Eyewitness Testimony & Deception Detection

Deception and Lie Detection

• Nonverbal behaviors are generally unreliable for detecting deception due to individual differences.
• Meta-analyses have shown no overall effect of nonverbal cues on deception detection.
• Verbal indicators of lying include higher voice pitch, slower speech, and more language disturbances.
• Trained individuals are generally unable to accurately detect deception through observation alone.
• The US Secret Service Agents are an exception, but their accuracy is still not perfect.
• Additional information beyond behavior improves deception detection.
• Expectation and investigator bias can negatively impact accuracy.
• Microexpressions may help detect deception, but this finding is not consistently reproduced.

The Polygraph Technique

• Polygraph machines measure autonomic nervous system responses to infer deception.
• Measures physiological states associated with lying via dry mouth, sweat, increased heart rate, breathing.
• Training in using polygraph devices is offered at the Canadian Police College.
• The Canadian Police College has an intensive 10-week course on using the devices, interviewing techniques, and scoring the test.
• Polygraphs are used in criminal and insurance investigations, custody and family law, and as a screening tool.
• Polygraph disclosure tests aim to uncover details about past behavior, such as parole violations.
• A study by Bourke et al. (2015) showed a significant increase in sex offenders disclosing past abuses during a polygraph test.

Types of Polygraph Tests

• Comparison Question Test:
  • Neutral questions are mixed with emotionally arousing comparison questions and relevant questions about the crime.
  • The examiner asks "yes" or "no" questions about neutral topics, probable lies, and facts relevant to the case.
  • Innocent people react more to comparison questions, while guilty people react more to relevant questions.
• Concealed Information Test:
  • Assesses if the suspect knows details about the crime that only the perpetrator would know.
  • It relies on the principle that people react differently to new and familiar information.

The Validity of Polygraph

• Polygraphs are not always reliable in detecting lies as irrelevant high-arousal emotions can cause false positives.
• Medications can affect physiological responses, and individuals can learn to beat the polygraph.
• Examiners' biases can influence the questions asked and the interpretation of data.
• Patrick and Iacono (1991) found polygraphs were better at detecting physiological responses than distinguishing liars, with a high false positive rate.
• Elaad et al (1994) showed that prior expectations influence how examiners ask questions and interpret polygraph data.
• Polygraphs are generally not admissible as evidence in court due to lack of scientific rigor.

Approaches with Imaging Techniques

• Electroencephalograms (EEGs) are used to detect deception by examining event-related potentials (ERPs).
• ERPs are electrical patterns produced by brain activity in response to a stimulus or event.
• P300 brain wave may signal a reaction of surprise
• EEGs face similar issues to polygraphs, including vague results, impracticality, interpretational challenges, and low sample sizes due to high costs.

Deception in Clinical Settings

• Involuntary lying includes conditions where individuals believe they are truthful or cannot control their lying.
• Voluntary lying involves intentionally faking symptoms for personal gain.

Involuntary: Conversion Disorder

• Individuals experience neurological symptoms (e.g., blindness, paralysis) not caused by medical conditions.
• Psychological factors, such as stress, cause the symptoms
• Not intentional

Involuntary: Factitious Disorder

• Intentional production of symptoms (physical and/or psychological) without external incentives to do so.
• People are aware that they are lying about the symptoms but unaware of their need to do so.

Borderline: Munchausen Syndrome by Proxy

• Intentional production of illness in someone under their care/leads others to believe that someone under their care is ill
• Most common example is mothers victimizing their children.
• The goal is sympathy and attention for the adult in charge.

Voluntary: Malingering

• Malingering is faking physical or psychological symptoms for personal gain due to internal or external motivation.
• Estimated rates of malingering vary from 17-21% in low severity pre-trial populations to 45-64% in incarcerated populations.
• External motives for malingering include avoiding punishment, seeking drugs, avoiding duty, financial gain, and free accommodation.

Malingered Psychosis

• Instrumental psychosis involves feigning symptoms to gain special accommodations, such as psychiatric care.
• Structured Interview of Report Symptoms (SIRS) is an interview-based method with 172 items scored across eight subscales.
• Self-report questionnaires, such as the MMPI-2, include malingering scales like the Infrequency (F) scale.

