Determinants of Emotional State


The physiological side to emotion has been discussed for centuries, even by Aristotle. A few decades ago, Stanley Schachter and Jerome Singer, two American psychologists, put their heads together one day and came up with the “two-factor theory of emotion”. This theory states that emotion results from a combination of two things: (a.) state of arousal, and (b.) an interpretative cognition. Also, it says that when people feel an emotion, they look for a reason as to why they feel that way. Schachter and Singer decided to test this theory with an experiment.

Stanley Schachter

Stanley Schachter

Jerome Singer

Jerome Singer

Three hypotheses were given:

      1. If a person experiences a state of arousal for which they have no immediate explanation, they will interpret that emotion with the cognitions available to them at the time.
        Example: You are walking down a dark, dirty alleyway at 2 AM (idiot!). Your heart is beating fast, you are trembling and your breathing is deep. You realise this is occurring because you are walking down this scary alleyway, and you conclude that you are feeling an emotion: fear.
      2. If a person experiences a state of arousal for which they have an appropriate explanation, then they will be unlikely to describe that emotion using alternative available cognitions.
        Example: You are walking home alone. Your breathing is deep, your heart is beating a little faster and you feel drowsy. You have just taken an injection at the hospital and you think: I am feeling this way because of the injection I took.
      3. If a person is put into a situation which, in the past, made them feel a certain emotion, then they will experience emotions if they are in a state of physiological arousal.

The sample was made up of 184 male college students at Minnesota University who were taking classes in Introductory Psychology. 90% of these students received two extra points on their final exam for every hour they spent as a participant. Since adrenaline was used in this study, the participants’ health records were checked to make sure that there would be no adverse side effects.

When the participant arrived, the experimenter took him to a private room. He was told that the aim of the experiment was to “look at the effects of vitamin injections on visual skills” and was asked if he had any problem with taking an injection of Suproxin (this was actually a made-up name). 184 (out of an original 195) subjects agreed and went ahead with the experiment.

The participant was injected by a doctor and given one of two things: (a.) adrenaline, also called epinephrine, or (b.) a placebo, which was just a salt and water solution.

The effects of adrenaline are: increased blood pressure, heart rate, blood sugar level, respiration rate and blow flow to the muscles and brain, but a decrease in blood flow to the skin. These effects usually result in palpitations, tremors, flushing and fast breathing. The effects begin after three minutes and last anywhere between ten minutes to one hour.

The saline solution of salt and water has absolutely no side effects.

There were four experimental conditions. The subjects were put into one of the following:

  1. Adrenaline ignorant: Subjects were given a shot of adrenaline and not told about any side effects.
  2. Adrenaline informed: Subjects were given a shot of adrenaline and told about all the side effects.
  3. Adrenaline misinformed: Subjects were given a shot of adrenaline and told about side effects which were actually false (like numb feet and headaches).
  4. Control group: They were given the placebo and not told about any side effects.

Remember, the subjects thought they were taking in Suproxin – a fake vitamin. After this, the second part of the experiment began.

The doctor left the room and the experimenter returned with a stooge (an actor). The stooge was introduced as another participant who had taken the same Suproxin injection. They were told to wait for 20 minutes so that the vitamin could be absorbed into the bloodstream, after which they would be given tests of vision. This part continued in two different ways, meaning there were two different conditions: the euphoria condition and the anger condition.

Euphoria condition
In this condition, the waiting room was systematically put into a state of mild mess. As the experimenter was leaving, he apologetically added that if the participant wanted any rough paper, rubber bands or pencils then they should help themselves. As soon as the experimenter left, the stooge would introduce himself again, make a few ice-breaker comments and then begin a standardised routine. He played with items and encouraged the participant to join him.

Anger condition
In this condition, the participants were told to complete a questionnaire. Before looking at the questionnaires, the stooge said to the participant that he thought it was unfair to receive injections without being told when they were first called. They became the questionnaire normally… until it got personal! Questions asking about private topics (e.g. How many times each week do you have sexual intercourse?) came up and the stooge became making a series of standardised comments which started off innocently but grew increasingly annoyed, until he finally ended in a rage.

The routine for both conditions (i.e. euphoria and anger) was standardised and the stooge never knew which condition (i.e. adrenaline informed, adrenaline misinformed, adrenaline ignorant or control group) the participant was in.

The adrenaline misinformed condition was not run in the anger sequence. This is because it was originally created as a control condition so if it was included in the euphoria sequence, that would be enough to evaluate any effects of being in the adrenaline misinformed condition. A second sequence was not needed.

To summarise the above, look below:

EUPHORIA  –  Adrenaline ignorant/Adrenaline informed/Adrenaline misinformed/Control
ANGER          – 
Adrenaline ignorant/Adrenaline informed/Control

The researchers made observations of the participants’ emotional response through a one-way mirror and took self-report measures from the subjects. A self-report questionnaire contained a number of mock questions but there were a few crucial ones that measured mood and emotion, for example: How irritated, angry or annoyed would you say you feel at present?

