1. Group Affiliation and “Altruistic” Punishment ：Who provides “altruistic” punishment?
Kazumi SHIMIZU/Daisuke UDAGAWA
Waseda University
21 COE-GLOPE
“Social Foundations of Fairness” Program

2. Cooperation and Punishment
In the social dilemma,
Cooperation concerns a first order social dilemma,
Punishment concerns a second order social dilemma.
Public Good
・Cooperation
・Punishment
Provision Problem

3. Resolution of Provision Problem
Among related actors
Kin selection (Hamilton[1964])
Reciprocal Altruism (Axelrod&Hamilton[1981], Trivers[1971])
Among unrelated actors　(but the repeated dyadic interactions is possible)
Indirect reciprocity (Alexander[1987], Nowak&Sigmund[1998])
Group Selection (Gintis[2000], Bowles[2004])
Cultural Group Selection (Henrich&Boyd[2001]).
　　These hypothesis are coherent with evolutionary biology, because they suppose that the altrustic behavior contributes to altrustic persons’ “fitness” as a result

4. Puzzle: (Pure) Altruistic Behavior
　 Altruistic Behavior ∋Cooperation and Punishment provided in a situation where any reciprocal benefit can not be expected by participants.
　　← “Altruistic motives” (Baston[1987])
　　← “Minimal group　paradigm”(Tajfel&Turner[1979])
　　These hypothesis are contested by “Bounded generalized reciprocity” (Yamagishi et al[1999]): Expectation of reciprocity (even if there is not such possibility objectively).
⇔　Evolutionary biology

5. Altruistic Behavior is driven by what?
Our hypothesis
By psychological mechanisms that are adaptive in the EEA
　we are remariking “Normative Sentiments” (Fairness, Trust, Sympahty, etc) ,
following Cosmides/Tooby[1989] and de Waal [1996],

6. Classification of the subjects①
Prior to the experiment, subjects were classified by their recent scores of their “sentiment” indices: general trust scale, trust care scale (developed by Yamagishi & Yamagishi [1994]), self-fairness scale, emotional sympathy scale, perspective taking scale, etc.
Example:
- General Trust : “Most people are basically honest”…
- Self-Fairness: “I always try to act fairly”…
- Emotional Sympathy: “When I see someone hurt, I usually stay calm”…
Perspective Taking: “ When I make a decision, I try to think of the opposite perspective of mine”…

7. Classification of the subjects②
General trust scale consists of 6 questions, trust care scale of 6, self-fairness scale of 6, emotional sympathy scale of 10, and perspective taking scale of 6*.
Each one is interval scale of 7 levels and α value of each aggregated scale is beyond 0.8.
480 under graduate students (male=321, female=154）. .
Constructing subjects pool in Waseda University (N=320), we have sorted them according to these scores.
*Since 2003, the α value is stable.
*Besides these scales, we have “retaliation (negative reciprocity)” scale and “mutuality (positive reciprocity)” scale.
This kind of “sorting experiments” have just begun recently (see Maccabe and al. [2004]).

8. Objective
Verification: Group effect (including “In-group favoritism”) on cooperation and punishment does not occur in a situation where any reciprocal benefit can not be expected by participants.
Prediction : Altruistic punishment is provided only to the degree that it is based on a specific “normative sentiment”: fairness.
Subjects are 47 undergraduate students of different “Gakubu (College)” of Waseda University.

9. Basic Design of Experiment
This experiment consists of two stages: first is a gift-giving game, second is a treatment with punishment opportunity.
“Stranger” treatment: anonymity of subjects are perfectly assured: they don’t meet each other neither “before” nor “after” experiment.
One-shot situation : In the each first stage, only at the end of the stage, the subjects are informed about the individual contributions and the monetary profit of the other group members; about the second stage, they are told that the punishment can be done only once and this is the last stage.
⇒No　possibility of reciprocal benefit!
⇒Rationally speaking, no cooperation and no punishment is the dominant strategy!
According to the traditional economics, the no-punishment is the most rational and dominant strategy. But in sharp contrast to this prediction, powerful motives drive the punishment.

