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Do you think what I think you think? Strategic and evidential reasoning in context

Dr. Michelle CowleyDr. Michelle CowleyCentre for Socio-Legal StudiesCentre for Socio-Legal StudiesWolfson Fellow Research SeminarWolfson Fellow Research Seminar

January 27th 2009

How do people represent evidence in mind?How do people represent evidence in mind?

Why is mental representation important?Why is mental representation important?

Exp 1: Exp 1: The selfThe self

Exp 2Exp 2: : The expertThe expert

Exp 3: Exp 3: The opponentThe opponent

Exp 4Exp 4: : The anchorThe anchor

Exp 5Exp 5: : The otherThe other

DiscussionDiscussion

OverviewOverview

Mental Models as Mental Mental Models as Mental RepresentationsRepresentations

Mental Modelso Principle of truth

o Principle of parsimony

o Principle of consistencyof consistency

o Alternative possibilities

o Qualitative weighting

Weighting Models

Principle of independent weighting

Principle of inclusiveness

Principle of quantification

=> Probabilistic mental representation

Johnson-Laird (2006), How people reason

(e.g., Oaksford & Chater, 2007)

o Confirmation bias and 2-4-6 (the formation of reasoning Confirmation bias and 2-4-6 (the formation of reasoning psychology)psychology)

o Discover a rule that the number sequence 2-4-6 conforms to:Discover a rule that the number sequence 2-4-6 conforms to:

o Usually generate the hypothesiUsually generate the hypothesis s ‘even and ascending in twos’.‘even and ascending in twos’.

o And And positive tests positive tests such as: 10-12-14, 16-18-20, 22-24-26…such as: 10-12-14, 16-18-20, 22-24-26…

o Experimenter responds yes each time… Experimenter responds yes each time…

o The tests fit the true rule, which is in fact ‘any ascending number The tests fit the true rule, which is in fact ‘any ascending number sequence’. sequence’.

o Simultaneous correspondence with the hypothesis and the truth. Simultaneous correspondence with the hypothesis and the truth.

o Unless a Unless a negative test (i.e., refutation)negative test (i.e., refutation) of the hypothesis (1-5-of the hypothesis (1-5-9), which is consistent with the truth but inconsistent with the 9), which is consistent with the truth but inconsistent with the hypothesis is prompted, then they will never discover the truth. hypothesis is prompted, then they will never discover the truth.

The SelfThe Self

Figure 1: Embedded false hypotheses in the 2-4-6 task and Figure 1: Embedded false hypotheses in the 2-4-6 task and prejudiced thinking (Wason, 1960).prejudiced thinking (Wason, 1960).

The logic of biased thinking in the 2-4-The logic of biased thinking in the 2-4-6 task6 task

U

Even, 2, Asc

True rule

U

Jewish stereotype

Anne Frank

Embedded false hypothesis in the 2-4-6 Task:

Embedded false hypothesis in stereotypical thinking:

My hypothesis, Your hypothesisMy hypothesis, Your hypothesisParticipants:Participants:oThirty-Two members of the publicThirty-Two members of the public

oThere were 23 women and 9 men There were 23 women and 9 men (age range: 20 to 75 years; mean = (age range: 20 to 75 years; mean = 51 years). 51 years).

oNo participants had taken courses No participants had taken courses in the philosophy of science.in the philosophy of science.

Design & Procedure: Design & Procedure: o2x1 (2x1 (YourYour hypothesis is ‘even hypothesis is ‘even numbers ascending in twos’; numbers ascending in twos’; Peter’sPeter’s hypothesis is ‘even numbers hypothesis is ‘even numbers ascending in twos’)ascending in twos’)

oRecording booklet (triples, positive Recording booklet (triples, positive and negative tests and expectancies) and negative tests and expectancies)

o20 minutes on average20 minutes on average

Cowley & Byrne (2005), Cowley & Byrne (submitted)

020406080

100

Peter'sHypothesis

YourHypothesis

Positive testsNegative tests

P < .01

020406080

100

Peter'sHypothesis

YourHypothesis

Abandonedfalsehypotheses

P < .01

a b c d e f g h

8

7

6

5

4

2

1

3

Figure 4: A representation of a chess board middle game, in which it is white to play.

