factors affecting accuracy of EWT - anxiety

• what is anxiety?

  state of emotional and physical arousal such as tension and increased heart rate and its normal in stressful situations but affects accuracy of EWT as it creates physiological arousal preventing us from paying attention to cues so recall can be worse
• research supporting the idea that anxiety has a negative effect on recall (weapons)

  procedure: (johnson and scott) p's believed they are taking part in a lab study, p's in the low anxiety condition heard a casual conversation and a man carried a pen with grease, in the high anxiety a man held a bloody knife

  findings: p's later picked out the man from 50 photos, 49% in low anxiety group identified him and 33% in high anxiety identified him. the tunnel theory of memory argues that ppl have enhanced memory for central events, weapon focus as a result of anxiety can have this effect
• research that supports the idea that anxiety has a positive effect on recall (fight or flight increases alertness and therefore aware of cues)

  procedure: (yuille and cutshall) actual shooting in a gun shop in canada, shop owner shot the thief dead. 21 witnesses - 13 took part in study and interviewed 4-5 months later and it was compared with the original police interviews at the time of the shooting and accuracy was determined by the number of details recalled. the witnesses rated their stress levels in the time of the incident (7-point scale) and any emotional problems from it
• research that supports the idea that anxiety has a positive effect on recall (fight or flight increases alertness and therefore aware of cues)(2)

  findings: witnesses were accurate and there was little change in the amount recalled or accuracy after 5 months some inaccuracy such as colour of items and age and height estimates. those p's who reported highest stress levels were most accurate (88% compared to less stressed 75%) suggesting that anxiety doesnt have a negative effect on accuracy of EWT in the real world and may even enhance it
• how can we explain the contradictory findings?

  deffenbacher reviewed 21 studies of EWT and noted contradictory findings so used the yerkes-dodson law (inverted U) when we witness a crime/accident we are physiologically (fight or flight) and emotionally (anxiety) aroused, lower levels of arousal produces lower levels of accurate recall however theres an optimal (max) level of anxiety
• give one limitation of the study by johnson and soctt

  it may not have tested anxiety, p's only focused on weapon b they were surprised than scared. picklel made an experiment using scissors, handgun, or raw chicken in a hairdressing salon clip (scissors as high anxiety, low unusualness) EW accuracy was poor in high unusualness condition (chicken and handgun) this suggests that the weapon focus effect is due to unusualness than anxiety and therefore tells us nothing specifically about the effects of anxiety on EWT
• give one strength for support for negative effects

  anxiety does have a negative effect of recall. valentine and mesout supports weapon focus, they used heart rate to divide p's into high and low anxiety groups, anxiety disrupted their accuacy of recall on the actor in the london dungeon suggesting that high levels of anxiety has a negative effect on recall in stressful situations
• give one strength and its counterpoint for support for positive effects

  chistianson and hubinette interviewed 58 witnesses to a bank robbery there was bystanders and bank workers (direct involvement) the researchers assumed that those directly involved would have more anxiety but it was found that recall was more than 75% accurate, these findings from actual crimes confirm that anxiety does not reduce accurate recall and enhances it
• give one strength and its counterpoint for support for positive effects (2)

  counterpoint: they interviewed their p's months after and the researchers had no control over what happened after (PED) the effects of anxiety may have been overwhelmed by these factors and impossible to asses by the time the p's were interviewed therefore its possible that lack of control over confounding variables are responsible for these findings
• evaluation extra

  while the inverted U theory is a good explanation for contradictory findings it also ignores that fact that anxiety has many elements e.g cognitive and behavioural and assumes that physical arousal is the only aspect linked to EWT but the way we think in stressful events are important too