Are We Really the
Champions of Reciprocity?
Incomplete Information About
Others’ Behavior Undermines
Cooperation and Reciprocity
Joel Vuolevi & Paul van Lange
Dept of Social Psychology, VU University,
Amsterdam, the Netherlands
13th International Conference on Social Dilemmas,
Japan, Kyoto, 20th – 24th August 2009
The “psychology” of
incomplete information
Complete
Information: “The
other allocated 7
coins out of 10”
100
90
80
Probability
Reciprocity is
a matter of
simple choice
The other’s previous behavior
70
60
Complete
Information
Incomplete
Information
50
40
30
Incomplete
20
Information: The
10
other’s behavior
0
subject to
1
2
interpretations
Reciprocity depends on
inferences regarding
other’s previous behavior
3
4
5
6
7
8
Level of Cooperation
9
10
How do we “fill-in” the missing pieces
of information in others’ behavior?
To start with, how about without having any information
at all – people’s beliefs about other people in general
• People think that others’ behavior stems from selfinterest (Miller & Ratner, 1998)
• People think of themselves as more moral and honest
than others (Allison, Messick, Goethals, 1989, Lange &
Sedikides, 1998)
Global judgments about other people
in general are guided by a belief in the
self-interest of others.
Do global judgments influence
evaluations of concrete behavior?
Under incomplete
information, people fill-in the
blanks of concrete other
person’s behavior with selfinterest: The Dice Rolling
Paradigm (Vuolevi & Van
Lange, EJSP, in press).
The research question
Under no information, people believe that
other people are self-interested
Under incomplete information, the belief in
others’ self-interest distorts judgments of
overt behavior
Does the belief in others’ self-interest
influence the way in which we respond to
others under incomplete information?
No longer the champions of reciprocity?
Coin paradigm: Method
• Sequential task:
1) Other’s allocation
2) Information
3) Estimation
4) Own allocation etc.
• Pps were told that “the
other” had allocated 16
coins
• Pps clicked coins to
see which of them the
other allocated to
oneself or to the
participant
IV: number of coins displayed
• Fair allocations (8/8)
DVs: estimation and allocation
Study 1: Results
With less information
pps underestimate
cooperation and
cooperate less
People reciprocate the
number of coins they
believe they have
received (=perceived
vs. true reciprocity).
Study 2
• Tit-For-Tat (TFT) as the basic strategy instead of the
fairness strategy – provides a more realistic baseline
• A true dilemma – coins worth more for the other person - incentive for cooperation
• A cooperation manipulation - how people respond to
others who are more/equally/less cooperative than the
pps
• Design: 2 (information: low vs. high) by 3 (strategy: TFT2, TFT, TFT+2)
Study 2: DV: Cooperation
• Also with TFT pps
cooperate less in the
low information
condition
• Reciprocity is more
complete in the high
information condition
than in the low
information condition
• Cooperation is
challenging to
communicate under
high level of
incompleteness of
information
Study 2: DV: Person Perception
= impression of benign intent (Van Lange et al, 2002)
• The less information
the more negative
person perception
• The other’s behavior
influence person
perception in the
high information
condition, but much
less in the low
information condition
Conclusions
• Incomplete information is a part of everyday life –
especially when making inferences about others’ behavior
• In incomplete information situations both beliefs and
information influence inferred cooperation
• With low levels of information behavior is guided by selfinterest beliefs, with high levels of information by
reciprocity
• Perceived reciprocity: responding in kind becomes
responding in mind
• Reduced cooperation is rooted in people’s tendency to
underestimate others’ cooperation
Why do we underestimate others’
cooperation?
• My good intentions vs. your bad behavior (Pronin, 2008)
• Behavior is often influenced by unintended errors (Van
Lange et al, 2002) and situational constraints (Jones and
Davis, 1965)
• Not to lose is more valuable than to gain (Kahneman &
Tversky, 1979; Baumeister et al, 2001)
Take Home Message
We truly believe that we are the champions of
reciprocity, but we fail to see if others actually are.
We are not the champions of reciprocity
Through acting upon self-created
beliefs, incomplete information forms
a serious threat to the development
of human cooperation