What are Mood Induction Procedures?
Processes where mood is induced exogenously (by lab experimenters) in participants
Westermann et al (1996)
Different MIP Classifications:
1. IMAGINATION MIP => had to imagine situations that invoked a desired mood, and to intensify this, subjects may be sometimes asked to write a narrative down (e.g. Capra et al.)
- Velten MIP=> asked to read a number of statements that are either positive, negative, somatic or factual to have a neutral group
- Film/Story MIP=> Make them read a narrative or watch a film to stimulate their mood. criticism: cultural specific - have to be careful with subjects used
- Music MIP: listen to a mood-suggestive piece of music
- Feedback MIP- given positive or negative feedback on their performance. can also deceive them (but unethical))
Most widely used technique:
1. Velten MIP (read positive or negative statements that induce mood) - almost 50%
and
2. Film/Story MIP - almost 12%
Findings:
1. Film/Story is the most effective with instruction and also effective without instruction
2. Music is higher if combined with instruction than separately
3. The effectiveness of mood induction proved to be higher for negative than for positive mood
• may be due to the fact that subjects usually enter the experiment in a rather positive mood and that such a positively biased basic mood is harder to enhance than to depress.
Other techniques also include:
Social Interaction MIPs
• Gift MIPs - as a token of appreciation
• Facial Expression MIPs - Subjects are instructed on how to contract and relax different facial muscles to produce a frown, a smile, a neutral face etc.
• Combined MIPs e.g. Velten and Imagination, or Velten and Music
Capra et al (2010)
A) Interested in whether mood affects choices in complex interactions such as auctions
B) Two ways which mood can affect behaviour:
- mood can affect the valuation of object
- mood can affect the behaviour of bidding
C) CONSTRUCTED PREFERENCES HYPOTHESIS: mood affects the way people construct their preferences
D) AFFECT REGULATION HYPOTHESIS: predicts that people who are in a negative mood will take actions (e.g. bid more to acquire the item) to improve their moods, whereas people in positive mood will refrain from acting as a way to prevent changing their situation.
E)
Each session consisted of four parts:
1. demographic questions (including mood state)
2. Mood induction - Imagination MIP - try to imagine an experience of success/failure and then 5 minutes to create a narrative (=> strengthens emotions)
3. Auction –homegrown values auction - same value, no feedback
4. Auction- induced values auction
F) Subjects had to bid for the item and the experimenter ranks the bids and randomly selects
the five highest bidders obtain the item by paying the price of the 6th highest bidder
G) Results
1. Subjects in a good mood overbid by about 11 percent => inefficiencies that result from overbidding - high under positive mood
2. Once compare the induction valuation, weak evidence that positive and negative mood impact WTP as opposed to neutral
- while a neg. mood encourages individuals to alter their current mood to make them feel happy by buying the item therefore higher WTP, negative mood also lowers WTP because of pessimism
=> no change in WTP because of these two opposing forces
=> no mood effects on WTP
Proto et al (2017)
Does mood affect cooperation? Does pre-play communication change things?
The effect of positive mood on cooperation in prisoner’s dilemma
Despite standard dominance arguments we see cooperation in many lab settings
=> analyse the effect of positive mood which can be complex because of two hypotheses:
1. Cognitive hypothesis: people experiencing positive mood are more likely to use less information and avoid systematic thinking - cognitive load reduces cooperation
2. Social preference hypothesis: positive mood produces more open and altruistic behaviour therefore increasing cooperation
Design:
1. mood induction - positive and neutral
2. cooperation task - repeated PD: finitely and infinitely
3. PRE-PLAY COMMUNICATION (with and without)
also other controls for personality, risk attitudes, demographics, etc
2 MIPs:
- Velten: statements inducing a positive and a neutral mood
- Music based on notes that elicit mood
Results:
- Positive mood; cooperated less and significant for pre-play communication as well
- Everything is robust to the inclusion of pre-play communication, to changing the game from infinitely to finite and text analysis reveals that those in a positive mood are more ego-centric which might explain why they cooperate less
