Anxiety creates physiological
arousal, so concentration is worse
Johnson and Scott, 1976
Participants thought they were going to do a lab study.
While in the waiting room, they witnessed an argument
Low anxiety condition
Argument- man with pen and grease
49% recognition of suspect
High anxiety condition
Argument- broken glass- knife and blood
33% recognition of suspect
Tunnel theory- focus on weapon
Positive effect
Fight or flight response increases alertness
Yuille and Cutshall, 1986
Studied a real life shooting in a gun shop in
which the shop owner shot the thief dead.
The witnesses were interviewed 4-5 months after the event. Accuracy was
determined by how many details they could recall, and they were also asked
to rate how stressed they were, and if they had any emotional problems
The witnesses were very accurate in their accounts, with little change from
5 months previous. Those who reported high stress levels were more
accurate than those who reported low levels (88% compared to 75%)
Explanation of contradictory evidence
Yerkes and Dodson, 1908
The relationship between performance and
emotional arousal is an inverted U
Deffenbacher, 1983
Low levels of anxiety led to low levels of recall, while
too much anxiety also led to low levels of recall
There is an optimal level of anxiety
to ensure best performance
Evaluation
Weapon focus effect may be irrelevant
Surprised at what they see, not scared
Pickel, 1998
Used handgun, raw chicken,
scissors or a wallet
Recall was worse with the
more unusual objects
Raw chicken and handgun
Field studies lack control
e.g. post event discussion, news in the media
Extraneous variables may be responsible for results
Ethical issues
Psychological harm
Inverted U is too simplistic
Anxiety is not just physical, but also
cognitive, behavioural and emotional