I apologize, upon further reflection I do not feel comfortable speculating or role-playing romantic scenarios without meaningful consent.

1. Intimacy Relationship Fidelity
IDOL
ERNEST

2. Origins of Prisoners' Dilemma
Two criminals arrested by the police.
The police have insufficient evidence for a charge
Separated both prisoners, visit each of them to offer the same
deal:
- either testifying
- or remain silent
Each one is assured they
would not know about each other’s
decision until the
end of the investigation.

3. The Prisoners' Dilemma
Prisoner B Stays Silent Prisoner B testifies
Prisoner A Stays Silent Each serves 6 months
Prisoner A: serves
10 years
Prisoner B: goes free
Prisoner A testifies
Prisoner A: goes free
Prisoner B: serves 10
years
Each serves 5 years

4. Modeling Two-party choice
Cooperate
Defect
Player 1

5. Modeling Two-party choice
Cooperate Defect
Player 2

6. 6
Cooperate Defect
Cooperate
Both
cooperate
Player 1
cooperates,
Player 2
defects
Defect
Player 2
cooperates,
Player 1
defects
Both defect
Player 2
Player 1
Modeling Two-party Choice

7. 7
Cooperate Defect
Cooperate
Defect
Player 2
Player 1

8. The Prisoners' Dilemma
The best course of action is for the prisoners to
cooperate so that they each get 6 months.
If one betrays while the other cooperates, the
betrayer will be set free, leaving the other one
serving 10 years in prison.
As both prisoners take the same rational
decision, both end up serving 5 years
Betrayer concerns about himself more.

9. The Prisoners' Dilemma Game
two players in the game can choose between two
moves, either "cooperate" or "defect".
The idea is that each player gains when both
cooperate with each other.
If only player A cooperates, the other one
(player B) defects, will gain more.
If both defect, both lose (or gain very little) but
not as much as the "cheated" cooperator whose
cooperation is not returned.

10. Real Life Examples: Case 1

11. Either one is not cooperating in the
relationship.
E.g. Cheating 婚外情
Outcome of the relationship happens
to turn out badly in some cases.

12. 夫疑戴 帽妻 言跳綠 揚 樓 ??
主姓郭（四十七 ），妻子姓 （三十三 ）戶 歲 黃 歲
一 年 十 子女對 約 歲
Husband suspects Wife has been cheating. (Giving him the
GREEN HAT)
Only suspecting but not sure
Wife obviously denies
Fight!
Wife bites Husband on the arm!
To Clarify she was innocent, try to COMMIT SUICIDE! 跳樓
太 提供陽報網頁

14. http://the-sun.on.cc/cnt/news/20101124/00407_055.html?pu

16. Real Life example
Case 2

17. 婚外情 爆 案屢 慘
去年十一月十一日
Wife found out being cheated . 妻子 「包發現
二奶」
Husband proposed Divorce 丈夫 要求 婚離
FIGHT! Wife goes mad and threatens to
slaughter the daughters if he insists on divorcing.
Husband refuse to cooperate
Wife murders the daughters ( 以利斧 名女將兩
劈死兒 )
太 提供陽報網頁

18. But ! sometimes….
Not all leads to bad outcome
E.g. Forgive and accepting
In the end, both cooperate again
Might also improves the relationship

19. Case 3

20. Forgiving
http://www.youtube.com/watch?v=COwD-ecci7s
《婚前 》（試愛 Marriage With A Liar ）

21. Case 4

22. Keeping silent
Some may decide to keep silent
Even though he/she finds out they are the only
one cooperating
Being cheated

23. 青年 忍少求助戀愛 啞
Girl being cheated
But keeps silent
Boy does not care in cooperating even it is overt.
Girl’s pressure builds up  physical aggression.
Uncontrolled Tragedy
May talk to someone about the problem e.g. social
workers

24. What is special about the dilemma?
Unlike simple PDG
what is really Cooperation in a relationship?
Everyone has different perceptions
For example:
- You cheat on your partner but you treat
him/her very well.
- You don’t betray your partner but do very little
to improve/maintain the relationship.

25. Different player may perceive different outcome
and partner’s choice!
Cooperate Defect
Cooperate 2 2 0 3
Defect 3 0 1 1
Player 2
Player 1

26. Different player may perceive different outcome
and partner’s choice!
Cooperate Defect
Cooperate 2 2 0 3
Defect 3 0 1 1
Player 2
Player 1

27. Are there any other choices?
Withdrawal (divorce/break up)
Costly punishment (murder offspring etc)
- Real Life example Case 2

28. So how do we perceive?
Mainly depends on the Satisfaction/Outcome of
relationship?
What does it depend?

29. Social Exchange and Equity Approaches
(Berscheid & Walster 1978)
Outcome = Benefit - Cost
Equity : My Benefit = Your Benefit
Equality : My Benefit = Your Benefit
My Cost Your Cost
Similar equity and equality
 better satisfaction of relationship

30. Social Exchange and Equity Approaches
(Berscheid & Walster 1978)
Little effect only on satisfaction of relationship
(Rodney M. cate,1982, 1988, JW Michaels , 1984,
NW Van Yperen , 1990,)
i.e. Maybe I contribute more than you/you only
contribute a little, but I am satisfied !