10. No-Grouping Condition: Random matching Grouping Condition:
Grouping by “Gakubu(College)”
Gift-Giving game
endowment=150yens
Gift-Giving game
endowment=150yens
Punishment Opportunity
Punishment Opportunity
Questionnaires
Questionnaires
・Within-subjects plan
・Alternative Order

11. Punishment Opportunity
The participants pay from their own earnings to punish others participants: punishment is costly.
The same cost of punishment is subtracted from the earnings of the punished participants by the experimenter (cost/benefit factor is 1).
They can punish both in-group players and out-group players

12. Information conditions
Pariticipants know well that they can not expect any reciprocal benefit from their (altruistic) behavior.
They are informed that they play this game in a 4-persons group, who do not know each other. In reality, all of them play this game with a computerized program.
After their 5 times decisions in the gift-giving game, the subjects are informed about the individual contributions and the monetary profit of the other group members. This information about the others’ “individual contributions” is artificially made identical for all of the subjects.

13. ID
Sum of Gift
Cooperation Rate
Profit

14. Result 1
In both condition (No-Grouping Condition and Grouping Condition), comparing “in-group” situation and “out-group” situation, there is not any significant difference about the cooperation rate and the mean of punishment cost against free-rider.
⇒No significant “group” effect.
This result contests “Minimal group paradigm”,
yet it follows “Bounded generalized reciprocity” and evolutionary biological knowledge.

15. Mean of Punishment against Free Rider:T-test
In-Group
Out-Group
No-Grouping
①16.4 yens
(Sd=32.2)
②18.6 yens
(Sd=35.2.4)
Grouping
③17.7 yens
(Sd=38.6)
④13.5 yens
(Sd=36.3)
No significant difference
－between ① and ③, ② and ④ (between No-Grouping and Grouping condition).
－between ①and②, ③ and ④ (between In-Group and Out-Group condition)

16. Mean of Cooperation Rate
In-Group
Out-Group
No-Grouping
2.06/5
(Sd=1.66) ∅
Grouping
2.21/5
(Sd=1.77)

17. Result 2
Even in this situation, there are participants who punish free-riders.
Altruistic punishment is correlated significantly with their “normative sentiment”: Fairness.
Higher the fairness, more severe the punishment.
Their punishment is independent of group conditions : （No-Grouping/Grouping condition) ×(In-Group/Out-Group condition).
Fairness correlates weakly to cooperation rate
(Coefficient = .209, p < .05)

18. Correlation between “Fairness” and Punishment
Sum of Punishment
against Free-Rider (Total)
against FR (In-Group)
against FR (Out-Group)
“Fairness” sentiment
0.365**
0.413**
0.386**
** p < 0.01 (Spearman’s correlation coefficient)

19. Result 3
Supportive Motif : “Suppose there is a person who punish free-riders. How strongly did you intend to support him/her financially?”( interval scale of 7 levels ).
Cooperation rate correlates significantly to this level (p <.01).
⇒ High cooperative persons are more willing to support altruistic punishment.
Fairness also correlates significantly to this level (p <.05).

20. between Cooperation rate and Supportive Motif
Correlation
between Cooperation rate and Supportive Motif
Supportive Motif
Cooperation rate
0.421**
“Fairness” sentiment
0.218*
** p < 0.01 , *p<0.05
(Spearman’s correlation coefficient)

21. Institutional Design
　 If the punishing free-riders can yield a solution of
social dilemma , in our society where the reciprocal benefit is not always ensured, we can emphasize the role of
“institutions” which
－ enhance the “fair-minded person’s” altruistic punishment.
－ enable high “cooperative persons” to support “high fair person’s” punishment.

22. Appendix1:Cooperation and Punishment
The cooperation rate and the punishment cost are correlated weakly at 1% level.
Correlation Coefficient is .274.

23. Appendix 2： Earnings at gift-giving game
Min
Max
Av. Sum Sd
No-Grouping
480
1080
827
195.8
Grouping
784
204.6
・Weak negative correlation between each one’s profit and sum of punishment (correlation coefficient=－0.215, p < 0.05)

24. Appendix3:Punishment Cost
Min
Max
Av. Sum Sd
No-Grouping
N=18 7
300
98.28
29.2
Grouping
N=17
540
98.06
129.6
* Participants who punished free-riders