factors effecting EWT

• what are the two main factors that affect ewt?

  misleading information and anxiety.
• how does anxiety negatively affect recall?

  anxiety creates physiological arousal in the body which prevents us from paying attention.
• who researched into anxieties negative affect on recall?

  johnson and scott 1976
• describe johnson and scott's 1976 study.

  two groups of pps were sat in a waiting room.one group heard a casual conversation in a neighbouring room followed by a man entering holding a pen. the other heard an argument and breaking glass followed by a man holding a blood covered knife. pps were later asked to identify the man from 50 photos.
• what were johnson and scott's findings?

  49% who had seen the pen correctly identified the man. 33% who had seen the knife correctly identified the man.
• what is the explanation for why such a small proportion of pps identified the man with the knife in johnson and scott's study?

  the tunnel theory that argues people have enhanced memory for central details, e.g. their attention was focused on the knife instead of the man's face.
• how does anxiety positively effect recall?

  the fight or flight response is triggered, increasing alertness.
• who researched anxieties positive effect on recall?

  Yuille and Cutshall 1986.
• describe Yuille and cutshalls study.

  13 witnesses of a real life murder (shooting) were interview 5 months after the incident. their interview was compared to the original police interview. they were also asked to report stress levels on a 7 point scale.
• what were yuille and cutshalls findings?

  there was little change in the reports. those who reported higher anxiety had 88% accuracy. those who reported lower anxiety were 75% accurate. suggesting anxiety enhances EWTs.
• what is the yerkes dodson inverted U theory?

  medium levels of anxiety are ideal, too much and too little reduce accuracy.
• what support is there for the negative affects of anxiety on recall?

  Valentine and Mesout 2009pps were split into high and low anxiety on the bases of heart rate. low anxiety participants were significantly more accurate when asked to recall actors from the london dungeons labyrinth.
• what support is there for the positive affect of anxiety on recall?

  christianson and hubinette 1993 interviewed 58 witnesses to bank robbery. all participants had a 75% accuracy however those directly involved was even higher. however researchers had no control over PED so there is a possibility confounding variables are responsible for the findings, invalidating their research.
• what is the main weakness for anxieties effect on recall?


  there has been criticism that research done by johnson and scott may not have investigated anxiety but instead unusualness as the gun was unexpected.Kerri Pickel in 1998 showed 4 groups of participants a version of a video taken from a hairdressers where a client enters holding 1/4 objects - scissors, a wallet, a gun, or a chicken.eyewitness accuracy was significantly worse for the unusual objects - gun and chicken suggesting weapon focus effect is due to surprise rather than anxiety.
• what weakness is there for the inverted U theory?

  it ignore the fact that anxiety has many elements - cognitive, behavioural, emotional, and physical meaning the theory could be too simplistic.