EWT: Anxiety

• 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 . This is a normal reaction to stressful situations but can effect the accuracy of EWT.
• Tunnel theory

  Argues that a witness's attention narrows to focus on a weapon, because its a source of anxiety
• Fight or flight response

  An emotional and physiological reaction to an emergency that increases readiness for action- this improves memory because it increases our alertness and we become more aware of cues
• Weapon focus effect

  When the anxiety of seeing this focuses all your attention and you can't see much else
• Yerkes-Dodson (1908) Law (inverted u)

  Lower levels of anxiety produce lower levels of recall accuracy. But memory becomes more accurate as the levels of anxiety increase. However there is a point where the optimal level of anxiety is reached. This is the point of maximum anxiety. If an eyewitness experiences any more anxiety than this, than their recall of the event declines. It is curvilinear.
• Deffenbacher (1983) - effects memory

  Found lower levels of anxiety did produce lower levels of recall accuracy. Recall accuracy increases with anxiety up until an optimal point. A drastic decline in accuracy is seen when an eyewitness experiences more anxiety than the optimal point.
• Explain Christianson & Hubinette's (1993) research into anxiety

  Questioned real victims of a bank robbery. They found that those who had actually been threatened were more accurate in their recall, compared to those who were onlookers. This continued to be true 15 months later.
• Johnson and Scott (1976) procedure


  Led participants to believe they were taking part in a lab study and told to wait in the waiting room.

  -P's heard an argument in the next room

  in the low anxiety condition, a man walked through the waiting area, carrying a pen and his hand was covered in grease

  -in the high anxiety group - the other participants heard the same argument, but this time heard glass smashing and the man walked out of the room with a paper knife covered in blood
• Johnson and Scott (1976) findings

  33% of participants in the high anxiety condition identified the person compared to 49% in the low anxiety condition. Few people noticed the pen whereas most participants noticed the letter opener, suggesting that focus on the weapon may prevent people from noticing important aspects of crime scenes.
• Yuille and Cutshall (1986)


  13 witnesses to a real life shooting which involved the owner of a gun store in Canada and an armed thief in which the store owner was wounded and the thief was shot dead were interviewed. Witnesses were at different distances from the shooting when it took place.
• Yuille and Cutshall (1986)


  Of the 21 witnesses 13 agreed to be participants. The accuracy remained similar and high for most of the witnesses even after 4 - 5 months and errors were relatively rare. Witnesses rated how stressed they felt at the time of the incident. Witnesses were very accurate and there was little change after 5 months. Ppts who reported highest levels of stress were most accurate 88% compared to 75% for less-stressed group. Stress did not affect memory negatively. Researchers found that witnesses experienced adrenalin more than stress. The stress came later.
• Deffenbacker 1983 found that lower levels of anxiety did produce lower levels of recall accuracy. Recall accuracy increases with anxiety up to an optimal point. A drastic decline in accuracy is seen when an eyewitness experiences more anxiety than is the optimal
• A limitation of the Johnson and Scott study is that it may test surprise not anxiety


  Participants may focus on a weapon because they are surprised at what they see rather than because they are scared. Pickel (1998) used scissors, handgun, wallet and raw chicken as hand-held items in a hairdressing salon. EWT accuracy was poorer for high unusualness (chicken and handgun) . So the weapon focus effect is due to unusualness rather than anxiety/threat and therefore tells us nothing about the effects of anxiety on EWT
• A limitation of field studies is that they lack control of variables

  Real-life witnesses are interviewed sometime after the event. Many things happen to them in the meantime that researchers cannot control. Example: eyewitnesses discuss the event with others; they read or view accounts in the media; the police interview may influence their memory (post-event discussions) These extraneous variables may be responsible for the (in)accuracy of recall not anxiety. It is difficult to isolate these variables.
• Another limitation is that there are ethical issues in this research area

  Creating anxiety in participants is potentially unethical because it may subject people to psychological harm purely for research purposes. So real-life studies are beneficial: psychologists interview people who have already witnessed an event, so there is no need to create it. Ethical issues don't challenge the findings of studies (e.g Johnson and Scott) but they do raise questions about conducting such research.
• The inverted-U explanation is limited because it is too simplistic

  Anxiety is difficult to define and measure because it has many elements - cognitive, behavioural, emotional and physical. The inverted-U explanation assumes that one of these is linked to poor performance - physiological arousal. The explanation fails to account for other factors; for example, the effects of the emotional experience of witnessing a crime on the accuracy of memory
• A limitation is that demand characteristics may affect lab studies of anxiety

  Most participants in controlled lab studies are aware they are watching a filmed (and staged) crime for a reason to do with a study. They may work out that they will be asked about what they have seen. They may give responses which they believe to be helpful to the researcher. So the researcher is not measuring the accuracy of EWT and this reduces the validity of research investigating the effects of anxiety.