The ExpertThe Expert

Ps. Ten novices and ten Masters

Design: 2x2 (expert lev * normal/random position)

Materials: Dynamic equilibrium (n = 6)

Procedure: Think aloud + retrospective evaluation(3 min per position), recorded

Protocol Analysis: Segmentation

Cowley & Byrne (2004), Cowley & Byrne (in revise & submit, Cognitive Psychology)

Fig 5: A subsection of a grandmaster’s evidence search treeFig 5: A subsection of a grandmaster’s evidence search tree

Mental SimulationMental Simulation

Bc3

RetrospectiveEvaluationStarting

PositionNode

Terminal Node

Possible Refuting Evidence

Qg2 Rxa3 bxa3

f5 gxf5

-

- Nxc3

Cowley & Byrne (2004), Cowley & Byrne (accepted, Cognitive Psychology)

Experts’ evaluation of evidenceExperts’ evaluation of evidence

Table 1: The nine possible hypothesis types based on the subjective and objective evaluations of move sequences

Retrospective evaluation Objective evaluation by Fritz by chess player Positive (+) Negative (-) Neutral (=)_____________________________________________________________________

Positive (+) +/+ +/- +/=

Negative (-) -/+ -/- -/=

Neutral (=) =/+ =/- =/=______________________________________________________________________

Key: '+' refers to a positive evaluation, '-' to a negative one, '+/-' means the player’s evaluation was positive and the program’s evaluation was negative.

Expert knowledge representation Expert knowledge representation facilitates evidence evaluationfacilitates evidence evaluation

0

10

20

30

40

50

60

70

80

90

100

Confirmationbias

Refutingthinking

MastersNovices

Normal positions

0

10

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30

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50

60

70

80

90

100

Confirmationbias

Refutingthinking

MastersNovices

Randomised positions(p <.001) (n.s.)

2-4-6 again: The opponent control 2-4-6 again: The opponent control conditioncondition

0102030405060708090

100

Noopponent

Opponent

PositivetestsNegativetests

0102030405060708090

100

Noopponent

Opponent

Negativefalsifying

Negativeconfirming

Chi2 s (p < .05).

Cowley & Byrne (2005), Cowley & Byrne (submitted)

Knowledge of previous convictions (one; two; none):David Baxter had previously served a three year sentence for

being physically abusive towards an ex-girlfriend’s three year old girl in 2003.

Please answer the following questions: Q.1 Please tick whether you think:

David Baxter is guilty __ David Baxter is not guilty __

You cannot decide __

Q.2 On a scale of 1 to 10, circle the number that you think best reflects how guilty you think David Baxter is…

The anchorThe anchorExample PC and child protectionExample PC and child protection

• Seventy-two participants, 24 men and 48 women. Age range 18- 53years, mean 22.4years

• Design 3 x 2 between subjects (left-handedness, right-handedness, no handedness) x (previous conviction, no previous conviction) [6 conditions]

• Materials: The same scenario and measures either with or without a previous conviction and sort of handedness:

• Forensic evidence showed that the blow was delivered by a left-handed person. David Baxter is left-handed

or

• Forensic evidence showed that the blow was delivered by a right-handed person. David Baxter is right-handed

PC and forensic evidencePC and forensic evidence

Figure 9Figure 9: The number of jurors from a jury (n = 12) who : The number of jurors from a jury (n = 12) who chose ‘guilty’, ‘not guilty’, or ‘cannot decide’.chose ‘guilty’, ‘not guilty’, or ‘cannot decide’.

PC and forensic evidencePC and forensic evidence

0

2

4

6

8

10

12

Control RH LH PC PCRH PCLH

Guilty

Not guilty

Cannot decide

Cowley & Colyer (accepted, Psychology, Crime, & Law )

Figure 10Figure 10: The proportion of positive evidence statements generated : The proportion of positive evidence statements generated in the absence and presence of a similar prior conviction.in the absence and presence of a similar prior conviction.

PC and confirming evidencePC and confirming evidence

0%5%

10%15%

20%25%30%

Control RH LH PC PCRH PCLH

Control

RH

LH

PC

PCRH

PCLH

Cowley & Colyer (accepted, Psychology, Crime, & Law )

Figure 11Figure 11: The proportion of alternative possibilities indicative of innocence : The proportion of alternative possibilities indicative of innocence generated in the absence and presence of a similar prior conviction.generated in the absence and presence of a similar prior conviction.

Suppression of alternative Suppression of alternative representationsrepresentations

0%5%

10%15%

20%25%30%

Control RH LH PC PCRH PCLH

ControlRHLHPCPCRHPCLH

Cowley & Colyer (accepted, Psychology, Crime, & Law )

o Role-play experiment (Galinsky et al., 2008)Role-play experiment (Galinsky et al., 2008)

o Twenty groups of two participants each Twenty groups of two participants each

o Volunteered for a classroom negotiation skills exercise. Volunteered for a classroom negotiation skills exercise.

o Ten groups each were randomly assigned to the imaginary Ten groups each were randomly assigned to the imaginary Plutats and Camtas societies. There were thirty-five women Plutats and Camtas societies. There were thirty-five women and seven men (mean age = 21.03 years). and seven men (mean age = 21.03 years).

o This exercise was designed to be analogous to N. Ireland. This exercise was designed to be analogous to N. Ireland. Plutats were analogous to Protestants and Camtas were Plutats were analogous to Protestants and Camtas were analogous to Catholics. analogous to Catholics.

o The students were not told that their situation reflected N. The students were not told that their situation reflected N. Ireland.Ireland.