Studying Malingering

• Simulation Design:
  • Researchers use simulation designs with control, clinical comparison, and experimental groups to study malingering.
  • Experimental groups may include some people who do not have the mental disorder and malinger symptoms and others that have the mental disorder and malinger symptoms they do not have.
  • These studies have high experimental rigor but may lack ecological validity due to participants' limited knowledge of symptoms.
• Known-Groups Design:
  • This design compares genuine patients and malingerers to analyze similarities and differences.
  • It's rarely used due to difficulties in identifying "true malingerers" and the risk of including malingerers in the "genuine patient group."

Eyewitness Evidence

• Eyewitnesses are relied on heavily, but it is important to understand:
  • The limitations of memory
  • To best preserve memory for people/details involved
  • How to distinguish between reliable and unreliable recollections
• Memory processes involve encoding, storage, and retrieval.

Retrieval: Recall vs Recognition

• Recall:
  • Generating information previously witnessed, with or without prompts/clues
• Recognition:
  • Judging whether something currently presented has been seen before

Improving Witness Recall

• Cognitive Interview:
  • An interview protocol for cooperative witnesses that increases the amount of accurate information recalled.
  • Relies on multiple retrieval paths to establish different angles.
  • Relies on feature overlap, in which recall improves when encoding and retrieval contexts are similar
• Components of Cognitive Interview:
  • Mental Context Reinstatement: Mentally place witness at event
  • Report Everything: Report every single thing, no detail is unimportant
  • Change Order: Recall event in different sequence
  • Change Perspective: Recall event from a different perspective
• Components of Enhanced Cognitive Interview:
  • Interviewer build rapport first
  • Interviewer visibly be attentive and not interrupt
  • Witness control the pace/flow of the interview
  • Open-ended questions first, followed by focused techniques
  • Interviewer asks focus questions about current topic

Threats to Accurate Recall

• Memory is self-correcting and updated with new information.
• The misinformation effect happens when a witness exposed to inaccurate details between encoding and retrieval incorporates them into their memory.

Studying the Misinformation Effect

• Classic study: Loftus and Palmer (1974):
  • Participants view a slide show of a car driving past a yield sign
  • Questioning suggested presence of a stop sign instead
  • More than half of participants misremembered seeing a stop sign
• encoding - staged event or video
• storage - experimental group (post-event info) and control group (no post-event info)
• retrieval - memory test

Why Does the Misinformation Effect Occur?

• Source Misattribution Hypothesis:
  • Witnesses recall both pieces of info but cannot recall which is from the original event
• Memory Impairment Hypothesis
  • Original memory has been replaced or altered

Eyewitness ID and Wrongful Conviction

• Eyewitness identification is the leading cause of wrongful convictions (64%).
• It is followed by invalid forensic science (52%) and then police misconduct (35%).

Case: Ronald Cotton

• Cotton was wrongly convicted of SA and breaking in
• The victim ID'd him from 2 line-ups
• Bobby Poole was later proven to be the real offender

Studying Eyewitness Recognition

• Researchers change retention interval aspects of the event or test to see how it affects eyewitness accuracy, confidence, and behavior.
• Retrieval memory test or ID procedure involves the true culprit, or an innocent suspect

Types of Identification Procedures

• Showup:
  • Present one person to the witness, face-to-face under suggestive circumstances.
  • Bad method because it makes it obvious who the suspect is
• Simultaneous Lineup:
  • Surrounds suspect with known innocent people (fillers)
  • Good procedure and very effective
• Sequential Lineup:
  • Go through a list of people one-by-one, pausing on each one and asking if this is the person
• Simultaneous lineup leads to relative judgment, a choice of lineup member that best matches memory relative to others
• Sequential lineup leads to absolute judgment - choose lineup member if match to memory exceeds a decision criteria

Classifying Lineup Decisions

• Ground truth: experimenters already know
• Miss is bad because the suspect keeps doing their thing
• False alarm is wrongful conviction, and the real suspect keeps doing their thing

Lineup Decisions

• Willingness to choose someone from the lineup irrespective of certainty or match to memory = response bias.
• Strategies to check if eyewitnesses have a low response bias (they'll pick anyone):
  • Blank lineups: Start with a target absent lineup and hope they'll reject it (all fillers)
  • Backloading: Make it seem like there are more photos in a sequential lineup

Studying Eyewitness Recognition

• Estimator Variables: Affect the likelihood of an accurate eyewitness ID (viewing conditions, intoxication, stress).
• System Variables: Contaminated memory or eyewitnesses perception of their memory (post-event information; interviews).
• Reflector Variables: Poorly qualified ID reduce accuracy/increase mistaken ID (biased lineup, instructions).

