
• If a person experiences a state of arousal for which they have an appropriate explanation (e.g. 'I feel this way because I have just received an injection of adrenaline'), then they will be unlikely to label their feelings in terms of the alternative cognitions available.
• If a person is put in a situation, which in the past could have made them feel an emotion, they will react emotionally or experience emotions only if they are in a state of physiological arousal.

Participants were told they were being injected with a new drug called "Suproxin" to test their eyesight. The participants were actually injected with epinephrine (which causes respiration, an increase in blood pressure and heart rate) or a placebo. There were four conditions that participants were randomly placed in: epinephrine informed, epinephrine ignorant, epinephrine misinformed, and a control group. The epinephrine informed group was told they may feel side effects including that their hands would start to shake, their heart will start to pound, and their face may get warm and flushed. In the epinephrine ignorant group, the experimenters did not explain to the subjects what symptoms they might feel. The epinephrine misinformed group was told that they would probably feel their feet go numb, and have an itching sensation over parts of their body, and a slight headache. The control group was injected with a placebo and was given no side effects to expect. This group was used as a control because they were not experiencing a physiological change and have no emotion of label. After the injection, a confederate interacted with the students, who was either acting euphoric or angry.[1] The experimenters watched through a one way mirror and rated the participants' state on a three category scale. The participants were then given a questionnaire and their heart rate was checked.

The researchers found that the impact of the confederate was different for the participants in the different conditions. From high to low euphoria their ranking was as follows: epinephrine misinformed, epinephrine ignorant, placebo, epinephrine informed. In the anger condition the ranking was: epinephrine ignorant, placebo, epinephrine informed. Both results show that those participants who had no explanation of why their body felt as it did, were more susceptible to the confederate. These findings are considered to support the researchers' hypotheses.[1]

Criticism of the theory has come from attempted replications of the Schachter and Singer (1962) study. Marshall and Zimbardo (1979, and Marshall 1976) tried to replicate the Schachter and Singer’s euphoria conditions. Just as Schachter and Singer did, the subjects were injected with epinephrine or a placebo, except the administrator told the subjects that they will be experiencing non-arousal symptoms. Then the subjects were put into four different conditions: subjects injected epinephrine and were exposed to a neutral confederate, another in which they received the placebo and were told to expect arousal symptoms, and two conditions in which the dosage of epinephrine was determined by body weight rather than being fixed.[5] The results found that euphoria confederate had little impact on the subjects. Also, that the euphoric confederate didn’t produce anymore euphoria than the neutral confederate did. Concluding that the subjects who were injected with epinephrine were not more susceptible to emotional manipulations than the non-aroused placebo subjects.

Maslach (1979) designed a study to try to replicate and extend on the Schachter and Singer study. Instead of being injected with epinephrine, the administrators used hypnotic suggestions for the source of arousal. Either the subjects were hypnotized or were used as a control (same as the placebo effect in the Schachter and Singer study). Subjects that were hypnotized were given a suggestion to become aroused at the presentation of a cue and were instructed not to remember the source of this arousal.[6] Right after the subjects had been hypnotized, a confederate began acting either in a euphoric or angry condition. Later on in the study the subjects were exposed to two more euphoric confederates. One confederate was to keep aware the source of the arousal, while the other confederates told the subjects to expect different arousal symptoms. The results found that all the subjects both on self-reports and on observation found that unexplained arousal causes negative conditions. Subjects still showed angry emotions regardless of the euphoric confederate. Maslach concluded that when there is a lack of explanation for an arousal it will cause a negative emotion, which will evoke either anger or fear. However, Maslach did mention a limitation that there might have been more negative emotion self-reported because there are more terms referring to negative emotions than to positive ones.[7]

There are also criticisms of the two-factor theory that come from a theoretical standpoint. One of these criticisms is that the Schachter-Singer Theory centers primarily on the autonomic nervous system and provides no account of the emotional process within the central nervous system aside from signaling the role of cognitive factors. This is important considering the heavy implication of certain brain centers in mitigating emotional experience (e.g., fear and the amygdala).[8]

It can also be noted that Gregorio Marañon also had early studies in the development of cognitive theories of emotion and should be recognized for making contributions to this concept.[9]

• Cannon–Bard theory
• James–Lange theory
• Misattribution of arousal

• Cotton, J. L. (1981). "A review of research on Schachter's theory of emotion and the misattribution of Arousal". European Journal of Social Psychology. 11 (4): 365–397. doi:10.1002/ejsp.2420110403.
• Dutton, D. G.; Aron, A. P. (1974). "Some evidence for heightened sexual attraction under conditions of high anxiety". Journal of Personality and Social Psychology. 30 (4): 510–517. CiteSeerX 10.1.1.335.100. doi:10.1037/h0037031. PMID 4455773.
• Erdmann, G.; Janke, W. (1978). "Interaction between physiological and cognitive determinants of emotions: Experimental studies on Schachter's theory of emotions". Biological Psychology. 6 (1): 61–74. doi:10.1016/0301-0511(78)90007-8. PMID 623859. S2CID 597601.
• Izard, C. E. The face of emotion. New York: Appleton-Century-Crofts, 1971.
• LeDoux, J. E. (1995). "Emotion: Clues from the brain". Annual Review of Psychology. 46: 209–235. doi:10.1146/annurev.ps.46.020195.001233. PMID 7872730.
• Marshall, G. D. (1976). The affective consequences of "inadequately explained" physiological arousal. Unpublished doctoral dissertation, Stanford University.
• Marshall, G. D.; Zimbardo, P.G. (1979). "Affective consequences of inadequately explained physiological arousal". Journal of Personality and Social Psychology. 37 (6): 970–988. doi:10.1037/0022-3514.37.6.970.
• Maslach, C (1979). "Negative emotional biasing of unexplained arousal". Journal of Personality and Social Psychology. 37 (6): 953–969. doi:10.1037/0022-3514.37.6.953.
• Pruett, C (2011). "Two-factor theory of emotion displayed by video games". Game Developer. 18 (2): 33.
• Schachter, S.; Singer, J. (1962). "Cognitive, Social, and Physiological Determinants of Emotional State". Psychological Review. 69 (5): 379–399. doi:10.1037/h0046234. PMID 14497895.
• Schachter, S.; Wheeler, L. (1962). "Epinephrine, chlorpromazine, and amusement". Journal of Abnormal and Social Psychology. 65 (2): 121–128. doi:10.1037/h0040391. PMID 14497896.

• A Powerpoint presentation describing Schachter & Singer's experiment
• A Powerpoint presentation describing Dutton & Aron's experiment