Have you ever felt frightened, or happy, without really knowing why? Why are highly pressurised environments more likely to lead to sudden outbursts of emotion or highly passionate relationships? Our emotional state may have more effect on our behaviour than we realise. But where does this emotion come from? What causes it? Schachter and Singer helped us to find out.

What are emotions?

Emotions didn’t get much of a look in for much of the history of human thought. Philosophers such as Descartes and Kant ignored emotions and focused on humans as rational beings, who made decisions using logic. William James was one of the first psychologists to study emotion scientifically. You can read about the early James-Lange and Cannon-Bard theories of emotion here. The debate between two early theories of emotion formed the background to Schachter and Singer’s experiment.

What Is the Two-Factor Theory?

Like the James-Lange theory of emotion, Schachter and Singer felt that physical arousal played a primary in emotions. However, they suggested that this arousal was the same for a wide variety of emotions, so physical arousal alone could not be responsible for emotional responses.

The two-factor theory of emotion focuses on the interaction between physical arousal and how we cognitively label that arousal. In other words, simply feeling arousal is not enough; we also must identify the arousal in order to feel the emotion.

So, imagine you are alone in a dark parking lot walking toward your car. A strange man suddenly emerges from a nearby row of trees and rapidly approaches. The sequence that follows, according to the two-factor theory, would be much like this:

1. I see a strange man walking toward me.
2. My heart is racing and I am trembling.
3. My rapid heart rate and trembling are caused by fear.
4. I am frightened!

The process begins with the stimulus (the strange man), which is followed by the physical arousal (rapid heartbeat and trembling).

Added to this is the cognitive label (associating the physical reactions to fear), which is immediately followed by the conscious experience of the emotion (fear).


Cognitive, social and physiological determinants of emotional state – Schachter, S. and Singer, J.E. (1962)

Alternative Study

Schachter and Singer conducted a lab experiment to investigate their two-factor theory of emotion. An alternative method of conducting an investigation with a similar aim would be to perform a field experiment.

  1. Describe the field experiment as a research method in Psychology. (5)
  2. Write a description of the study, including the who, what, where and how. (10)
  3. What would the advantages and disadvantages of such an experiment be, compared to the original? Evaluate this new study in methological and ethical terms. (10)

Big Issue/s: Qualitative vs Quantitative Data

  • Quantitative data is data involving numbers. Anything involving frequencies, numbers and measurement will produce quantitative data. Methods that produce quantitative data include experiments, likert scales and psychometric tests.
  • Qualitative data is data involving descriptions. Methods that produce qualitative data include case studies and interviews.
  • Some methods, such as observational studies and questionnaires, could produce either or both types of data, depending on the design and the DV being investigated.
  • Many modern studies (and many of the studies here) will collect both types of data, using qualitative observations to back up quantitative statistics.

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MindMap of the Study


Test Yourself: Flashcards (pre-2018)

Below are Paper 1 questions that have been asked on Schachter & Singer. Learn the answers, then test yourself.
[qdeck] [q]From the study by Schachter and Singer (emotion):

(a) Identify the two factors from the two-factor theory of emotion. [2]

(b) How was each factor manipulated in the study? [2] [a](a) Arousal/physiological component and cognitive/psychological componen

(b)Arousal manipulated by injection/with adrenalin or placebo

Cognition manipulated by angry or euphoric situation

Cognition manipulated by information or misinformation

[q]From the study by Schachter and Singer (emotion):

(a) Identify the two methods used to record the responses of participants. [2]

(b) Outline an advantage of one of these methods. [2] [a](a)

  • observation
  • self report
  • pulse rate.

(b) Observation:

  • standardised (agreed categories)
  • through a one-way mirror (reduced demand characteristics)
  • valid as participant believed the context was ‘semi-private’ (known only to one other person – the one in the room with them).

    self report:
  • assessed mood rather than behaviour (i.e. internal states that cannot be directly observed)
  • used some open questions (so able to collect detailed data).
[q]From the study by Schachter and Singer on emotion:

(a) Outline one way in which the self report method was used. [2]

(b) Outline one way in which the observation method was used. [2] [a](a) Self report on two main scales: mood and physical condition.

