Chapter 7 True Experiments II
Substantive Theme: Social and Emotional Influence on Thinking and Perceiving
- Emotion can be manipulated in the laboratory. Elegant experimental studies by Paul Ekman and other
researchers have indeed shown that emotions can be covertly induced and reliably manipulated by
specific facial contractions.
- Human face is an exquisite and efficient organ of emotional communication.
- The idea is that the emotional salience of the human face reflects an intricate interaction (statistical)
among distinct features of the face.
- Statistical interactions – It is how different factors, either directly or indirectly, influence experience
example the effect of valium and alcohol when taken together produce feelings of depression but when
taken alone produce very different emotional effects.
- Factorial design – An experimental design in which all conditions of the independent variable are
combined with all conditions of the other independent variable. The main effects of each independent
variable as well as the interaction effects between and among the independent variables can be statically
- Multifactorial design – This design allows for testing of effects of all possible combinations of the levels of
the independent variables on the dependent variable. It provides information as to the main effect of
each independent variable as well as any interactions between and within independent variables.
- All single-factor experiments must incorporate one and only one independent variable with two or more
- In multifactorial designs an altogether new independent variable is devised and incorporated into the
- Example: Mood induction with two levels happy or sad and cognitive exercise also with two levels, verbal
or visual. The two independent variables are mood induction and cognitive exercises. The idea behind the
study is how emotion (mood induction) might influence thinking (cognitive exercise) and whether a
particular mood state might be better for performing a particular cognitive exercise
o Participants would be randomly assigned to one of the 4 experiment conditions: 1) happy
mood/verbal; 2) happy mood/visual; 3) sad mood/verbal; 4) sad mood/visual. For within-subject
multifactorial research design, all participants would run through each of the 4 experimental
o A happy mood improved performance for generating remote verbal associations, a test of
creative problem solving, but it detracts from performance on a visual task that requires
attention to detail.
- Multifactorial research design provides a more realistic model of rich psychological phenomena. It offers
an economical and efficient design to evaluate and to test the separate and joint influences of one or
more independent variables on dependent variables.
- The results from previous experiment show that mood and cognition interact; meaning the influence of
the independent variable of mood induction differed depending upon the level of the second variable.
Notations and Terms
- Factorial experiments are typically designated or identified by a numbering notation. - 2 x 2 factorial design – has two independent variables, with two levels or values. The number of numbers
tells how many factors or independent variables there are, and the number values tell how many levels of
the independent variables.
o A 3 x 4 factorial design indicates two independent variables, one with 3 levels, and other with 4
o The order of the numbers doesn’t make a difference.
o The 3 x 4 design means there are 12 groups and 2 x 2 there are 4 groups.
Theory and Experimentation
- The embodiment of emotion, when induced in human participants in the laboratory by covert
manipulation of facial expression, causally affected how emotional information is processed.
- Theory and experimentation are closely intertwined. Theory guides how an experiment is designed, how
independent variables are developed and manipulated, how dependent variables are measured, and what
specific hypotheses are tested.
A Complex Within-Subjects Experiment
- Reginald Adams and Robert Kleck theorized that eye-gaze direction and facial expressions represent two
distinct and isolable features of the human face, which, among others, may be especially important in
conveying social information.
- Approach-avoidance motivation – A psychological theory that states behavioural cues share information
value as signals of approach, propelling behaviour forward, or conversely, they may fuel avoidance,
triggering inhibition. Confrontation or “fight” conversely, they may fuel avoidance, triggering inhibition,
culminating in “flight” from negative stimuli, of potential danger and threat.
- Anger and direct eye gaze with approach motivation and fear and averted gaze have been associated with
- Social signaling system – facial expressions of emotions and gaze direction operate as social signaling
system that governs our basic behavioural tendencies for approach or avoidance.
Decoding Facial Expressions of Emotion
- We naturally and automatically perceive facial expressions of emotion holistically as messages.
- An experiment; the eye region of the face, one of the key sources of information for decoding emotional
expression, Whalen et al. (2004) compared “eye whites” known as sclera of standardized of fearful eye
whites in comparison to that of happy eye whites.
o Consistent with the findings of Adams and Kleck (2003) Whalen also found that the amygdala of
the human brain to be especially sensitive to fearful white eyes but not to happy white eyes.
o Fearful eye whites are larger than happy eye whites
Devising Independent Variables
- Adam and Kleck (2003) investigated two aspects of the face that they thought would be particularly
important for emotional expression: A) facial muscle contractions that form different emotional
expressions such as fear or anger. B) Gaze direction, such as direct or averted eyes.
- They came up with two hypothesis A) anger faces with direct gaze would be more readily perceived
than anger faces with averted gaze. B) Fear faces with averted gaze would be more readily perceived
than fear faces with direct gaze. - To test their hypothesis they created experimental stimuli to construct facial stimuli that varied in
expression and gaze direction.
- Experimental stimuli – Materials that are used in constructing an independent variable.
- They created 4 types of faces using Photoshop 1) anger with direct gaze 2) anger with averted gaze 3)
fear with direct gaze 4) fear with averted gaze
- Experimental task – A task that participants performed that is used as an independent variable.
- The participants were asked to make speedy judgement whether the faces displayed anger or fear by
clicking left or right on a mouse. They used within-subject design so that all participants received all four
types of faces.
- 2 advantages of using within-subject design in these experiments - Individual differences that could figure
very prominently in processing emotions are automatically controlled. 2 it is more economical than
between subject designs because you need fewer participants.
- The reliability of a test can be increased by adding more items such as they had 240 slides because
disadvantage is that within-subject designs can be limited by small sample size but it is resolved by adding
The 2 x 2 Design
- Their experiment manipulated two independent variables: emotional expression and gaze direction. Each
independent variable had two levels with anger or fear faces the two levels of emotional expression and
direct averted eyes the two levels of gaze direction.
- The dependent measure was response time in milliseconds for judging faces as expressions of either
anger or fear.
- 2 x 2 factorial design produced for combinations of conditions; anger/averted gaze; fear/direct gaze
faces; anger/direct gaze faces, and fear/averted gaze faces.
- Column means - the response times to faces with direct gaze and averted gaze because they are
calculated by averaging the columns of the table. The averages across levels of one independent variable.
(Vertical line). It means that faces with direct gaze were responded to as quickly as faces with averted
- Row means – The response time to anger expression and fear expression because they are calculated by
averaging the rows of the table. (horizontal line) It means that anger faces were resp