The document summarizes research on what jurors do with evidence during deliberations. It finds that the best predictor of the final verdict is the distribution of initial individual juror votes. It also finds that judges and juries only agree at chance levels, possibly due to unrealistic standards of proof required by some jurors. Theoretical models suggest that demonstrability of evidence and whether the task is framed as problem-solving or consensus-seeking will impact outcomes. An experiment found that a minority evidence-based position was more influential when more jurors initially supported it and when the minority actively engaged rather than remaining silent. Semantic barriers like evidence alteration were used by majorities to maintain pre-deliberation positions when challenged by minorities.

1. What jurors do with evidence during jury deliberation? Sue Hunter Open University Grant Walker Melanie Lamb

2. Right to trial by impartial jury, protected by law from influence BUT jury deliberation is difficult! have to disagree with each other! Schudson (1997)

3. What do we know? Best predictor of final jury verdict = Distribution of pre-deliberation juror verdicts Ellesworth (1989) Majority influence

4. What do we know? Judge & Jury agreement on who should be found guilty chance levels! Kalven & Zeisel (1966) 9% cases hung 74% cases Judge and juries agree 17% cases : 57% judge ►likely convict / jury ►likely acquit so agreement for these 1083 cases at chance levels Criticism : judge - hindsight bias Cameron and Tinsley (2001) Interviewed judge before jury verdict for 48 jury trials agreement 50% - no better than chance.

5. Explanations for lack of agreement judge & jury 1. Genuine leniency bias nullification by a jury - societal correction irrespective of what law says? 2. CSI effect Unrealistic reliance on the infallibility of scientific evidence ? (Lord Justice Leveson, 2009, “forensics = silver bullet”) 3. Lay perceptions of the law rather than legal definitions of the law? e.g. jurors must be 100% certain of guilt – unrealistic high standard (Ogloff & Rose, 2005) 4. Or is it because the jurors do not understand the evidence?

6. Theoretical models Group Decision making - Process

8. Demonstrability affects outcomes Eureka problem truth wins (1) Lower demonstrability truth supported by one (2) Low demonstrability majority, equi-probability otherwise (3:1 OR 2:2) Complexity judgement comes into play (15!)

9. Levine (1999) Abstract fact-finding Consensus continuum Demonstrability affects outcomes Focus Problem solving No correct answer, achieve consensus Task intellective judgemental Emphasis correct solution thro’ information processing selection of alternatives

11. Theoretical models Minority Influence Moscovici (2000) Majority focus on minority = response bias (consensus reasoning) majority influence as an acceptance Minority focus on information (problem solving) minority influence persistent consistency RESPONSE CONFLICT

12. Theoretical models Moderate motivation High Motivation Minority Central processing of information Majority Heuristic processing of information Focus on others Minority Central processing of information Majority Central processing of information Persuasion & Minority/majority influence Martin & Hewstone (2008) Majority heuristic cues /minority elaborative central processing

13. Theoretical models Social representations Semantic barriers: positioning Moscovici (2000), Gillespie (2008). Core representation contains ‘alternative’ representation Semantic Barriers – distance ‘alternative’ - reduces threat to core representation

14. Research Question Does deliberation behaviour change in the presence of an evidence-based minority? Does deliberation behaviour change if the number of evidence based jurors increases?

15. Approach Process Cognitive Ethology: Kingstone, Smilek & Eastwood (2008). Stability tied to situation emerges when several variables allowed to vary simultaneously. Natural variance measured to reveal key characteristics that emerge when variables are “free to co-occur”.

16. Procedure Relevant Script read judge’s instruction and court transcript individually Convened as a jury (15) Deliberation recorded on an audio digital recorder - transcribed Peripheral evidence (CCTV) at end (unanimous not-guilty ►evidence based minority of 2) Peripheral evidence (CCTV) at start More evidence based guilty verdicts + confederates (unanimous not-guilty ►plurality ►guilty majority)

17. Analysis Number of evidence-based jurors (guilty verdict) Topics discussed & percentage contribution by each juror Identification of semantic barriers Proximity Coefficient analysis

18. 14 11 Juries: peripheral evidence (CCTV) end verdict number Straw poll Unanimous 6 5 Silent minority (1) 4 4 Active minority (1) 2 1 Active minority (2) 2 1

19. What difference did the presence of a minority make? Time on topic Time key witness alterations Unanimous 62% 55% 1 Unanimous 91% 44% 2 Unanimous 83% 11% 10 Unanimous 82% 15% 11 Unanimous 81% 2% 11 Unanimous 83% 24% 17 Silent EB minority (1) 19% 1% 3 Silent EB minority (1) 59% 64% 5 Silent EB minority (1) 38% 41% 12 Silent EB minority (1) 57% 44% 24 Active EB minority (1) 63% 44% 16 Active EB minority (1) 92% 57% 32 Active EB minority (2) 64% 64% 24 Active EB minority (2) 62% 76% 46

