Criminological psychology (option) contemporary study: Ruva, McEvoy and Bryant (2007)

Aim and sample

Aim: to investigate the effects of pre-trial publicity (PTP) and jury deliberation on jurors' verdicts and memory.

Sample: 558 university students (128 male, 430 female), aged 18 to 52 (mean 20.6), given course credit; ethnically diverse; 6 had served on a real criminal jury.

Procedure

Phase 1: in groups of up to 16, participants read news articles. Exposed groups read real (modified) PTP about the defendant, including information not given at trial that could bias them. Non-exposed groups read articles about an unrelated crime. Packets were matched (9 articles, 10 pages).

Phase 2 (about 4 days later): all watched an edited 30-minute videotape of a real murder trial (a man accused of shooting his wife; he claimed she shot herself accidentally). Each juror gave a verdict (not guilty, hung, guilty), a confidence rating and a sentence (30 to 45 years).

• Nominal juries (5 to 6 people) did not discuss; each recalled facts alone.
• Deliberating juries (4 to 6 people) discussed for 30 minutes to reach a unanimous verdict.
• A source monitoring (SM) test asked whether each statement had appeared in the trial or in the articles.

Results

Selected means from Table 1, Pearson WPS03 summary of studies

Findings, conclusions and evaluation

• Exposed jurors gave more guilty verdicts and longer sentences and rated the defendant as less credible.
• Exposed jurors more often misattributed PTP-only information to the trial (source memory errors).
• After deliberation, guilty verdicts fell in the deliberating groups (a leniency shift), but deliberation increased bias in credibility ratings. Deliberating jurors were more confident in both correct and incorrect source judgements.
• Conclusion: negative PTP strongly biases jurors, and they may be unable to disregard it even when told to; deliberation does not reliably remove the bias.

Evaluation: random allocation and a control (non-exposed) group allow cause and effect; a real trial video and real PTP increase realism; large sample. But students knew their verdict had no consequences, the trial was shortened to 30 minutes, and PTP was read in a lab rather than met naturally over weeks (lower ecological validity); the sample was mostly female students (generalisability). Deception about the true aim was minor and participants were debriefed.

Worked example

Using the pre-deliberation means for deliberating juries, how much longer was the mean sentence for exposed jurors?

1. Exposed: 40.71 years. Non-exposed: 37.74 years.
2. 40.71 - 37.74 = 2.97 years longer.
3. This supports the idea that negative PTP makes jurors harsher.

Answer: 2.97 years longer.

Check yourself

1. What were the two independent variables in Ruva et al. (2007)?
   • Attractiveness and race of the defendant
   • Weapon presence and stress
   • Verb used and time delay
   • Exposure to pre-trial publicity and whether jurors deliberated
   Show answer

   Exposure to pre-trial publicity and whether jurors deliberated. PTP exposure and deliberation.

2. Ruva et al. had 558 participants, 430 of them female. What percentage were female? Give your answer to 1 decimal place.
   Show answer

   77.1 %. 430 / 558 x 100 = 77.1%.

3. What is a source memory error in this study?
   • Forgetting the defendant's name
   • Giving a not guilty verdict
   • Refusing to deliberate
   • Believing information from the news articles was presented at the trial
   Show answer

   Believing information from the news articles was presented at the trial. Misattributing the source of information.

4. Pre-deliberation confidence for deliberating jurors was 5.29 (exposed) and 4.08 (non-exposed). What is the difference? Give your answer to 2 decimal places.
   Show answer

   1.21. 5.29 - 4.08 = 1.21.

5. What effect did deliberation have on guilty verdicts?
   • Guilty verdicts rose sharply
   • Deliberation had no effect on any measure
   • Guilty verdicts fell after deliberation (a leniency shift)
   • All deliberating juries were hung
   Show answer

   Guilty verdicts fell after deliberation (a leniency shift). A leniency shift, though credibility bias increased.

6. Which is a weakness of Ruva et al. (2007)?
   • Mock jurors knew their verdict had no real consequences
   • There was no control group
   • Participants were not randomly allocated
   • The trial was fictional and invented by the researchers
   Show answer

   Mock jurors knew their verdict had no real consequences. Low ecological validity of mock juries.

7. Explain one practical application of Ruva et al.'s (2007) findings.
   Show answer

   Because negative pre-trial publicity biases jurors even when they are told to ignore it, courts could delay trials, move them to another area, or restrict media reporting before a trial.. A real-world change and why.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Psychology specification, Issue 6 (November 2024, first assessment January 2026)
• Pearson IAL Psychology summary of studies: WPS03

Last updated 8 November 2026. Spotted a mistake? Tell us.