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Asymmetries in Prior Conviction Bias (Presentation Slides, Accompanying Notes to Cowley & Colyer, 2010)

Article in SSRN Electronic Journal · January 2019

DOI: 10.2139/ssrn.3353138

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Asymmetries in prior conviction bias

• Dr. Michelle Cowley

Centre for Socio-Legal Studies University of Oxford Juliette B. Colyer School of Psychology University of Plymouth

Overview

 Illustrative example: child abuse cases  The legal context  Psychological studies on prior conviction bias  A new theory of mental representation  Predictions and quantitative experiment design  Pilot study: Underlying ratings of guilt  Study 1: Prior convictions and forensic evidence  Study 2: Prior convictions and community disclosure

*New Summary Presentation Slides (2019) to: Cowley, M., & Colyer , J. B. (2010). Asymmetries in prior conviction reasoning: Truth suppression effects in child protection contexts, Psychology, Crime and Law, 16(3), 211-231.

Megan’s Law

• Megan Kanka was killed by a sex offender who unknown to

her community lived in her neighbourhood.

• Within months, New Jersey passed emergency legislation for

a compulsory notification for sex offenders with previous

• convictions. All states in the US passed this legislation.
• ‘Megan’s Law will protect tens of millions of families from

the dread of what they do not know’ (Bill Clinton, 2000, cited in Pawson, 2006).

Criminal Justice Act (2003)

• The Criminal Justice Act outlines law governing prior conviction disclosure (2003,

Ch.1, part 11, sections 98-113).

• Namely, that it is now admissible to disclose proof of a prior conviction.
• the law of criminal evidence should generally move towards trusting judicial and lay

fact finders when they assign weight to relevant evidence

• and move away from a clinical use of technical rules of admissibility[1][2].
• The criteria of interest in child abuse cases is where:
• (i) the evidence is evidence of a person’s misconduct, and
• (ii) it is suggested that the evidence has probative value by reason of

similarity between that misconduct and other alleged misconduct. [1] ‘Review of the Criminal Courts of England and Wales’ (HMSO, 2001) [2] The Law Commission report ‘Evidence of Bad Character in Criminal Proceedings’ (Law Commission, No 273, cm 5257, 2001)

Studies of prior conviction bias

Prior convictions in real cases

• Kalven & Zeisel (1966)- 27% more often
• Bottoms & Goodman (1994)- child witness corroboration

Limiting instructions and diffusion

• Greene & Dodge (1995)- credibility vs guilty
• Doob & Kirshenbaum (1973)- time for pc

Deliberation and alternative stories

• London & Nunez (2000)
• Pennington & Hastie (1986)

Similarity and dissimilarity of prior conviction

• Wissler & Saks (1985)- murder and autotheft

A new theoretical element: Mental Representation

• Inconsistent findings over 40 years
• Evaluating appropriate use re CJA (2003) is problematic
• Evidence based evaluation should be extensive
• Theoretical framework to explain inconsistencies
• Possibilities in mind (Johnson-Laird, 2006)
• Principle of truth
• Principle of consistency
• Explicit alternatives and counterexample search

Predictions

• We cannot assume consistent additive probative value for

prior conviction evidence- prompting a primary mental representation of guilt.

• Evidence that would be otherwise considered irrelevant, may

be attributed more relevance if it is consistent with a representation prompted by a prior conviction- lense of diffusion

• This representation may prompt auxiliary stereotypical

criminal representations including re-offending

• Explicit evidence of ‘no prior convictions’ will be more

difficult to process than explicit evidence of a prior conviction.

• Prior conviction evidence suppresses alternative possibilities

Pilot study

 Fifty one participants: 8 men and 43 women  Mean age 20.64years, range from 19 to 33 years  Design: 1 x 3 (control, one previous, two previous)  Materials: Reasoning about a scenario created from a real life case

• f a child who was killed by a man with two previous convictions

for similar offences.  On January 2, 2006, David Baxter had been arrested. He had been accused of killing 18-month-old Joanna Connolly. Joanna’s skull had been fractured when she received a physical blow to the head. She was the daughter of Susan Connolly, the woman who David Baxter had been seeing.

Pilot study

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…

Pilot study

Fig 1. Percentage of verdict type per condition. Regardless of the number of previous convictions people could not decide if the defendant was guilty.

Chi2= 75.444 (2), p <.0005

Pilot study

Fig 2. Underlying ratings of guilt were higher when a previous conviction was present than when a previous conviction was not present regardless of the number of previous convictions. Kruskal-Wallis chi2= 16.162 (2), p <.0005

Experiment 1

 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
• r

 Forensic evidence showed that the blow was delivered by a right-handed

• person. David Baxter is right-handed

Experiment 1

Fig 3. The number of people of a twelve person jury, who came to a ‘guilty’ ‘not guilty’ or ‘cannot decide’ verdict in the presence of evidence of handedness (RH or LH) and/or previous convictions (PC). …People tend to significantly choose ‘cannot decide’ more often except when a previous conviction is accompanied by evidence of a left handedness match (PC and LH).

