Transcript PP Memory and Eyewitness Testimony

And yet another memory test
Look at the following list of words
Try these words:
• List 1: read, pages, letters, school, study,
List 2: sheets, pillow, mattress, blanket,
reading, stories, sheets, cover, pen, pencil,
comfortable, room, dream, lay, chair, rest, tired,
magazine, paper, words
night, dark, time
Which of these words was on that list?
Which of these words was on that list?
door, tree, eye, song, pillow, juice, orange, radio,
house, pencil, apple, shoe, book, flag, rock, train,
rain, car, sleep, cat, dream, eat
ocean, hill, music, water, glass, school
Eye Witness Testimony
False memory
• Where people “remember”
things that they haven’t
actually seen or that haven’t
actually happened because of
planted suggestions
• It is one of the reason that
witness testimony is so
unreliable.
Witness testimony
TED talks: Elizabeth Loftus
Memory is a fragile thing…..
Recall is influence by incorrect information
• Loftus 1979: staged theft from handbag in a busy
train station
• A male accomplice pretended to steal something
• On return the women loudly shouted about her
tape recorder(think….recordable CD player)
being stolen
• 1 week later witnesses were interviewed
• 50% of witnesses recalled seeing a tape
recorded; some even described it
Taking Witness Testimony
• Misleading questions and information given to a
witness could result in inaccurate reconstruction
of memory
• Questioning must be done very carefully
• Loftus and Palmer(1974) investigated how the
wording of questions can influence eye witness
or prompt false memories
For example
Phrasing of a question can influence witness testimony?
How fast was the car going when they hit each other?
How fast was the car going when they contacted each other?
How fast was the car going when they collided with each other?
How fast was the car going when they smashed into each other?
How fast was the car going when they bumped each other?
Order these from that which elicited estimates of the cars
travelling at the highest speed to that which elicited estimates of
cars travelling at the lowest speed.
Suspect Identification through police ups
Why might a police line up be more effective at
helping a witness identify a suspect than them
looking at mug shots or police sketches?
Police Line Ups
• The line up needs to be carefully constructed
• Eg. Two eyewitnesses gave the following description of a
suspect in a robbery
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Late teens (15-16 years old, no more than 18)
Male Caucasian
Frizzy and curly hair
175-180 cm in height
Small build (~ 65-75kg)
• Which of the following males do you think is the suspect?
185cm
180cm
175cm
165
1
2
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3
4
The witness description again…
Late teens (15-16 years old, no more than 18)
Male Caucasian
Frizzy and curly hair
175-180 cm in height
Small build (~ 65-75kg)
5
6
When a similar study was conducted on a university
campus, the line-up almost guaranteed the selection
of one suspect. If a particular description can only be
applied to one suspect, then the line up is considered
to be biased.
1. Which suspect did you select based upon the
description? Explain why.
2. In a similar study, suspect number 5 was
most commonly selected by participants. Is
this consistent with your guess?
3. Why would this be considered a biased lineup?
4. What could be done to make this a fairer line
up?
Facial composites from witness
descriptions
• Witnesses are sometime called on to work
with identity police and sketch artists to
recreate the likeness of a suspect in an
investigation.
• How well is a witness is likely to remember a
face?
– Dependent of a number of factors including:
• Attention payed
• Stress of situation
How good is your memory for faces?
Find out with the Face Memory Test.
Go to
Face Memory Test - Version 2
See how you fare at recalling a face
• Where you able to accurately select the features of the face
you had “witnessed”
• If you were a witness to a crime trying to remember the
face of the perpetrator, suggest some factors might affect
your memory of the persons face?