Yuille and Cutshall

Aim

Investigate whether leading questions affect eyewitness memory in a real-life crime scene and examine the accuracy and reliability of eyewitness testimony over time

Procedure

Real-life crime scene: Vancouver, Canada

A thief robbed a gun shop, tied up the owner and then shot him

Police arrived and then killed the thief

21 eyewitnesses were interviewed by the police

Four months later, researchers re-interviewed 13 eyewitnesses

Method

Witnesses gave their own account of the crime

They were then asked two leading questions

Witnesses rated their stress level on seven-point scale

Findings

Eyewitness testimony was highly accurate

--> details were consistent with police reports

Leading questions had little to no effect on memory recall

High-stress witnesses had the most accurate recall

Memory remained reliable even after four months

Conclusion

Challenges the reconstructive memory theory

Suggests that memory reliability may depend on the nature of the event and emotional involvement

Evaluate

(+) High ecological validity - real-life crime scene

(-) Low reliability - study can't be replicated as it was a one-off incident

(-) Low internal validity - low control over extraneous variables

--> different witnesses may have had varying levels of rehearsal

--> no way to measure what they had discussed or thought about in the four months between the crime and the study