This document describes Study 2 of a research project on social influence and optimism. In the study, participant pairs will play an estimation game and receive bogus feedback about their partner's confidence levels. Researchers hypothesize that participants will update their estimates more when their partner agrees and is confident, and that brain regions tracking a partner's rating will be more active for confident versus unconfident ratings. The study uses a 2x2 design to test the effects of partner agreement (agree vs. disagree) and confidence (confident vs. unconfident) on participants' willingness to change their bets.

1. Optimism under Social Influence
Lab Meeting - 2.11.2012

2. Under Social Influence:
Overview
 Study 1 – “We are in this together”
Does working together make us more optimistic about
the outcomes than working on your own?
 Study 2 – “Listen in”
Does learning about another person’s confidence in
their predictions alter our confidence?

3. Study 2:
“Listen in”
 Participants will be tested in pairs
 Play an estimation game
 Bogus interaction between partner
 Design
 2 (agree versus disagree) x 2 (confident versus unconfident)
 Procedure
 On each trial they make over/under predictions about the value of
different property items (e.g., higher or lower than £1.000.000?)
 How much are you willing to gamble on your answer?
 2/3 of trials: Seeing partner’s prediction (disagree versus agree)
and gamble
 Opportunity to alter their gamble

4. Update Change
gamble:
25p
+
+
Your
Gamble:
30p
Participants can gamble
More than between 1p and 100p.
£1.000.000
?

5. Update Change
gamble:
70p
Partner’s
gamble:
75p
Partner
Your
Gamble:
30p
More than
£1.000.000 Discrepancy
?

6. Update Change
gamble:
29p
Partner’s
gamble:
15p
Partner
Your
Gamble:
30p
More than
£1.000.000 Discrepancy
?

7. Update Change
gamble:
28p
Partner’s
gamble:
75p
Partner
Your
Gamble:
30p
More than
£1.000.000 Discrepancy
?

8. Update Change
gamble:
40p
Partner’s
gamble:
15p
Partner
Your
Gamble:
30p
More than
£1.000.000 Discrepancy
?

9. Hypotheses
 Comparatively great update when people agree
and partner is confident
 Neural regions will be more sensitive to
tracking partner’s rating when these ratings are
confident