Factors affecting the accuracy of EWT

What is anxiety

A state of emotional and physical arousal

It is a typical reaction to stressful situations => can effect the accuracy and detail of EWT

the feelings include:

• tension

• unease

• physical changes => sweating and increased HR

Who researched the effects of anxiety on EWT

Johnson and Scott 1976

What was Johnson and Scott’s procedure to measure the effects of anxiety on EWT

• Participants believed that they were taking part in a lab study

• while seated in a “waiting room”

• participants heard a conversation in the next room and saw a man leave and walk past holding a pen => this was the low-anxiety inducing condition

• the other participants overheard a heated argument in the next room, and the sound of breaking glass. They then witnessed a man emerge holding a knife with blood on it => this was the high-anxiety inducing condition

What were Johnson and Scott’s findings to their experiment which measured the effects of anxiety on EWT

• participants of the study were then asked to pick the man out from a set of 50 photos

• 49% who had seen the man carrying the pen were able to identify him

• Only 33% of participants who had seen the man with the knife were able to identify him => this suggests that the tunnel theory interfered with their memory of the man

What is tunnel theory

the tunnel theory of memory argues that people have enhanced memory of central events

• the weapon focus as a result of anxiety can have this effect

What are some limitations of Johnson and Scott’s study

• May not have tested the individuals anxiety as reason why EW focused

On weapon was because they were surprised to see it

• PICKEL 1988

• => CONDUCTED AN EXPERIMENT USING SCISSORS, A HANDGUN, A WALLET AND A RAW CHICKEN => MOST RECALLED ITEM WAS THE CHICKEN BECAUSE THEY WERE ITEMS OF HIGH UNUSUALNESS

• This suggests that the weapon focus effect is due to unusualness rather than anxiety

• It is measured in a way which acts as a extraneous variable

What can anxiety also do

anxiety can also increase alertness and this may improve memory for an event as we become more aware of cues in the situation

Who studied the benefits that anxiety can have on recall

Yuille and Cutshall 1986

• they conducted a study on an actual shooting in a gun shop in Vancouver Canada

What was Yuille and Cutshalls procedure of the study

• Owner shot the thief => there were 21 EW

• 13 EW’s took part in study

• Interviewed 4-5 months after the shooting

• Interviews were compared to the real ones with the police after the shooting

• Accuracy = measured by the no. of details reported on each account

• Witnesses also rated on scale 1-7 the stress of the situation they felt + whether they had any emotional reaction afterwards and since the event

What were Yuille and Cutshalls findings for their study

• Eyewitnesses = had very accurate in accounts + little changed in each account which was recalled

• Some witnesses increased their accuracy after 5 months

• Most stressed witnesses were the most accurate in their response at 88% accurate

• 75% accurate for less stressed group

=> This suggests that anxiety does not have a detrimental impact on the accuracy of eyewitness memory in a real world context + may enhance it 

What are some strengths of Yuille and Cutshall’s research into the benefits on anxiety on recall

Christianson and Hubinette 1993

• interviewed 58 witnesses to actual bank robberies in Sweden

• some witnesses = directly involved (bank workers)

• Some witnesses = not directly involved (bystanders)

• researchers assumed that those who wee directly involved were more likely to have an accurate recall of the event

• They found that 75% or the witnesses were accurate in their recall

• the most anxious people (directly involved) = were the most accurate

• this finding shows that actual crimes confirm that anxiety does not reduce the accuracy of recall of EW’s and can even enhance it