How does anxiety affect EWT

The Weapon-Focus or 'Tunnel' Effect

This is where in violent crimes the witness will focus on central details of the attack (e.g. the weapon) rather than peripheral details (e.g. what the perpetrator looked like).

Attention narrows and we have tunnel vision on the weapon because it makes us anxious.

Johnson & Scott (1976)

Procedure:

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

• Low anxiety: Heard a casual conversation and saw a man carrying a pen.

• High anxiety: Heard an argument and breaking glass, then saw a man carrying a blood-covered knife.

Findings:

• Pen condition: 49% correctly identified the man.

• Knife condition: 33% correctly identified the man.

Conclusion: Anxiety may reduce EWT accuracy due to weapon focus.

Yuille & Cutshall (1986)

Procedure:

• Studied 13 witnesses to a real shooting in Canada.

• Interviewed them 4–5 months later and compared their accounts with police records.

Findings:

• Witnesses showed high accuracy even after several months.

• High-stress witnesses were 88% accurate compared with 75% for low-stress witnesses.

Conclusion: Anxiety may improve EWT accuracy in real-life situations.

Further Support for Negative Effects

Valentine & Mesout (2009)

• Studied visitors to the London Dungeon's horror labyrinth.

• Used heart rate to measure anxiety.

• High-anxiety participants were less accurate when identifying an actor.

Conclusion: Anxiety can reduce EWT accuracy.

Further Support for Positive Effects

Christianson & Hubinette (1993)

• Interviewed 58 witnesses to real bank robberies in Sweden.

• Direct victims recalled more accurately than bystanders, despite experiencing greater anxiety.

Conclusion: Anxiety may improve EWT accuracy.

Limitation: Interviews occurred months later, so other factors, such as post-event discussion, may have affected recall.