factors affecting accuracy of EWT: anxiety Flashcards
how does anxiety have a negative effect on recall? (weapon focus)
-presence of weapon creates anxiety - leading to focus on weapon, reducing witness recall for other events
what was the procedure in johnson and scott weapon focus study?
-Ps in a lab study
-low anxiety conditon heard argument next door and man walk past them w pen in hand with grease
-other Ps heard heated arguement w breaking glass sound , man walked out knife covered in blood
-high anxiety conditon
what was found in johnson and scotts weapon focus study?
-from pctures of men, 49% were able to identify the man carrying pen
- 33% able to identify the man w a knife
-tunnel theory- ppl have enhanced memory for central events
in high anxiety condition = people focused more on the weapon due to anxiety.
how does anxiety have a positive effect on recall?
-flight or fight is triggered
-this increases alertness
-improve memory as u become more aware of cues
what was the procedure of yuille and cutshall for positive recall?
-conducted an actual shooting
-shop owner shot theif dead
-21 witnesses
- interviewed 4-5 months
- accuracy determined by number of details reported on each account
- witnesses asked to rate how stressed they had felt at the time and whether they had emotional problems since the event ( e.g sleeplessness)
what was the findings of yuille and cutshall?
-very accurate in accounts
-less accurate in details e.g age/ height/weight
- those w high level stress were most accurate(88%)
- 75% accuracy for less stressed
so anxiety may enhance EWT
what are the contradictory findings?
-yerkes dodson= emotional arousal and performance looks like an “inverted U”
-deffenbacher looked at 21 studies and noted contradictory findings
-we witness a crime or accident we become emotionally and physiologically aroused
-memory becomes more accurate when level of anxiety/ arousal increases
-there is an optimal level of anxiety (point of max accuracy )
- if a person experiences any more arousal then their recall declines drastically
-moderate anxiety is helpful
Parker et al and natural disasters?
Natural disasters- most lab based and real life studies of anxiety is that only that compare high and low anxiety groups
-Yerkes and dodson law can’t be tested properly unless there’s moderate group too
- parker et al=decided to overcome this and interview people apart of a hurricane andrew (1992) in USA.
researchers defined anxiety in terms of amount of damage the Ps suffered to their homes
what did parker et al find?
-found a link between the level of recall and amount of damage/anxiety
-parker’s study shows that higher anxiety is linked to better recall
-supported Yuille and cutshall but contradicts Yerkes and dodson
what are the strengths?
(support for negative effects)
-valentine and mesout study support weapon focus
-researchers used objective measure of heart rate to divide Ps into high or low anxiety groups
-anxiety clearly disrupted the Ps ability to recall details ab the actor in london dungeon labyrinth
- so high level anxiety in a stressful event impacts recall
(supports for positive effects)
-christiansen and hubinette interviewed 58. witnesses to actual bank robberies
-some directly involved and other indirectly
-researchers assumed those involved would experience most anxiety
-75%accuracy across all witnesses
-those involved were more accurate
-anxiety enhances recall
what were weaknesses?
(unsualness not anxiety)
-johnson and scott may have not measured anxiety
-Ps may have been shocked at what they saw rather than scared
-Pickel conducted a study with scissors, hand gun, wallet or raw chicken in a hair dressing video
- scissors would be high anxiety (low unusualness)
-EWT was poorer in situations w the raw chicken and handgun (high unusualness)
-weapon focus affect due to unusualness rather than anxiety
(counterpoint to support for positive effects)
-Ps were interviews several months after the event
-researchers had no control over what happened to them in the intervening time (e,g post event discussions)
-effects of anxiety possibly overwhelmed by other factors
-lack control of confounding variables
- some evidence goes against yerkes and dodson
(ethical issues)
-scary and traumatising for individuals part of the shooting
-ethically immoral