(b) Observation through a one-way mirror. 4 categories: 1. joins in; 2. initiates new activity; 3. ignores stooge; 4. watches stooge. 88% agreement.

[q]From the study by Schachter and Singer (emotion):

(a) All the participants in this study were cleared by the student health service. Give two features of the sample apart from being cleared. [2]

(b) Describe why the experimenters had to clear every participant with the student health service. [2] [a](a)

  • male
  • (college) students
  • taking introductory psychology
  • at University of Minnesota
  • (90%) received (2) extra points on final exam (for every hour they served as an experimental subject).

(b) To ensure no harmful effects would result (from the injection of adrenaline / epinephrine / saline).

[q]From the study by Schachter and Singer (emotion), identify four of the categories used by observers to code the behaviour of the participants in the anger condition. [4] [a]1 agrees / says he is cross too (e.g. copies the stooge)

2 disagrees / e.g. ‘take it easy, they probably have a good reason for wanting the information’

3 neutral / noncommittal or irrelevant remark

4 initiates agreement or disagreement / comment without instigation by stooge

5 watches/no comment, but looks at the stooge

6 ignores/no comment, but doesn’t look at the stooge

[q]From the study by Schachter and Singer (emotion), identify four objects used by the stooge in the euphoria condition. [4] [a]rubber band/slingshot, paper (accept paper plane and crumpled paper used as a ball as two), pencils, waste bin, (manilla) folders, (hula) hoop

[q]From the study by Schachter and Singer on emotion:

(a) Outline one method that was used to record the responses of the participants. [2]

(b) What is the advantage of using this method in this study? [2] [a](a) EITHER: standardised observation through a one-way mirror
OR: self report on a number of scales.

(b) Observation allows observers to record actual behaviours of participants.

Self reports allow participants to say what they think about what goes on.

[q]From the study by Schachter and Singer (emotion):

(a) What reasons did the experimenter give the participants for the 20-minute delay in the anger condition after they had been given the injection? [2]

(b) What was the real reason for this delay? [2] [a](a)“the Suproxin to get from the injection site into the bloodstream” he continued “We would like use to use these 20 minutes to answer these questionnaires…”

To allow time for the stooge to demonstrate angry behaviour (to provide a contrast to the effect of the euphoric stooge) to see whether the cognitive labels provided by the stooge’s behaviour would affect the participant’s interpretation of their physical arousal.

[q]In the study by Schachter and Singer (emotion), the experimenter deceived the participants.

(a) State two ways in which the participants were deceived. [2]

(b) Suggest why it was necessary to deceive the participants in this study. [2] [a](a)

  • saline/placebo not ‘Suproxin’
  • effects of Suproxin (in some groups)
  • test of emotion not vision
  • purpose of questionnaire
  • role of stooge reason for delay


  • to avoid them guessing the aim about emotion/arousal/cognition
  • to avoid them responding differently to the adrenalin/stooge
[q]From the study by Schachter and Singer (emotion):

(a) Describe what the epinephrine informed group (Epi Inf) were told about the effects of Suproxin. [2]

(b) (b) Describe what the epinephrine misinformed group (Epi Mis) were told about the effects of Suproxin. [2] [a](a) “Epinephrine Informed. I should also tell you that some of our subjects have experienced side effects from the Suproxin. These side effects are transitory, that is, they will only last for about 15 or 20 minutes. What will probably happen is that your hand will start to shake, your heart will start to pound, and your face may get warm and flushed. Again these are side effects lasting about 15 or 20 minutes.”

(b) “Epinephrine Misinformed. I should also tell you that some of our subjects have experienced side effects from the Suproxin. These side effects are transitory, that is, they will only last for about 15 or 20 minutes. What will probably happen is that your feet will feel numb, you will have an itching sensation over parts of your body, and you may get a slight headache. Again these are side effects lasting about 15 or 20 minutes.”

[q]The study by Schachter and Singer (emotion) used a physiological measure to assess the effect of epinephrine.

