Factors Affecting EWT: Anxiety Flashcards
Anxiety:
A state of emotional and physical arousal. The emotions include having worried thoughts and feelings of tension. Physical changes include an increased heart rate and sweatiness. Anxiety is a normal reaction to stressful situations, but can affect the accuracy and detail of EWT.
Johnson and Scott (1976): Procedure
- Led pps to believe they were going to take part in a lab study. Whilst waiting in a waiting room pps heard an argument in the next room.
- Low anxiety condition a man walked through the waiting area, carrying a pen and with grease on his hands.
- Others heard the same argument, but accompanied by the sound of breaking glass. Man walked out of the room holding a paper knife covered in blood.
Johnson and Scott (1976): Findings
- The participants picked out the man from a set of 50 photo, 49% of the participants who had seen the man carrying the pen were able to identify him.
- The corresponding figure for the blood-covered knife was 33%.
- The tunnel theory of memory argues that a witness’s attention narrows to focus on a weapon, because it is a source of anxiety.
Yuille and Cutshall (1986): Procedures
- Conducted a study of real-life shooting in a gun shop in Vancouver, Canada. The shop owner shot a thief dead.
- There were 21 witnesses- 13 agreed to take part in the study.
- Interviews held 4-5 months later and these were compared with the original police interview. Accuracy was determined by the number of details in the account.
- They were also asked to rate how stressed they felt at the time of the incident, using a 7 point scale and asked if they had emotional problems since the event.
Yuille and Cutshall (1986): Findings
1.Witnesses were very accurate in their accounts and there was little change in the amount of accuracy after 5 months.
2. There were some details that were less accurate (colour of items and age/height/weight estimates).
3. Highest levels of stress 88% accurate vs 75% low stress group (reported).
Contradictory Findings: Yerkes and Dodson (1908)
- According to them, the relationship between emotional arousal and performance looks like an inverted U.
2.Kenneth Deffenbacher (1983) applied the Yerkes-Dodson Law to EWT. Lower levels of anxiety produce lower levels of recall accuracy. - Memory becomes more accurate as the level of anxiety experienced increases, there is a point of optimal anxiety reaches.
- This is the point of maximum accuracy, if any more stress is experienced, their recall of the event suffers a drastic decline.
Valentine and Mesout (2009): Procedure
- Carries out study in the real-life setting of the Horror Labyrinth at the London Dungeon.
- It is designed to be frightening with many ‘scares’ such as darkness, screams, gory models and sudden movements.
- Visitors agreed to complete questionnaires at the end of their visit to assess their level of self-reported anxiety.
- They wore wireless heart monitors to confirm that they were experiencing anxiety.
Valentine and Mesout (2009): Findings
- The pps task to describe a person encountered in the Labyrinth (an actor). High anxiety pps recalled the fewer correct details of the actor and made more mistakes.
- 17% of high anxiety group correctly identified the actor in the line-up to compared to 75% correct identification by those in the low anxiety group.
E: Weapon Focus Effect May Not Be Relevant
- May test surprise rather than anxiety. The reason participants focus on the weapon may be because they are surprised at what they see rather than because they are scared.
- Pickel (1998) conducted an experiment using scissors, a handgun, a wallet or a raw chicken as the hand-held items in a hairdressing salon video.
- EWT accuracy was significantly poorer in the high unusualness conditions.
- Weapon focus effect is due to unusualness rather than the anxiety/threat.
- Tells us nothign specific about the effects of anxiety on EWT.
E: Field Studies Can Lack Control
- Usually interview real-life eye-witnesses sometime after the event.
- All sorts of things could have happened to the pps that the researcher have no control over, discussion with co-witnesses, accounts they may have seen in the media, the effects of being interviewed by the police.
- This is a limitation of field research because it is possible that these extraneous variables may be responsible for the accuracy of recall.
- The effects of anxiety may be overwhelmed by these other factors, and impossible to assess by the time the participants are interviewed.
E: Ethical Issues
- Creating anxiety in participants is very risky. It is potentially unethical because it may subject people to psychological harm purely for the purposes of research.
- This is why real-life studies are beneficial- psychologists interview people who have already witnessed an event so there is no need to create it.
- This issue doesn’t challenge the findings from studies such as Johnson and Scott but it does question the need for such research.
E: The Inverted-U Explanation Is Too Simplistic
- Anxiety is very difficulty to define and measure accurately. One reason for this is that it has many elements- cognitive, behavioural, emotional and physical.
2.But the inverted U shape explanation assumes only one of these is linked to poor performance- physiological arousal.
E: Demand Characteristics
Most lab studies show participants a filmed and usually staged crime. Most of these participants will be aware they are watching a filmed crime for a reason to do with the study. Chances are most of them will work out for themselves that they are going to be asked questions about what they have seen.
