psychology and the courtroom - crime


Characteristics of witnesses:

  • Witness confidence = more confident witness is a more accurate witness.
    • Penrod and Cutler - mock trial experiment for a robbery. When witness was 80% confident there was 60% conviction. When 100% confident there was 67% conviction.
  • Language use - Lakoff studied the effect of frequent hedges (I think, maybe). Both male and female witnesses who used these were perceieved as less intelligent + less believable

Characteristics of suspects:

  • Attractiveness Dion et al  coined the "halo effect", "what is beautiful is good". 
    • Sigall and Ostrove - lab, 120 students, IV = type of crime/attractiveness, DV = sentence. Burglary or fraud. Lower for buglary (2.8) for attractive, higher for fraud (5.45) 
    • Castellow et al - 71m 74f East Carolina uni, lab exp, rate guiltiness of sexual harrass with unattractive/attractive victim and suspect. Combination of attractive V and unattractive D = higher % of guilt. Assumed attractive victim = more innocent.
  • Accent = certain accents perceived more positive than others.
    • Seggie - tape recordings Australian, British RP and Asian. Aus = assault. Brit = fraud. 
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Key Research: Dixon et al

Aim: investigate impact of accent, race and type of crime on guilt

Hypothesis: Brummie suspect would be more guilty than standard accent.

Sample: 119 undergraduate students from University of Worcester (24m 95f) Those from Birmingham were removed from study.

Research Method: lab exp, independent measures, 3 IVs = accent (Brummie/Standard, race (black/white), type of crime (robbery/fraud). DV = participant's attributions of guilt.

Procedure: 2 minute recorded transcript between middle-aged male officer and young male suspect pleaing innocence. IVs were all varied within the transcript creating 8 different versions. Once listened to recording, they completed 2 rating scales: level of guilt on 7-point rating scale and speech evaluation instrument measuring superiority, attractiveness and dynamism. 

Results: Brummie suspect more guilty. Higher ratings for Brummie/black/burglary. Brummie rated low on superiority.

Conclusions: a range of social psychological factors can influence perceptions of guilt, accent, race and type of crime.

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Strategies to influence jury decision making

  • Attractiveness - could influence jurors, lawyers do get their clients to present themsevles in the most positive way - evidence from Sigall and Ostrove and Castellow et al.
  • Order of testimony - story order (order of events) or witness order (presented in sequence more likely to persuade jury e.g. best until last).
    • Pennington and Hastie - story order vs witness order. 130 students from USA in mock murder trial. Tape recordings presented in 4 different conditions.
      • Prosecution = SO, defence = WO
      • Prosecution = SO, defence = SO
      • Prosecution = WO, defence = SO
      • Prosecution = WO, defence = WO
    • ppts taken individually to answer written Qs, guilty or not guilty and rate confidence on 5 point rating scale. 
    • Results showed that prosecution using SO and defence using WO guilty verdicts returned 78% of the time (P won). Defence using SO and prosecution using WO guilty verdicts returned 31% of the time (D won). When both used the same strategy, guilty verdicts were around 60%.
    • Therefore, the use of story order could be a strategy to persude juries. It is easier for them to understand + make sense of evidence. But no advantage if both sides use it
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Socially sensitive: causes implications for the ppts and who the findings generalise to

  • Seggie - British RP guilty of fraud, broad Aus guilty of assault. This is ** as it assumes those with broad Aus more likely to commit blue-collar crimes, and British = white-collar 
  • Dixon et al - Brummie accent more likely to be seen as guilty of committing crimes. ** leads to labelling and being discriminated against due to their accent, people treat them differently e.g. not serving them in pubs etc. 
    • Could be +ve inform legal teams about guilt can be influenced by extra-legal factors. Also, raise awareness in schools about prejudice. Could use voice-changing softwarre so jurors don't actually hear the accent.

Ethnocentrism: all the research is from UK, US or Australia. Ethnocentric to assume that a jury's decisions in different countries and cultures may be affected by the same factors. May only affect jurors in western countries. Need to investigate jury decisions in a range of countries/cultures. 

Validity: ecological validity extent to which study reflects real life. Low EV because Castellow's research is a mock trial, only shown photos. Not reflective of a real trial. But allows comparisons among different conditions which couldn't be manipulated in real life.

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