1. Impairs - From a review of 21 studies, Deffenbacher (2004) looked at the effects of heightened anxiety and the accuracy of eyewitness recall. It was clear that there was considerable support for the hypothesis that stress negatively impacted the accuracy of EWT, meaning that a person's memory was affected if they became too anxious.
2. Impairs - Weapon focus effect, which states that anxiety focuses a person's attention on central details rather than any peripheral factors. This is backed up by the 'Loftus et al' study of 1987, in the condition involving a weapon, participants wereless likely to remember a person's face/dress than those faced with no such weapon.
3. Improves - Christianson and Hubinette (1993) interviewed 58 witnesses to real bank robberies. They found that those who had been directly threatened were more accurate in their recall than those who had been onlookers and therefore less emotionally aroused. This continued to be true even some 15 months later.
Age of Witness
1. Lindsay and Poole (2001) engaged children aged 3-8 in a science demonstration. Their parents then read them a story which contained new, contradicting information to the science demonstration. After being questioned, researchers found that the children had incorporated much of the new information into their original memory (post-event effect). In another phase, the children were asked to recall where they got this information from (source monitoring); older children then reverted back to the original memory and removed all post-event information, whereas younger children seemed unable to do so, this shows that younger children are bad at source monitoring.
2. Flin et al (1992) questioned a series of children and adults one day after an incident, and then again 5 months later. There were no differences after one day, but over time they emerged. There was a significant amount of forgetting among the children, when compared to the adults. This is problematic as court proceedings oftern take place many months after the events occured.
3. Own age bias - Most tests are done on college-aged students, and they're shown photos of similarly aged people. When comparisons are made, older adults are shown the same sample of photographs - most research into EWT ignores the fact that we may have a superior memory for those in our own age group. This is backed up by the 'differential experience hypothesis', which states that the more contact we have with a particular age/ethnic group, the better our memory is for such individuals.