(a) Name this physiological measure and describe how it changed when epinephrine was given to the participants. [2]

(b) Describe how the change in participants given epinephrine differed between the euphoria and anger conditions. [2] [a](a)

  • pulse rate
  • in beats per minute/bpm
  • increased rate
  • in all conditions


The anger groups’ pulses were faster.
EpiInf: euphoria = 88.6, anger = 92.4 bpm
EpiIgn: euphoria = 85.6, anger = 96.8 bpm

Epinephrine produced a greater increase in pulse in anger, smaller increase in euphoria condition (2 marks) In euphoria informed faster than ign/mis but in anger informed slower than ign (2 marks)

[q]Use Schachter and Singer (emotion) to discuss the physiological approach. [10] [a]
  • Physiological investigation, e.g. hormones, endocrine system, adrenaline, its effects (palpitations, tremor, face flushing etc.), adrenal glands (other examples may be relevant), role of adrenaline in triggering sympathetic nervous system activity (autonomic nervous system).
  • Biology isn’t everything – effect of stooge (label: anger/euphoria) and information (explanation).
  • Typifies physiological approach to research as uses lab experiment, collects quantitative data [although also some qualitative, which is unusual], strong controls (e.g. standardised instructions), scientific equipment and procedures (e.g. injections) [although use of social setting/a stooge is unusual for physiological approach].
[q]Discuss the advantages and disadvantages of the laboratory experiment using Schachter and Singer’s (emotion) study. [10] [a]Advantages

  • Ps could be misled to reduce risk of demand characteristics, eg Suproxin / vision
  • Possible to manipulate level of knowledge of effects and therefore explanation for bodily condition
  • Possible to manipulate context to produce positive or negative valence to emotions


  • As injections were used, Ps may have assigned feelings to the injection in the ‘suproxin’ condition, so not very realistic
  • The placebo condition may have had an effect (as placebos do)
  • Situation of questionnaire highly contrived, unlike real life
  • Sample very restricted (males, college students and same uni) so findings may not generalise to behaviour of others, e.g. females less aggressive
  • All psychology students so may have had suspicions about the effects, leading to demand characteristics
[q]Evaluate Schachter and Singer (emotion) in terms of two strengths. [10] [a]
  • stooge/use of one-way mirror: limit demand characteristics
  • controls: e.g. for actual effects of adrenalin (informed v misinformed), standardised procedure for stooge
  • ethics: health check
[q]Evaluate Schachter and Singer’s (emotion) study in terms of its validity. [10] [a]
  • validity strengths: lab/scripted e.g. stooge behaviour was consistent so valid comparison between participants and between conditions (many others possible)
  • many controls in design, e.g. different kinds of control groups (ignorant v. informed, placebo v. real)
  • validity weaknesses: may not have felt the situation was real (e.g. questions on questionnaire were excessive) many other points possible
  • findings only based on males so may not apply to females, especially as females respond to emotional situations differently from males.
[q]Evaluate Schachter and Singer’s (emotion) study in terms of its usefulness/applications. [10] [a]
  • useful because could help us to recognise when we are angry because of the situation and therefore moderate our behaviour, could be used to raise mood (e.g. in depressed people) by finding positive situations, or to understand and perhaps control fear in the company of other frightened people
  • not useful because understanding why emotions are contagious doesn’t necessarily lead to being able to manipulate them: it might not work if you did it yourself, it was an artificial setting and may not generalise to more powerful real world emotions of social situations
[q]Use Schachter and Singer (emotion) to evaluate the use of snapshot studies in psychology. [10] [a]
  • strengths of snapshot studies illustrated by being able to collect data in just a few hours, so each person’s reactions would be very similar, e.g. no differences like how things were going on their university course making them more aggressive, reducing extraneous variables between sessions with the stooge
  • also because participants are likely to be similar unlike studies which take a long time when seasonal/generational/cultural differences may influence findings whereas this study’s participants are likely to have all had similar cultural influence, e.g. from trends in violence in current films
  • weaknesses of snapshot studies illustrated by potential lack of generalisibility because situation is time limited so doesn’t reflect real variability, e.g. generally anger ‘mounts up’ over time – sometimes a lot more than the approx. 20 minute exposure to the stooge
  • only one moment in each individual’s behavioural stream. Even though they were comparing manipulation by the two types of stooge, some participants might have been having a “bad day”.

Matching Exercise: Euphoria Condition

Matching Exercise: Anger Condition

Teaching Resources