The other: Imaginary societiesThe other: Imaginary societies

o Thus, the Camtas groups received the following Thus, the Camtas groups received the following instruction scenario (and the Plutats received identical instruction scenario (and the Plutats received identical instructions with the words Plutats and Camtas in the instructions with the words Plutats and Camtas in the opposite positions in their text):opposite positions in their text):

o Your task today is to negotiate a ceasefire on behalf of Your task today is to negotiate a ceasefire on behalf of your people the Camtas. You must negotiate this your people the Camtas. You must negotiate this settlement with the Plutats. Both of you have been settlement with the Plutats. Both of you have been fighting over the same piece of land for many years. Both fighting over the same piece of land for many years. Both of you have a similarly sized population. The Plutats of you have a similarly sized population. The Plutats have continuously terrorised your society and they have have continuously terrorised your society and they have been responsible for over 3,000 civilian deaths in the been responsible for over 3,000 civilian deaths in the past five years. You have used the military strategies of past five years. You have used the military strategies of assassination and mass bombing of civiliansassassination and mass bombing of civilians..

o Several questions to answer both before and after they Several questions to answer both before and after they received the envelope randomly assigning them to plutats received the envelope randomly assigning them to plutats and camtas groups.and camtas groups.

Procedure and MaterialsProcedure and Materials

accepted pending revision, e-Journal Series

Who should ceasefire first?

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both them us

Res

pons

e pe

rcen

tage

Before envelope

After envelope

Who should rule?

0

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100

equal us them

Res

pons

e pe

rcen

tage

Before envelope

After envelope

The Camtas discover that they are the landowners

The Plutats discover that they are the terrorists

o People tend to search for and evaluate positive instances People tend to search for and evaluate positive instances more favourably than negative instancesmore favourably than negative instances

o They can represent and appropriately evaluate opponent or They can represent and appropriately evaluate opponent or ‘other’ thinking when they have the domain knowledge to do ‘other’ thinking when they have the domain knowledge to do so.so.

o Preference for consistencies rather than inconsistencies.Preference for consistencies rather than inconsistencies.

o Even whey they try hard to represent what others think they Even whey they try hard to represent what others think they often cannot help but see through their own negative lenses often cannot help but see through their own negative lenses of what the other may be thinking (e.g., Epley et al., 2006)of what the other may be thinking (e.g., Epley et al., 2006)

o Question of motivated reasoning is currently being Question of motivated reasoning is currently being investigated (ESRC grant 2008/2010 Role of Intent in Legal investigated (ESRC grant 2008/2010 Role of Intent in Legal Contexts). Contexts).

General conclusionsGeneral conclusions

o DNA evidence and mental representation vs DNA evidence and mental representation vs quantifiable probative value (experiments in progress) quantifiable probative value (experiments in progress) and large funding proposal planned.and large funding proposal planned.

o Intentionality and representation in legal reasoning Intentionality and representation in legal reasoning (ESRC proposal recently approved). (ESRC proposal recently approved).

o Layered sequences of experiments to build additional Layered sequences of experiments to build additional complexity into the experimental frameworkcomplexity into the experimental framework

o Group deliberation versus individual deliberation with Group deliberation versus individual deliberation with video-data methodologies- seed funding applied for.video-data methodologies- seed funding applied for.

o Developing the theory of mental models for legal Developing the theory of mental models for legal reasoningreasoning

Future directionsFuture directions

Funding thanks: Funding thanks: The Irish Research Council for the Humanities The Irish Research Council for the Humanities and Social Sciences, The Trinity Trust, Trinity College Dublin, and Social Sciences, The Trinity Trust, Trinity College Dublin, The University of Southampton Grant for New Researchers, and The University of Southampton Grant for New Researchers, and the Socio-Legal Studies Association for funding.the Socio-Legal Studies Association for funding.

Research assistance thanks: Research assistance thanks: Laura Pennicott, Juliette Colyer, Laura Pennicott, Juliette Colyer, Avanti Perera and Paul Honey for research assistance. Avanti Perera and Paul Honey for research assistance.

Thank youThank you