Can We Study Real Cases?

• Mistaken filler identifications occur in ~1/3 of real cases.
• Reflector variables: (behaviours during ID procedures that reflect the accuracy of the eyewitness' decision such as confidence, decision time, and wavering).
• The association between reflector variables and accuracy changes if recommendations relevant to system variables are not followed

Basics of Eyewitness ID Science

• Wells et al. (2020) - nine recommendations

1. non- suggestive prelineup interview
2. evidence based suspicion before putting a suspect in a lineup
3. double-blind administration
4. careful lineup filler selection to avoid biased lineups or confusion
5. prelineup instructions to prevent uncertain choosing
6. obtain an immediate confidence statement
7. video record procedure
8. avoid repeated identification attempts
9. recommendations for showups

• Post-identification feedback effect: when someone's confidence increases due to police feedback after choice

Manson Test (USA)

• Suggestive procedure but is it reliable?
• Look at circumstances:
  • Witness' opportunity to view the culprit
  • Witness' level of attention
  • Accuracy of the previous description of culprit
  • Witness' degree of certainty
  • Delay between crime and identification

Turnbul Test (Canada)

• A - amount of time observed
• D - distance
• V - visibility
• O - observation impeded
• K - known, seen before, how often
• A - any special reason to recall
• T - time between the event and ID
• E - error in description, relative to appearance of defendant

Psychologists as Expert Consultants in Criminal Cases

• Not common
• New Zealand is one of "substantial helpfulness"

R v. Watson

• The Backdrop*
• New Year's Eve 1997: hundreds of people attend a New Year's Eve party at Furneaux Lodge. Afterwards, Olivia Hope and Ben Smart go missing.
• Witnesses*
• Hundreds of witnesses at the party, but only 5 on the water taxi ride they were last seen on:
  • Guy Wallace
  • Amelia Hope
  • Rick Goddard
  • Sarah Dyer
  • Hayden Morresey
• Guy Wallace*
• Drove the boat on which Olivia, Ben, and unknown man were last seen and said he served unknown man drinks that evening
• Said the man was "scruffy" with longish, dark wavy hair, unshaven, and smelled or bourbon
• Hayden Morresey*
• On boat entire time and described unknown man.
• Description consistent with Wallace and composites: scraggly, dark hair down to shoulders
• Scott Wallace suspected*
• Attended the party alone, was drunk, and trying to hook up
• Didn't match description
• Montage B (line-up)*
• Police saved the key witnesses for this montage. This Montage was created with a "better" photo that was a "good likeness to Watson"
• Only 1 person ID'd Watson: Guy Wallace
• Trial and conviction*
• Found guilty in 1999 due to eyewitness evidence
• mtDNA evidence from two hairs were the main pieces of evidence and the hair was allegedly contaminated
• New Info to Jury in 1999*
• Montages shown to jury was not what happened
• Crown in argued that it was "more likely than not" that Wallace was shown this picture (showup)
• Wallace initially interviewed for 3.5 hours
• Crown and police dispute that Wallace was shown a montage

Eyewitness Issues in the R v Watson Case

• Evidence shows an increase in innocent suspect identification is likely when administered by someone not blind to the suspect's identity.
• Witnesses are exposed to post-event information relevant to the identity of the suspect from the media or witness accounts.
• The lineup is biased towards the suspect.
• The witnesses have already seen pictures of the suspect (repeated identification attempts).
• There was research showing that accurate eyewitnesses ID quickly , with high confidence, and with no wavering.

Conclusion About the Strength/Value of the Eyewitness Evidence

• The memory was contaminated by two prior instances where his face was shown and they said he was a suspect.
• The lineup was biased/administered non-blind
• Several non-identifications from Wallace/Hayden

This lesson explores eyewitness testimony, system vs estimator variables, and legal tests for admissibility. It also discusses the challenges of deception detection based on verbal and nonverbal cues, highlighting the limitations of observational methods.