When the participants completed the questionnaire, the experimenter told them the experiment was over and explained the deception in detail. They also answered any questions and swore the subjects to secrecy. Finally, the participants answered a last questionnaire about the experimental experience with adrenaline and if they had any suspicions about being deceived. It turns out that 11 of the participants were so suspicious that their data was automatically discarded!

The results showed that participants who received adrenaline injections showed significantly more sympathetic arousal, compared to the placebo group. This was measured by pulse rate and self-ratings on palpitation, tremor, numbness, itching and headaches. Five participants were excluded because they did not show any relevant symptoms after receiving adrenaline.

In the euphoria condition, adrenaline-misinformed participants were the most happiest, then it was the adrenaline-ignorant group. This shows that these participants were more susceptible to the stooge because they had no explanation of why their bodies were experiencing certain arousals. The informed group felt the least happy. This is because they knew the reason behind their emotional arousal.

In the anger condition, the adrenaline-ignorant group felt the angriest, then the placebo group. The least angry group was the adrenaline-informed group. Again, this is because they had an explanation to their emotions whereas the other groups had none.

Looking at the above, the original hypotheses were supported by the experimental results.

two factor theory

The behaviour was measured through a one-way mirror and it supported the results from self-reports.

Type of research method
This was a laboratory experiment with manipulated variables and scientific apparatus.

Independent variable
There were two independent variables: the information given to the subjects about the injection they were given (i.e. were they ignorant, informed or misinformed?) and the situation they had to experience (i.e. anger or euphoria).

Dependent variable
The emotional arousals of the participant.


  1. High level of control: There was an extremely high level of control in this experiment. This means that there is less chance of any extraneous variables affecting the results.
  2. Replicable: The procedure was completely standardised in terms of allocating random participants, giving each group member the same information, following a standard sequence in both conditions and even keeping the stooge unaware. This means that, overall, this experiment can be easily replicated and the accuracy of the results can be checked, meaning that it is possible to check the reliability of the results.
  3. Control over demand characteristics: The use of a one-way mirror to observe the participants’ reactions meant that there was much less chance of any demand characteristics occurring. If the participants knew someone was watching them, they may have behaved differently.


  1. Lack of ecological validity: The experiment was conducted in an artificial setting but the main reason for its lack of ecological validity was the way the researchers induced emotions into the participants. Usually, humans are aware of an event before they experience an emotional arousal. Here, the participants were artificially provoked into a state of arousal.
  2. Not generalisable: The sample was made up of male students from the same university. This means the results cannot be generalised to females or people from other areas. The sample is unrepresentative; we can argue that females may experience emotions differently to males.

Ethical issues

  1. Informed consent: The participants did give consent to receive an injection, although they did not know that it was adrenaline.
  2. Deception: Participants were deceived about the adrenaline (they thought it was Suproxin), they were deceived about the nature of the experiment, they were deceived by the stooge… you get the picture.
  3. Confidentiality: Yes, the confidentiality of participants was seemingly respected. No one was publicly named.
  4. Emotional or physical harm: Since the medical records of participants were checked beforehand, there was no physical harm. There was also nothing to suggest that participants were emotionally harmed, although they may have felt feelings of awkwardness or embarrassment in the anger condition.
  5. The right to withdraw: Schachter and Singer did not seem to stop any participants from leaving the experiment. In fact, a few participants who did not want to receive an injection left at the beginning.
  6. Debriefing: Participants were thoroughly debriefed after the experiment, given answers to any questions they had and also sworn to secrecy. So, eventually, they were told about what was actually going on.

Reference: Schachter, S. and Singer, J. E. (1962). Cognitive, Social and Physiological Determinants of Emotional State. Psychological Review. 69 (5): 379-399.

13 thoughts on “Determinants of Emotional State

  1. Psychology exam in 2 days, any tips ? I’ve studied a lot, but I’m just really nervous since its AS Levels

    • Hi Jonathan,

      Aw, it’s understandable that you’re feeling the nerves but, honestly speaking, if you have studied well then there is no reason to worry. By now, you should have completed a fair amount of past papers and also read all the original research papers – have you done that? Also, it would help to just go through all the basic information, such as core definitions! Make a list (or find one) and go through them. You can also read through the Sample Answers booklet if you haven’t already done so.

      Other than that, just relax yourself and be positive! There’s only so much you can do in two days so don’t overwork yourself now, especially if you’ve been productive over the past few months.

      Let me know if there’s anything I can do to help you out in the meantime!