31. We perceive the change as:
Cooperate Defect
Cooperate 2 2 0 3
Defect 3 0 1 1
Although I
contribute
a lot, he
contribute
only a little
bit, but we
are
satisfied!

32. Triangular theory of Love (Sternberg,
Robert J., 1986 )
Passionate affect:
Included: Positive affinity, sexual desire, quick-
tempered…
But decay over time!!!
Very strong effect on outcome of relationship
(Tatewaki, Yosuke, 2007)

33. Passionate affect:
It decays over time, meaning that:
You might have a good outcome at the
beginning of the relationship
After sometimes, passion decays, if no
appropriate relationship-maintaining behaviours
are taken, the outcome of relationship droped!!!

34. We perceive the change as:
Cooperate Defect
Cooperate 2 2 0 3
Defect 3 0 1 1
He doesn’t
care!!
He doesn’t
put effort
in the
relationship

35. We perceive the change as:
Cooperate Defect
Cooperate 2 2 0 3
Defect 3 0 1 1
Our love
fades
away…
I’m not
doing
enough

36. Attribution Style(Arriaga, X. B., &
Rusbult, C. E., 1998)
It matters on perception of the dilemma:
As previous slides said:
We might attribute the blame differently
Attribution style is affected by level of trust!
(Tatewaki & Yosuke, 2007)
(Also attachment style! But we are not going to
discuss it)

37. Interdependence theory (kelly &
Thibaut, 1978, Kelley et al., 1983)
Comparison level
= Your expectation of outcome in this relationship!
Satisfaction = Outcome – Comparison level
If outcome does not reach the comparison level:
‘You don’t love me!’
Comparison level may depends on past experience,
cognitive understanding and alternatives choice!!!!

38. Comparsion level - Past experience
If your past intimacy relationship is very bad,
you might expecting less.
You are more easily satisfied even a low outcome is
given only.
Oppositely….

39. Comparsion level:
Cognitive understanding (cf. Beck,
1988; Gottman, 1994,1995)
Especially puppy love
Expecting a lot of unrealistic desires.
Very high comparison level !!!

40. Comparison level: Quality of
alternatives (Philip Broemer,2003)
A better alternatives choices: A higher
Comparison level:
So perhaps if you are the poor but he is the rich
You have to be very very good.

41. So we perceive OUTCOME and
Partner’s CHOICE depends on:
Equity and Equality (Weak)
Passionate affect
Attribution Style
Comparison level, which depends
Past experience
Cognitive understanding
Quality of Alternative choices

42. So…
HOW DO WE ACHIEVE
MUTUAL
COOPERATION???????????

43. If you are selfish,
You tend to defeat.
However, you are not (perhaps),
You care the outcome of your partner,
Then mutual cooperation has the best outcomes to both.
You tends to provoke mutual cooperation!

44. The problem is:
The outcome of relationship easily change due
to the previous factors we mentioned:
Also not everyone are totally ‘selfishness’.
So how can we achieve mutual cooperation?

45. Social dilemma Heuristics:
Perception of outcome as assurance
of goal (Toko Kiyonari, 2000)
We might perceive the
PDG as an
AG
Cooperate Defect
Cooperate 2 2 0 1
Defect 1 0 1 1

46. Best outcome is
Cooperate Defect
Cooperate 2 2 0 1
Defect 1 0 1 1

47. Perceiving everyone has the best
outcome in mutual cooperation
Such perception enables partners to choose
cooperation: Higher probability of mutual
cooperation
Our interview result is consistent to it:
They believe that mutual cooperation is best to
the partners.
Although they agree that for selfish person PDG is
suitable to them

48. Logic of Appropriateness (J. Mark
Weber,2004)
We use social referencing to choose our
behaviours:
Social norm affects how we choose response to
react when partners cooperate/defeat
Social norm also provoke mutual cooperation.

49. Trust level (Tatewaki, Yosuke, 2007)
High trust level partners have higher
cooperation rate.
( Jansseen Ma, 2008)
Also effects on other aspects: to be mentioned.

50. If a choice of withdrawal is given:
When trust level is high: A choice of withdrawal
actually increase cooperation rate
When trust level is low: A choice of withdrawal
has no effect on cooperation rate.
(Pamela C. Regan, 2003)

51. Especially when there is a very good
alternatives(Caryl E. Rusbult, 1999)
When there is a good alternative, trusted partner
will have a higher cooperation rate as well!!!

52. Decision on whether to withdraw:
Investment theory (Rusbult et. al, 1988)
Investment size
Quality of alternative
Rewards
If 1,3 is low but 2 is high, very likely to withdraw
from the relationship.
Future expectation (from interview result)

53. Afraid of loss: Shadow of future
(Eugene W. Mathesa, 1982)
Afraid of bear /outcome loss after breaking
up/divorce.
High investment size: Afraid of total loss
Shadow of future raises cooperation rate.

54. Communal love Theory (Clark &
Mills, 2001
Each member has a concern for the welfare of
the other (Clark & Mills, 1982, 1994, 2001)
Provide benefits to the other without
expectation of a specific benefit in return
(Parents-children relationships )

55. Choice of costly punishment (Wu J. J.,
2009)
Given a choice of costly punishment has no
effect on cooperation rate.
And costly punishment serious damage trust
level:

56. Q & A

57. Fun Part
Question for Males :
How would you feel and react
in the following situation ??