Persuading a Jury.

Studies for C1 reaching a verdict, OCR psychology, forensic psychology. 

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Persuading a Jury; Pennington & Hastie.

Story order - evidence is arranged in natural chronological order. Witness order - closest order to original trial most shocking evidence at beginning and end. Primacy effect - first evidence heard is best remembered. Recency effect - last evidence heard is best remembered. 

Aim; To investigate whether or not story evidence is the  true cause final verdict decisions and the extent to which story order effects confidence decisions. 

Method; Lab exp. 130 students X4 conditions roughly equal numbers in each condition.condition 1  - 39 prosecution items in story order & 39 defence items in story order, condition 2  - 39 prosecution items in witness order & 39 defence items in witness order, condition 3  - 39 prosecution items in story order & 39 defence items in witness order, condition 4  - 39 prosectution items in witness order & 39 defence items in story order.  Procedure; Listened to tape recordings of stimulus trial responded to 2 written questions then asked to reach a verdict for murder then rate their confidence on a 5 point scale. 

Results & Conclusion; If defence presented witness order more found guilty if reversed defence had the benefits. Theory is supported, story order does matter when presenting evidence etc. 

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Persuading a Jury; Pennington & Hastie.

Evaluation; Ecological validity may be reduced - this is because it was done in a lab which is not a natural environment therefore it does not relate to everyday life overall reducing the overall validity. 

HOWEVER - this does mean there is high control over the situtaion which will in return increase the reliability of the study as it will be easy to replicate to gain the same results again. 

The sample was of a small size and only consisted of university students. Real life jury's consist of a mixture of people. This means that the results are only represensative of university students and can therefore not be generalised to everyone as a population. 

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Eyewitness testimony; Cutler et al.

Expert witness - someone who is a professor/doctor in a certain field and who can testify. likely to be biased but listened to more as they are trusted experts. 

Aim; Investigate whether hearing about psychological research from an expert witness which casts doubt on the accuracy of eye witness testimony would affect a jurors decision making by making them sceptical. 

Method and Procedure; lab exp. 538 students. 4 I.Vs. 1) withness identifying conditions (WIC). poor/good. 2) witness confidence. 80%/100% sure of identifying robber. 3) form of testimony. describing results/quantified. 4) Expert opinion. In half trials E.W expressed opinion on a scale of 0-25 which coincided with the poor and good conditions.

Results; JUROR VERDICTS - when WIC were good more guilty verdict. JURORS MEMORY - P's 85% correctly recalled testimony, memory cannot blamed lack effect on jurors judgement. memory from expert good 50% recalled 4 stages. JURORS CONFIDENCE - under good WIC jurors more confidence in accuracy of identification higher if EW/witness 100% confident. Conclusion; Showed expert testimony improved jurros knowledge making them pay more attention to WIC. Lower reliance on witness confidence. 

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Eyewitness testimony; Cutler et al.

Evaluation; Lab exp - gets rid of extraneous variables increasing the validity. HOWEVER ITIS REDUCTIONIST - behaviour is simplified - ignoring other evidential factors and 'missing the point'. 

sample - cannot be generalised results to anyone but students, as they may all have a similar thought process so may all act the same way, instead of differently like on a real life jury (also links to ecological validity). 

students were also given extra credits as it was part of their course therefore they may not even be interested in the case and may suffer from boredom effects. additionally with extra credits they may just rush the decisions for extra credits. 

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Inadmissible Evidence; Pickel.

Disregarding not allowed evidence. In order for evidence to be admissible in court its relevance must outweigh its potential prejudice. REACTANCE THEORY -doing something when told not to - eg dont look then looking. 

Aims; 1) look at effect of prior convictions 2) look role of judges instructions when followed by a legal explanation 3) examine how much credibility of a witness affects the jurors ability to ignore inadmissible statements 4) credibility of withness affects ability to ignore. 

Method; Mock trial using 236 uni students. Independent measures as viewed one of two conditions. questionnaires on decisions; 1 - verdict 2 - probable guilt of defendent 3 - 10 point scale rating of extent prior knowledge caused to believe guilty verdict 4 - credibility rating of witness. 

Procedure; X2 conditions. 1 - when admissible evidence was given by accident urors told to ignore it with a legal explanation. 2 - when admissible evidence was given by accident told to ignore it and no explanation. 

Results; admissible evidence told to ignore with no explanation followed instructions, those given explanation didnt. aims 1/3/4 NOT SIGNIFICANT. Conclusions; by calling attention to inadmissible evidence makes it more important to jury and they listen to it. 

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Inadmissible Evidence; Pickel.

Evaluation; Generalisabilty - although it is based on a USA procedure the findings are useful in a British conetxt. the study highlights the danger in assuming that legal explanations to juries are always beneficial. this means limited generalisabilty because the evidence was less complex than in a real trial, jurors were all students and presented an audio tape rather than video tape. 

Social Desirability bias - if the p's know they shouldnt be influenced by prior convictions but if they do may say they werent, 

Ecological validity - real jurors may have followed the judges' instructions more conscientiously knowing that the defendants future was in their hands; so as it was a mock trial the jury may not have thought as in-depth as a realy jury would. 

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