Studies into factors affecting eyewitness testimonies

Lotus (75)

• Showed Ps a video of a car driving

• Asked Ps in condition 1 ‘how fast was the car driving?’

• Asked Ps in condition 2 ‘how fast was the car driving when it passed the barn?’ (There was no barn)

• A week later they asked them if they saw a barn in the video

• Condition 1 - 2.7%

• Condition 2 - 17.3%

Loftus and Palmer

• showed Ps a car crash video

• Asked them ‘how fast were the cars going when they _____?’

• They replaced the verb each time

• Later, asked Ps to estimate how fast the cars were travelling

• They found as the verb changed, the speed they estimated changed

Loftus and Zanni

• showed Ps a video of a car crash

• Either asked them, ‘did you see a broken headlight?’ vs ‘did you see the broken headlight?’ (NO HEADLIGHT)

• When they used ‘a’ 7% said yes

• When they said ‘the’ 17% said yes

Krakow and Lynn

• 4-5 year old children played twister with an experimenter called Amy

• During the game, Amy either touched them on the arm, leg, torso etc. or didn’t touch them at all

• Later the children were either asked a leading question (‘Amy touched your bottom, didn’t she?’) or a non-leading question (‘Did Amy touch your bottom?’)

• When they asked the leading question, over 50% of the kids said yes even if they weren’t touched at all

Anna Lindh Swedish foreign minister

• murdered

• Real witnesses has to report to police any possible description of the murderer

• They were allowed to discuss what they thought with each other

• One witness thought the murderer was wearing a camouflage jacket and told the other participants

• The camouflage jacket became a large aspect of the search

• In the end, the murderer was actually wearing a grey jacket

Gabbert et al

• Ps put in pairs

• Shown the same video but either video had a unique item in it

• They were then allowed to discuss the video believing they’d watched the same one

• 71% reported seeing the unique item that wasn’t in their version of the video

Baron et al

• found Ps EWTs were more accurate when they believed it would be used for an important purpose (police, court)

Pickel

• Ps sat in a hair salon and a person entered carrying one of four things

• 1 - wallet (low surprise, low threat)

• 2 - a raw chicken (high surprise, low threat)

• 3 - a pair of scissors (low surprise, high threat)

• 4 - a gun (high surprise, high threat)

• Ps were more likely to be able to accurately recall the high surprise items than low surprise

• Indicated surprise may matter more than threat levels

Valentine et al

• London dungeons

• Scare actors scared them

• Hooked up to heart rate monitors and had to rate anxiety in a questionnaire afterwards

• Sorted into low anxiety or high anxiety groups

• Had to identify the scare actors in a lineup

• More likely to be able to identify scare actor in the high anxiety group (75%)

Yerkes-Dodson Law

• too low or too high anxiety hinders accurate recall

• Moderate levels of anxiety helps accurate recall