eye witness testimony Flashcards
what are the two types of misleading information in EWT
leading questions and post event dicussion
what is misleading questions
information included which may prompt or encourage witness
can lead to inaccuracy
what is the research for misleading questions
Loftus and Palmer
- students had to evaluate speed a car was going
- the verb that was used in the sentence was changed ranging from smashed to bumped
- found that more violent the verbs the higher the pps rated the speed they thought the car was going
- shoes EWT can be influenced by how the question is worded
what is post even discussion
discussion witnesses engage in after a crime with other witnesses
could result in contamination of original recall of events
what is the research investigating post event discussion
Gabbert
- pps were paired up
- each watched a crime from a different perspective with different aspects that were visible
- 71% recalled apects they would have been able to see which they got from the discussion
- 0% of control group did this
- shows how PED can contaminate EWT
how does anxiety have a positive effect on EWT
fight or flight - increase adrenaline causing pupils to dilate letting in more lights so can see better
research for positive effects of anxiety
Yuilie and Cutshall - canadian shooting
- their stole guns and money
- 13 witnesses interviewed at time and 5 months later. they were asked about their stress levels and 2 misleading questions
- more stressed = more accurate
- high anxiety can improve accuracy
how does anxiety have a negative effect of anxiety on EWT
weapon focused effect - witness is focused on the central detail (weapon) and ignores peripheral details (criminal)
research into negative effects of anxiety on EWT
Johnson and Scott
- pps thought they were taking part in a lab experiment and were eating outside in waiting room
- low anxiety condition = pen and grease on hands
- high anxiety condition = pen knife and blood on hands (also a glass smash was heard)
- pps were not able to pick out criminal as well in knife condition due to the tunnel effect
strengths of misleading info on EWT
1) practical application by Loftus. people could be convicted of a crime baed on wrongful asked questions during interview
2) Clifasefi research. pps received false info that they had become ill after drinking certain alcohol. then reported strong diminished preference. fake info implanted a false memory
weaknesses of misleading info on EWT
1) studies usually conducted in a lab. not real strong emotions as watched videos. effect of misleading questions might not actually be measured but anxiety instead (lack internal validity)
2) Loftus used student sample. although maybe more intelligent likely of not been able to drive - hard to interpret speeds
strengths of anxiety
1) practical application - shown how different EWT can be dependant if there was a weapon or not. police need to be aware to minimise the impact by using cognitive interview
2) Yuilie study was natural. event and anxiety was real. natural behaviour ecological validity high
weakness of anxiety
1) extraneous variable (shooting study) interviewed five months after crime. post event discussion. lacks internal validity
2) validity of weapon focus effect. assumed pps looked at it due to fear. pickle redid experiment in hair dressers using raw chicken sicissors and gun. found that recall was affected by the unusual object (chicken) not most scary. internal validity problems