      Best of luck,

  2. In one of the past papers (w2014), the effects are marked incorrect because these are the scientific effects of adrenaline and not the one Schachter & Singer told the group about. I can’t find the original research pdf anywhere, so can you help me confirm what other instances the information was different? (Like, what exactly the misinformed group were told?)
    Thank you for your prompt reply on my previous comment as well! (:

    • Asa Ayesha ,
      I think so I remember this one for informed group they were told about increase in heart rate i.e they can feel their “heart will pound “and tremour “shaking of their hands ”
      And for misinformed group was “numbing of feet , slight headache and itching sensation over parts of your body “

      • Thank a bunch, DoubleNN!
        So, if there was a question about the length of these effects (and they don’t specify whether generally or what S&S claimed) would the correct answer be 15-20 mins or 10-60 mins?
        I’m just realising how over-cautious I am…

        • I believe it is suppose to be 15 -20 minutes because they want nothing to do with general information .
          Bdw if you dont mind me asking – about how much do you just score in section A and then separately in B . And are you giving A2 as well now ?
          I actually donot really know much people giving this subject . So I hope you didnt mind !

          • Oh ok, thanks!
            You mean when I attempt past papers and check the scores myself? I’m not sure about Section B but I usually score in late 40s (47, 49) for Section A. What about you? (I hope I didn’t misunderstood your question)
            No, I’m only doing AS rn. Of course, I don’t mind! c:

            • Thanks 🙂
              Oh WOW ma sha Allah ur going pretty good !
              Hahaha – i score ( totally embarassing ) in 30’s range usually !
              Pls give me tips ! That would be really helpful as you can already see , haha .
              Basically , how do u go through the studies ? And how to do you attempt the paper ?

              • Oh, that’s good? I actually had no idea. I’m probably being too lenient on myself though haha.
                I use online flashcards site called ‘quizlet’, it also has an app so I go through my flashcards (made mostly thanks to this site, bless) whenever possible. Since there’s not much time left, you can search for cards made by other users instead of making your own but be vary: not all of them are correct or comprehensive!
                Hope that’ll help! 🙂

  3. Asa ! Hope all is well .
    Maryam could u please help me to evaluate this study interms of individual vs situational explanations . I know this evaluation applies in this study as all my books say it does but they dont say how and i am pretty confused on how to do it by myslef .
    So please help me out here !

    • Walaikumassalaam!

      Firstly, you must know the meaning of those two terms. They both are generally used to explain behaviour.

      Individual explanation – states that behaviour is a result of an individual’s own personality/characteristics.
      Situational explanation – states that behaviour is a result of the situation or environment that they are in/experiencing.

      With regards to this study, we can evaluate it like so: the individual explanation would imply that the behaviour shown due to physiological arousal during the study (i.e. Anger/euphoria) is because the individuals are predisposed to these emotions. For example, the adrenaline-ignorant group felt the angriest and this must be because they are naturally more likely to become angry than the other groups.

      On the other hand, the situational explanation states that physiological arousal and behaviour was due to the situation that the individuals were experiencing. For example, the adrenaline-ignorant group felt angrier simply because they were in that specific condition, not because they are naturally predisposed to anger.

      Does that make sense? Let me know if you need me to elaborate.

      Best wishes,
      Maryam XXX

  4. Stan was my graduate advisor at Columbia University, 1979 to 1984; and we remained close up until his death. He taught me how to think about real world problems in what was often an unorthodox and controversial manner, and I have attempted to carry his lessons forth to my own students. One important thing to point out: Often, we are judged by our c.v.’s, how many publications, how many citations, and certainly Stan, who made his mark in several areas, had a c.v. that most of us would kill for. But there is another criterion by which to judge, and that is in the productivity of one’s students after they have gone off from graduate school, and Stanley sent out an army of what were to become significant figures in the study of social psychology. I would guess that he was unrivaled in this. And the result was that he had a profound impact on the field.
    He had a very strong personality. Here is a story from my past. Stan and his wife Sophia summered in a beach house in Amagansett, near the Hamptons. During the summer, his 4th year grad students, who were preparing their dissertations, would trudge out there – several hours on the train – to discuss their theses with Stanley. I went out there, showed him my Introduction (I was very proud that it was printed using one of the new-fangled dot matrix printers). He read what I had written while I went fishing with his son. When I returned, expecting praise for my work, I met instead an irate Stan Schachter, who hated my intro. We discussed it, I understood what I was to do, and planned to go back to New York City to my brand new (original) Macintosh computer to revise, but alas, it was not to be. Stan sent me upstairs to the attic – i swear – where there was an old, portable, manual Remington typewriter (with sticky keys) and a stack of foolscap, coarse yellow paper. Essentially, he locked me in the attic where I re-wrote my intro – not just a few paragraphs but the whole thing! After around five hours I went downstairs to show him, he read it, and it was pretty much what we had discussed. At that time, Stanley was in the process of playing an important role in the new field of Behavioral Economics (after making his mark in an astonishing range of topics); as it was new, there was little literature, and my introduction was only a few pages long (compared to the typical telephone book produced by most Ph.d. candidates).
    Stan is one of the few deceased people in my life whom, when I come across something interesting, I think “I’ll have to discuss this with Stanley”… until I remember that he’s gone.

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