Identifying the bad guy
Flinders University psychologist Professor Neil Brewer is proposing a radical alternative to the traditional police line-up, arguing current eyewitness identification tests often fail to pick the culprit, or worse, wrongfully accuse innocent suspects.
Professor Brewer, Dean of the School of Psychology, has devised a new type of line-up where witnesses are simply asked how confident they are that each line-up member is the culprit, and must respond within a few seconds, rather than trying to point out the perpetrator and having more time to mull it over.
His technique, called “deadline confidence judgements”, has been trialled on more than 900 community members, with the results soon to be published in Psychological Science, one of the world’s most influential psychology journals.
In several experiments conducted over the past three years, Professor Brewer said volunteers watched short films depicting crimes or a mundane event in which one person was prominent.
Half of the participants – some a week later and others within five minutes of the films – were then shown a series of individual pictures from a line-up of 12 people and asked to make a confidence decision about each face within three seconds of it appearing on the computer screen.
They were asked to choose one of 11 options, ranging from “absolutely confident that this is the culprit” to “absolutely certain this is not the culprit”, while the other half of the participants were shown the same faces but given as long as they liked to answer whether each face was or was not the culprit. Sometimes the photos included the culprit and sometimes they did not.
Professor Brewer said a classification “algorithm” produced overall classification accuracy that was 20 to 30 per cent higher than results produced with the conventional line-up.
Moreover, he said the researchers were able to identify particular patterns of confidence judgments across lineup members which showed either a very high or very low likelihood that any individual witness was accurate.
Limiting the time witnesses had to look at suspects yielded better results, Professor Brewer said, because past research showed accurate eyewitness identifications were made significantly faster than inaccurate ones, and that a number of outside factors were removed with a short deadline.
“A weakness of the traditional test lies in the fact that it requires a witness to make a single yes or no decision about a line-up, with plenty of time to reflect on their decision,” Professor Brewer said.
“But the time lapse from the initial viewing to the response often mitigates against witnesses making accurate decisions, as does an array of external factors such as the quality of viewing conditions, attention constraints and social cues that bias the witness towards a positive identification – for example “I saw him for a long time so I should know the answer”.”
Professor Brewer said traditional identification tests often failed because the witness felt “under pressure” to identify a guilty party, however his study showed they were more likely to make accurate identifications if they did not have to be so precise.
“A victim of an assault, for example, has plenty of time to reflect on their decision so they’re more likely to think “if I don’t pick this person, a dangerous man may go free or if I do pick the suspect I’d better be right”, but in a deadline confidence judgement you’re not asking for a yes or no answer.”
Professor Brewer said the rising number of DNA exonerations and the frequent failure of witnesses to identify the culprit mounted a compelling case for a new system of line-ups.
“The fallibility of eyewitness evidence has been consistently highlighted in lab and field studies, and the potency of mistaken identifications has also been dramatically highlighted by the number of DNA exoneration cases,” he said.
Provided by Flinders University
- Cotton thrips posed big problem for some South Plains farmers Jan 02, 2012 | not rated yet | 0
- Researcher uses card trick to reveal unconscious knowledge Nov 17, 2011 | not rated yet | 0
- Cornell researchers striving to understand memorable movie quotes Apr 04, 2012 | not rated yet | 0
- Scientists use frogs to battle superbugs Mar 19, 2012 | not rated yet | 0
- Study of Facebook patterns suggests interests in music, movies unlikely to spread among friends Jan 19, 2012 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Pressure-volume curve: Elastic Recoil Pressure don't make sense
14 hours ago From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
Marie Curie's leukemia
May 13, 2013 Does anyone know what might be the cause of Marie Curie's cancer
- More from Physics Forums - Medical Sciences
More news stories
The latest makeover to a massive psychiatric tome honored by some, reviled by others and even called the "Bible" of mental disorders is being released Saturday with a host of new changes.
Psychology & Psychiatry 5 hours ago | not rated yet | 0
(HealthDay)—Most Medicare beneficiaries treated in inpatient psychiatric facilities (IPFs) exhibit characteristics associated with hospital readmission, according to a report prepared for the National Association ...
Psychology & Psychiatry May 17, 2013 | not rated yet | 0
Skydivers show the same level of physical stress before every jump whether a first-timer or experienced jumper, say Northumbria researchers.
Psychology & Psychiatry May 17, 2013 | not rated yet | 0 |
Children of depressed parents pick up on their parents' sadness—whether mom or dad realizes their mood or not.
Psychology & Psychiatry May 17, 2013 | 4.5 / 5 (2) | 1 |
(HealthDay)—As many as one in five American children under the age of 17 has a diagnosable mental disorder in a given year, according to a new federal report.
Psychology & Psychiatry May 16, 2013 | 2.2 / 5 (5) | 1 |
An increasing number of U.S. children are experiencing gastrointestinal issues that require interventions to resolve, according to research presented at Digestive Disease Week (DDW).
7 hours ago | not rated yet | 0 |
A new case of the deadly coronavirus has been detected in Saudi Arabia where 15 people have already died after contracting it, the health ministry announced on Saturday on its Internet website.
5 hours ago | not rated yet | 0
Big names in medicine are set to give an upbeat assessment of the war on AIDS on Tuesday, 30 years after French researchers identified the virus that causes the disease.
15 hours ago | 5 / 5 (1) | 0
For combat veterans suffering from post-traumatic stress disorder, 'fear circuitry' in the brain never rests
Chronic trauma can inflict lasting damage to brain regions associated with fear and anxiety. Previous imaging studies of people with post-traumatic stress disorder, or PTSD, have shown that these brain regions can over-or ...
16 hours ago | 5 / 5 (1) | 0 |
A ground-breaking advance in colonoscopy technology signals the future of colorectal care, according to research presented today at Digestive Disease Week(DDW). Additional research focuses on optimizing the minimal withdrawal ...
7 hours ago | 5 / 5 (1) | 0