Experiment 1

Fig 4. Underlying mean ratings of guilt on a scale of 0-10 were higher when a previous conviction was present than when a previous conviction was not present regardless of the number of previous convictions (Kruskal Wallis, chi2= 12.282 (5), p <.031).

Experiment 2

• Ps. 48 (15 men and 33 women). The mean age was 34yrs (range: 19- 86 yrs).

Members of the public.

• Design. 1 x 3 (3 envelopes randomly assigned: ‘…will be released’/ ‘…one similar pc

and will be released’/ ‘…no similar pc and will be released’)

• Materials.

A man who is a convicted paedophile has made positive progress in prison. He has completed a strict, structured rehabilitation program which focuses on the prevention of re-offending.

• Q1. Do you think this man will re-offend?

Q.3. Do you think it is important to be informed if this man was to be located in your community? Measures: Yes/ no/ cannot decide, Rate how strongly (scale 0- 10) ……………………………………………………………………………………..

Experiment 2: PC vs No PC

One similar PC:

• Before: Yes (19%), No (6%),

Cannot decide (75%, p <.005)

• After: Yes (81%), No (6%),

Cannot decide (13%, p <. 005)

• Before (M = 5.19) vs After (M =

6.81, p <.05) No similar PC

• Before: Yes (44%), No (6%),

Cannot decide (50%), p >. 05)

• After: Yes (38%), No (6%),

Cannot decide (56%), p <.05).

• Scale: M = 6.19 vs M =6.00 ns.

Re-offend

Experiment 2 continued…

One similar PC Before: Yes (56%), No (19%), Cannot decide (25%) p <.05 After: Yes (62%), No (19%), Cannot decide (19%) p <.05. Scale: Before (M = 6.63) vs After (M = 6.63). ns No similar PC Before: Yes (31%), No (31%), Cannot decide (38%), ns After: Yes (38%), No (31%), Cannot decide (31%), ns Scale: Before M = 4.56 vs After M = 5.56, ns

Reveal Identity Reveal Identity 56 19 25 62 19 19

20 40 60 80 100 Yes No Cannot decide

Before envelope After envelope

Experiment 2 continued…

One similar PC Before: Yes (38%), No (0%), Cannot decide (62%), p <. 05. After: Yes (81%), No (0%), Cannot decide (19%), p <.005. Scale: Before (M = 5.25) vs After (M = 7.31), p <.005. No similar PC Before: Yes (56%), No (6%), Cannot decide (38%), p <. 05. After: Yes (44%), No (6%), Cannot decide (38%), p >.05. Scale: Before (M = 6.63) vs After (M = 6.00), p >.05.

Pose danger Pose danger 38 62 81 19

20 40 60 80 100 Yes No Cannot decide

Before envelope After envelope

Future directions

• Content analysis on the reasons for choice have

shown that the number of alternatives considered are significantly less when a pc is present.

• Individual cognition vs social cognition anticipating

social expectancies…

• Refuting evidence and explicit alternatives
• Prior acquittals and victimisation…

Thank you

• Thank you to Laura Pennicott for research assistance on

studies 1 and 2.

• Thank you to the University of Southampton’s Small

Grant Scheme, for funding part of this work.

• Thank you to the Americans for Oxford Katzenbach

Fellowship, for funding part of this work.

References

• Cowley, M. (2017). Hypothesis Testing: How We Foresee Falsification in Competitive Games.

Saarbrucken, Germany: Lambert Academic Publishing

• Cowley, M. (2017). ‘The Innocent v The Fickle Few’: How Jurors Understand Random-Match-

Probabilities and Judges’ Directions when Reasoning about DNA and Refuting Evidence. Journal

• f Forensic Science & Criminal Investigation, 5(3): 2017
• Cowley, M., & Colyer, J. B. (2010). Asymmetries in prior conviction reasoning: Truth suppression

effects in child protection contexts, Psychology, Crime and Law, 16(3), 211-231.

• Cowley-Cunningham, Michelle B. and Colyer, Juliette, Asymmetries in Prior Conviction Bias

(Presentation Slides) (March 15, 2019). Corresponding slides to Cowley & Colyer (2010) which appeared as a full paper in Psychology, Crime & Law. . Available at SSRN: https://ssrn.com/abstract=3353138 or http://dx.doi.org/10.2139/ssrn.3353138

• Cowley, M. (2014). M-Level Quantitative Methods in Socio-Legal Studies: A Methodology Clinic

Workbook – CSLS, University of Oxford. Law Educator: Courses, Materials, & Teaching SSRN eJournal Catalogue.

• Cowley-Cunningham, M. (2019). Psychology of Law: 3 Critical Empirical Legal Problems. Law &

Society: Criminal Procedure eJournal, vol. 14, Issue 24: 24 April, 2019. Law & Society SSRN eJournal Series sponsored by the Maurer School of Law, Indiana University.

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