20. General Public Unanimous jury

21. unanimous jury

22. JURY 3 2 : 13 Minority = 2 evidence-based guilty

23. Semantic Barrier Analysis Semantic barriers: positioning Moscovici (2000), Gillespie (2008). Representation of the ‘alternative’ within the core To maintain the core representation semantic barriers are used to distance the ‘alternative’ – protects core Identification of semantic barriers e.g. alteration of evidence: “ It is the twelve inch blade, if it was a wee tiny glint how are you going to miss this big whopper of a blade ” Original : ‘7 inch blade’ & ‘glint of metal’

24. semantic barriers identified Coroner ≠ key witness description 6 Driver did it 11 Wild theory generation 13 Ridicule of the minority –emotional pressure 18 Reasonable doubt – redefined 27 Absence of evidence (CSI) 35 Only one witness 36 Discrepancy clothing descriptions (confirmation bias) 57 Insufficient evidence 58 Alteration/denial of evidence to negate key witness 65 Negation of key witness disposition (young, adrenaline) 72

25. Coroner ≠ key witness description (6) 156 Em, the, the witness who saw him being stabbed said that his hand was in the air and it came down upon his chest but the wound was a vertical wound through his rib so that didn’t fit Explanation based reasoning! Coroner (vertical) consistent with key witness (down) – correctly cited but meaning change to be inconsistent.

26. Wild Theory (13) 156 But his hand could have been up in the air calling for help and he could have put his hand on to try and stop the bleeding or something and the victim has fallen, he’s maybe got scared and ran away Explanation based reasoning! An alternative story generated to explain evidence

27. Reasonable Doubt (27) 73 I mean a lot of the points are valid, but there’s a doubt in my but there’s a doubt in my mind that she 100% saw exactly what happened so you can’t find him guilty 98 I don’t know I wasn’t like a 100% sure Unrealistic expectation: reasonable doubt redefined as 100% sure Points made by an evidence-based juror are accepted as valid, but despite evidence pointing to guilt the non-evidence based juror does not accept the alternative representation. Reasonable doubt (redefined as 100% sure) is ‘used’ as a semantic barrier to distance the alternative & protect the core representation of not-guilty.

28. Absence of evidence - CSI effect (35) 31 .. for guilty you need to have like the murder weapon and some kind of actual solid evidence rather than just a witness statement 73 ... maybe if they found the weapon he’s be guilty you know if they got DNA from it 48 He’s not on camera footage either Absence of ‘concrete’ evidence is used as a semantic barrier to maintain not-guilty position. Negative reasoning was common.

29. Negation of Key Witness (72) 64 so she can’t have witnessed it properly whilst mucking about with her clips Note original : “ As I stood up I saw a man jump from the side door of the van” The original evidence has been elaborated on so that it discredits the key witness.

33. Guilt Not-Guilty Correct evidence .97 .98 .98 .95 .92 .99 Incorrect evidence Alteration of evidence to negate key witness testimony Majority pressure Response to verdict choice Only minority guilty verdicts associated with correct citation of evidence

34. Response to incorrect evidence Alteration of evidence negates key witness .96 Alternative story generation Confirmation bias .95 .95 MAJORITY MINORITY correct evidence 100 Incorrect evidence story correction evidence correction .95 .95

35. Response to ridicule Alteration of evidence negates key witness .99 Negation key witness’s disposition confirmation bias to negate key witness .99 .98 MAJORITY MINORITY Restate correct evidence .99 personal ridicule of minority Only one witness .95 Correct inferences .97

36. Reasonable doubt Responses to reasonable doubt Minority remain with the evidence but the majority do not correct evidence MINORITY MAJORITY .97 Guilt .95 Evidence-based inferences .96 absence of a weapon .97 alteration of evidence negates key witness .96 denial of evidence .96 alternative story generation .95 negation of key witness’s disposition .93

39. Juries: peripheral evidence (CCTV) start Jury no Number of members confederates Jurors GUILTY Evidence based Verdict change Start split (G;NG) Include any confederates Final jury verdict split G/NG Jury verdict Majority Not-guilty juries 1 15 0 1 5 change to NG 6:9 1:14 not guilty 12 15 0 2 1 changes to NG 3:12 2:13 not guilty 4 15 2 3 3 changed to NG before poll 2:13 2:13 not guilty Plurality juries – near equal split 5 15 2 3 2 changed to G before poll 7: 8 7:8 not guilty 6 15 3 2 3 changed to G before poll 8:7 8:7 guilty 3 14 1 6 1 changed to G before poll 8:6 8:6 guilty Majority Guilty juries 9 13 5 4 0 9:4 9:4 guilty 10 14 6 4 0 10:4 10:4 guilty 11 12 7 1 1 changed to guilty 8:4 9:3 guilty

