PSY353 Exam 3 study set

What is a game?

More than 1 player

Has moves & strats

Payout depends on moves of players

What is a simultaneous game?

All players move at effectively same time

All players chose their moves w/o knowing other players’ moves

What are sequential games?

Players take turns

Players make moves based on other players’ moves.

What is the prisoners dilemma in strategic form?

A table of payoffs for cooperation or defecting.

Defecting is the dominant strat

What is a dominant strategy?

A specific move that is best for both players regardless of the other players’ actions.

What is a Nash Equilibrium?

Neither player has an advantage to use a different strategy, given what the other player is doing.

Assumption is that players will tend to wind up in an NE.

What is the relationship between dominant strategy equilibriums and Nash Equilibriums?

All dominant strat equilibriums are Nash Equilibriums;

Most Nash equilibriums are not dominant strategy equilibriums

How are Nash Equilibriums (NEs) written?

{row player, column player}

What does is mean to be Pareto efficient?

No other outcome exists that makes one player better off without making another worse off;

There is no other outcome that all players would agree to move to

Is the NE for the Prisoners dilemma pareto efficient?

No; defecting makes one player better while making another worse off.

What makes a game a Prisoners dilemma?

If both cooperate; get the 2nd best outcome

If both defect; get 2nd worst outcome

If one cooperates & the other defects; defector gets the best outcome

What is a coordination game?

A game where each players’ best outcome is to do what the other does.

2 NEs.

For outcomes x (best) & y (worst), what are the pareto efficient and risk dominant events?

{x, x} is Pareto Efficient

{y, y} is risk dominant

Why might both people choose the risk dominant option in a coordination game?

Both choose the safe option if they are not confident in their partner.

What is a chicken game?

An anticoordination game; can win by binding commitment before the game begins

What are ways to win the game of chicken?

Precommitment; limiting options; must announce precommittment.

What is a pure strategy?

Players strat is to choose a certain move

What is a mixed strat?

Players strat is to choose a move at random with certain probabilities.

What is a pure & mixed strat NE?

NEs where both players are playing a pure/mixed strat.

What is the iterated Prisoners Dilemma?

Defector vs cooperates in a series of games;

Tit for tat: does whatever the other player did last round

Defectors have higher win record but lose the overall ternament.

Why do we see cooperation even when it is better to defect?

Cooperators do better because people choose not to cooperate with defectors.

What are the best strategies for the single and iterated prisoners dilemma?

Single: defect

Iterated: Tit for Tat strat

What does it mean to be game theoretic?

Each player is picking the option that gives themself the best outcome.

What are the assumptions of backwards induction?

Everyone is being game theoretic; picking the best option for themself

Everyone is using backwards induction

Everyone knows everyone else is being game theoretic

Everyone knows the payouts to everyone involved

Players’ desire is included in the provided outcomes.

What is the guessing game?

Picking a number from 0-100 where the winner is the person closest to 2/3 the average of all numbers in the game.

What is counterintuitive to the guessing game?

Under Nash Equilibrium, the “answer” would eventually be 0, because of backwards induction.

What is the centipede game?

2 players take turn; each can quit or pass

Money is split between the players and increases every turn

Quitting on one’s turn nets more money that the other player if they also quit.

If the last player to move quits, they get more money than if they pass.

What would game theory say about the centipede game? Why? What do people tend to actually do?

Game theory says player 1 should quit on the first move because they will always end up worse than player 2 at the end of the game.

in reality people tend to let the game go for a bit before quitting; rarely cooperate or defect on first move

Why should one sometimes “burn bridges” when making threats/precommitting in a sequential game?

if one is the 1st player, they get to determine the outcome; pre-commit to an event and for the other players hand.

What does incomplete information entail?

1 player lacks knowledge about some aspect of the game;

What is the winners curse?

Highest bid tends to be from people who overestimate the value of a payout.

What are the conclusion for lacking information?

Info: less likely to overbid if knowing true worth of an item

Communication: Profit can only be k when people can communicate
No win: sometimes one needs to win auctions even if one knows about the winners curse.

What does the social exchange game entail?

3 players; 2 confederates; 1 fair, 1 unfair & player

Display reported who would be shocked.

What does the social exchange game reveal about fairness/punishment?

Activation of same brain areas when the fair player was shocked & when shocked themselves (empathy)

Women felt experienced less activation when unfair player was shocked; men expressed none

Increased activity in NA for men when unfair player was shocked.

Why may punishment be fun?

Desire to punish rule breakers or uncooperative peers.

What is the ultimatum game?

2 players are offered to split something;

Proposer can propose the split

Responder can accept or reject proposal

If they accept; split

Reject; both get nothing

What does game theory say about the ultimatum game? Why? What actually tends to happen?

Game theory says proposer should propose the smallest amount possible because the responder should accept because they still gain.

In actuality, 50/50 split

What are the true rates for the ultimatum game?

50/50 split

Average proposal is 30-40%

Average acceptance around 20%

Not true cross-culturally

What is the backwards induction for the ultimatum game?

Proposer thinks responder is game theoretic

Proposer knows responder won’t take small amounts; so should offer more

It is in the interest of the responder to not accept small amounts.

What is revealed about activity in the brain & the ultimatum game?

Anterior insula activity for unfair offers from humans but not computers

More activation = less likely to accept

Activity in DLPFC to unfair offers

Why may responders refuse?

To tell proposer their proposal was unacceptable

Refusal to accept smaller offers benefits them

Proposers unwillingness to make small offers benefits them

What is Utalitarianism?

The morally right action is one that has the expectation of bringing the most overall utility; that which brings about the most good for moral philosophy.

What is Consequentialism?

Judge morality of an action based on the outcome; ends justify the means only if they create the most utlity.

What is Deontology?

Morality of an action should be judged based on ethical rules/principles.

What does Utilitarianism and Deontology say about the crying baby dilemma?

Utilitarianism: Killing baby for the sake of others is the best outcome

Deontology: Don’t kill baby; unethical.

What does Deontology say about progressive taxation?

People have right to money; obligation to help others

What does Utilitarianism say about progressive taxation?

Unclear which provides most overall utility

Diminishing marginal utility argues for progressive tax;

But taking too much may take away motivation for hard work

What is the actual reality of Utilitarianism & Deontology?

Very few strictly follow them.

What does fMRI studies reveal about the trolly/bridge problems?

Trolly = Impersonal: activation of emotional areas

What do personal/impersonal moral problems indicate for time-based responses?

Personal moral decisions took longer when appropriate

Impersonal moral decisions took about the same time regardless of response

What brain region was activated when making the utilitarian choice?

DLPFC

Damage to the VMPFC resulted in what moral decision?

More likely to choose utilitarian responses.

What does the conflict between consequentialism and deontology reflect?

Deeper brain conflict; emotional vs cognitive responses.

What does normative theory say about caring for others? What actually ends up happening?

Normatively, we should care about each life equally.

In reality, after a certain amount, we stop caring about the losses of lives.

How is psychic numbing explained?

Limitation of the mind: can’t emotionally handle/conceptualize emotional costs.

How is compassion collapse combated?

With the identifiable victim effect.

What does the identifiable victim effect entail?

People are more willing to help a singular person, rather than a group of people.

What is the drop in the bucket effect?

People are less willing to help if their overall contribution is perceived as inconsequential; thinking about the people who have not been saved makes one feel bad.