Factors Affecting eye witness testimony

Factors

• Misleading information in Leading questions

• Misleading information in Post event Discussion

• Anxiety

Leading questions

A question which, because of the way it’s phrased, suggests a certain answer

Leading questions contain misleading pieces of information or wording are usually closed

Research into leading questions, Loftus and Palmer (1974)

Procedure:

• 45 students shown 7 films of traffic accidents

• students were given a questionnaire

• there was one critical question about how fast the cars were going- each with a different verb

Findings:

• Contacted (32mph)

• Hit (34mph)

• Bumped (38mph)

• Collided (39mph)

• Smashed (41mph)

Conclusion:

Shows that misleading or suggestive information can distort eye witness

Follow up study: Loftus and Zanni (1975)

Shown clips of car accidents and asked ‘did you see the broken headlight’ others asked ‘did you see a broken headlight’, 17% said they saw it with the definitive, 4% said they saw it without the definitive

Evaluation points for Leading Questions

Research -

Practical application +

Validity +

Validity -

Post event discussion

When witnesses to a crime discuss the events with each other their memories can become contaminated, this could be because of a number of factors, but police get concerned about the quality of their evidence

Retroactive interference + source confusion

• If a witness hears new information about the crime may confuse their old memories of the event with new details they may not have witnessed

• People may hear extra details from media courage or in conversations with other witnesses or people they knew they didn’t see themselves but either consciously or unconsciously add it to witness memory

Memory conformity

• Normative social influence- witnesses may discuss with other witnesses or people what they saw, they may conform and say the same details as another just to be liked, even if they didn’t see it themselves

• Informational social influence- witnesses want to give the best accounts they can in post event discussion, they may learn details about the crime, that they did not witness themselves but then conform and report them in their testimony and because they want to be right in their account to the police

Repeat interviewing + reconstructive nature of memory

• Witnesses to a crime are often interviewed multiple times, after their initial interview, witnesses may have gone away and had conversations with other witnesses, or people they know as well as see some of the media towards the event

• Follow up interviews can lead to recalling details they didn’t actually see themselves (occurs when there’s a large gap between interviews

• Witnesses may forget details of their accounts in between interviews

Research: Gabbert et al (2003)

• Investigated the effect of post event discussion on the accuracy of eyewitness testimony, her sample consisted of 60 students from the University of Aberdeen and 60 older adults recruited from a local community

• Participants watched a video of a girl stealing money from a wallet. The participants were either tested individually (control group) or in pairs (co-witness group). The participants in the co-witness group were told that they had watched the same video however they had in fact seen different perspectives of the same crime and only one witness had seen the girl steal

• They discussed the crime together and all of the participants completed a questionnaire testing their memory of the event

• Gabbert et al found 71% of the witnesses in the co witnesses in the co witness group, recalled information they had not actually seen and 60% said that the girl was guilty despite not seeing her commit the crime

• This highlights the issue of post event discussion and the powerful effect this can have on the accuracy of eyewitness testimony

Evaluation points of Post event discussion

Research support +

Other factors -

Validity -

Practical applications +

3 areas of anxiety affecting eyewitness testimonies

1. The anxiety of the eyewitness

2. The weapon focus effect

3. Increased violence

Anxiety (arousal) of the witness

• Witnesses may be in a state of high arousal, this will be particularly likely if there is threat/danger

• some witnesses may have a naturally more anxious personality

• Something known as the ‘Yerkes-Dodson law’ predicts how anxiety affects our performance

Yerkes-Dodson model

The Yerkes-Dodson model of performance suggests that memory operates best at a moderate level of anxiety, but high anxiety leads to lower levels of recall

Unfortunately, most victims will experience too high levels of anxiety during the criminal act

Research: Defenbacher et al (2004)

• carried out a meta-analysis of 63 studies into the effects of anxiety on eyewitness memory

• Found that high levels of anxiety had a negative impact, not only on the accuracy of crime related details but also on the accuracy of identifying the perpetrator

• The above findings offer compelling support to the idea that anxiety makes EWT less accurate

Weapons focus affect

if a witness views a threat they are more likely to pay attention to the threat (weapon) then the event

Weapon research: Johnson and Scott (1976)

Aim: to find out whether anxiety in eyewitness testimony affected later identification

Procedure: Participants overheard an argument (in adjoining room) whilst sitting in a waiting room, they were exposed to 1 of 2 conditions

1. man ran through the room holding a pen with grease covered hands

2. man runs through holding a knife covered in blood

Findings: 49% correctly identified man in condition 1, 33% identified man in condition 2

Conclusion: supports that weapon focus effect happens as the participants focused more on the weapon then the person

Evaluation points

Internal validity +

Reliability +

Internal validity -

Inconsistent research -