40. Juror free recall: number of items (total = 30) / juror verdict Jury 4 – Majority not guilty Jury 5- Plurality Jury 9- Majority guilty Non-evidence based verdicts Not guilty Not guilty confusion Guilty Evidence based verdicts Guilty Not guilty No relation between juror verdict & number of items recorded Jurors introduced items in the jury that were not in their free recall Cannot use items recorded in free recall as measure of evidence recall

42. Jury 1 BETTER UNDERSTANDING 1G:14NG 14 items/ 4 corrections 5 stated / 4 negate guilty Jury 12 POOR UNDERSTANDING 2G:13NG 13 items/ No corrections 13 negate guilty Percentage of mock jurors recording item in free recall (prior to deliberation) in relation to how this evidence item was ‘used’ in jury deliberation Stated to CORRECT Jury 7 6G:4NG 10 items 5 stated / 5 negate guilty ID Line-up No mention stated Stated to NEGATE Guilty

44. Interaction: between presence of fabricator & verdict split both juries 4 & 3 contained fabricators Fabricator influenced when not challenged (jury 4) Fabricator did not influence when challenged (jury 3) Both change to NG / fabricator attack No change when support Juror number & percentage contributed to the discussion Jury 4. 42 45 46 47 48 49 50 51 52 53 56 EB G 57 EB G 58 4% 12% 9% 17% 25% 6% 1% 3% 7% 6% 1% Jury 3. 28 EBG 29 30 EB G 31 33 34 35 EB G 36 EB G 37 38 EB G 40 EB G 41 43 EB G 44 9% 19% 11% 11% 4% 22% 19% 9%

46. Discrepancy between clothing Negation key witness’s ability CSI effect Absence of evidence Wild theory explanations Focus on reasonable doubt All juries Number of Semantic barriers in each jury Majority not-guilty Plurality not -guilty Plurality guilty Majority guilty Majority guilty (smaller juries) Semantic Barrier Analysis

47. Discrepancy between clothing Negation key witness’s ability CSI effect Wild theory explanations Focus on reasonable doubt high in 12 & 6 both contained fabricators high in 4 & 5 both plurality juries Not In Majority Guilty juries

48. Proximity Coefficient Analysis Statistical analysis allows identification of cued behavioural responses Also allows identification of ‘end-points’ in deliberation

49. Jury 12- Majority NG (13:2) 167 “ Nobody else agreed with her description” Incorrect evidence Questioning evidence Confirmation bias Negation of Key Witness Reasonable doubt Off-topic

51. Jury 10 Majority guilty 4NG:10G 132 “ I also can’t really see where the attacker comes from and that kinda bothers me as Gillian doesn’t say if he comes from the store, or if he’s on the pavement” Original: “ I saw a man jump from the side door of the van” CORRECT EVIDENCE Negation of Key witness

52. Conclusion Not-guilty verdict jurors: poor evidence comprehension No minority influence from evidence-based jurors As size of evidence-based minority increased the semantic barriers changed: Wild theory ►reasonable doubt ►negation key witness Deliberation was maintaining position

54. Conclusion When the not-guilty faction became the minority – “ you have made some good points, but…..” processed but did not accepted the guilty argument

55. Conclusion Relation to theoretical models: Decision-making process models – demonstrability Truth supported by one did not win Minority Influence/majority influence Persistent consistent minority did not influence Non-evidence based majority influence as acceptance Non-evidence based majority focus on minority (stigma) Persuasion/minority-majority influence Non-evidence based majority did not centrally process evidence Social representations Semantic barriers used only by non-evidence based jurors Position maintenance

57. If evidence-based jurors Understand the evidence Problem solve evidence Do not use explanation-based reasoning. Then…………….

58. What is the jury leniency bias? 1. Genuine leniency bias : nullification 2. CSI effect : reliance on the infallibility of scientific evidence 3. Lay perceptions of the law : not the strict legal definitions 4. Or is it because the jurors do not understand the evidence?

59. Then jury leniency bias is The leniency bias can occur because juries do not understand the evidence Evidence based jurors did not show a CSI effect Evidence based jurors did not redefine reasonable doubt The CSI effect & redefinition of legal terms were both a result of not understanding evidence