Wells, G.L.,
Eyewitness identification is
an important, albeit complex, type of evidence used by police. While this method is ideal when the police
have both a witness and a suspect, many times the police have a witness but no
suspect and make use of special kits to build a composite face. These kits require witnesses to create a
composite by choosing from hundreds of features using a ‘particularistic’ as
opposed to a ‘holistic’ approach.
Although evidence seems to indicate that this impairs later judgment by
witnesses, previous research is relatively limited and underpowered. The experimenters predict a criterion shift
for those involved in creating a facial composite as well as impaired memory,
but were less certain about what would happen to participants merely exposed to
a composite.
Experiment 1:
Participants were randomly
assigned to a control, composite, or yoked composite-exposure (exposed to a
composite made by another person) condition.
In all conditions participants were randomly assigned to fill out a
questionnaire about one of fifty faces, and later they were asked to complete a
verbal description of the face. Next
participants in the composite condition were asked to build a composite of the
face using the FACES program. Those in
the yoked composite-exposure conditions were asked to view a composite created
by someone else who’d seen the same face.
48 hours later all participants were asked to identify the photo in a
six photo lineup and then rate their confidence. Those who did not choose were forced to make
a choice.
Participants in the control
condition were much better at identifying the target, and more confident than
either the composite or yoked conditions, although yoked participants fared
better than the composite group. (see Table 1) Further,
mistaken identifications were greater in the composite condition. When ten separate participants attempted to
match the composites to the faces in the photos, their hit rate was about 25%
Experiment 2:
Experiment 2 sought to test
the findings of experiment 1 on a target absent lineup, as well as increase the
forensic validity of the test by 1) having the original viewing of the face
take place in a dynamic video condition more like real crime scenarios, and 2)
having the participant identify a picture taken of the suspect in a different
outfit, with different facial expression, etc.
Participants were assigned to either a target
present or target absent condition, as well as a composite building or control
condition (yoked condition excluded in this experiment). Participants first viewed the video, then
provided a verbal description, then composite
participants used the FACES program to build a composite. 48 hours later participants returned and were
asked to identify the suspect in a lineup and rate their confidence. Again non-choosers made a forced choice
decision.
For the target present
condition, experiment 1’s results were replicated. For experiment 2, the correct rejection rate
for each group did not differ, but in the target absent condition confidence
rates did not differ between conditions either.
Discussion:
Mere exposure to a composite
face seemed to cause a criterion shift leading to reluctance to make an identification, but did not affect the original memory as
participants were still able to make a correct identification when forced. Although composite building does not increase
false identifications, it does significantly impair ability to make correct
IDs. It is still important to note that
wee still do not know if these effects are generalizable
to a police sketch artist, and it cannot be claimed that the use of such
procedures should be ended altogether.
Important Legal
Disclaimer: The preceding are articles we read together in the Lampinen Lab Spring 2006 false memory reading group. By
clicking on the button next to the article you can see the summary of that
article. The summary was prepared by the student presenting that article and it
is of course the case that the views expressed in the summary do not
necessarily represent the views of the reading group as a whole, Dr. Lampinen, the Lampinen Lab,
Hugo's, the University of Arkansas, the Razorback Football or Basketball teams
(although we're not sure about cross country), people living down the street
from us, Bob Dylan, Jack Fate, our extended families, or anyone else for that
matter except for the student who wrote the summary (and they don't necessarily
believe what they wrote either).