Psychology: Memory - Eyewitness testimony: Anxiety

Johnson and Scott (1976) ‘Anxiety has a negative effect’ procedure

• Pps sat in a waiting room believing they were going to take part in a lab study

• Low anxiety condition: pps heard a casual convo then saw a man walk through waiting room carrying a pen and grease on his hand

• High anxiety condition: pps heard a heated argument accompanied by the sound of breaking glass, then a man walked through the room holding a knife covered in blood

• Pps were later asked to pick from a set of 50 pics of men

Johnson and Scott (1976) ‘Anxiety has a negative effect’ findings

• 49% of pps in low anxiety and 33% of high anxiety condition correctly identified the man

• The tunnel theory of memory argues that people have enhanced memory for central events.

• Weapon focus as a result of anxiety can have this effect

Yuille and Cutshall (1986) ‘Anxiety has a positive effect’ procedure

• In an actual crime a gun-shop owner shot a thief dead, there were 21 witnesses, 13 agreed to be in the study

• Pps were interviewed 4-5 months after the incident

• Info recalled was compared to police interviews at the time

• Witnesses rated how stressed they felt at the time of the incident

Yuille and Cutshall (1986) ‘Anxiety has a positive effect’ Findings

• Witnesses were very accurate in what they recalled after 5 months, there was little change from the police reports

• Pps who reported highest levels of stress were most accurate (88% compared to 75% of less stressed group)

• Anxiety doesn’t appear to reduce the accuracy of EWT, may even enhance it

Yerkes-Dodson (inverted U) theory

A little bit of stress can help you remember things better, but too little or too much stress makes memory worse. The best recall happens when stress is at the right level.

Inverted-U theory explaining different results in EWT studies

Some people remembered things badly because they were too stressed or not stressed enough. The theory explains that only a medium level of stress helps people remember well.

Limitation - anxiety may not be relevant to weapon focus

• Johnson and Scott’s pps might’ve focused on the weapon not because they were anxious but because they were surprised

• Pickel found accuracy in identifying the criminal was poorest when the object was unexpected e.g. they did the experiment with raw chicken

• Suggests weapons effect is due to unusualness rather than anxiety so tells us nothing about the effect of anxiety

Strength - supporting evidence for negative effects

• Valentine and Mesout used heart rate to divide visitors to London Dungeon’s into low and high anxiety groups

• High anxiety participants were less accurate than low anxiety in describing and identifying a target person

• Supports claim that anxiety has a negative effect on immediate EWT

Strength - supporting evidence for positive effects

• Psychologists interviewed actual witnesses to bank robberies - some were direct victims and others bystanders

• They found more than 75% accurate recall across all witnesses, Direct victims were even more accurate

• Suggests anxiety does not affect the accuracy of EWT and may even enhance it