Forensic Psychology Flashcards
How can we think about what we mean by forensic psychology?
Applying psychological science to any aspect of the criminal justice system.
This includes:
Understanding why people commit crimes
Police investigations: best ways to ask questions
Court room - what evidence do jurys lead to
Whether a person is fit to stand trial
What we are trying to achieve by punishing people (jail etc)
What are three approaches in detecting deception?
Behavioural markers (non verbal) Speech analysis (verbal) Physiological markers
What do people think are signs of deception?
Non verbal: gaze aversion (looking away), increased body movements, fidgeting
Verbal: reduced detail in speech content, errors in speech content
How good are people at detecting deception?
“Ordinary people”: 57% accuracy rate (not very good).
Police, customs, officers: 56%
Secret service agents: 64%
CIA agents: 74%
Even best spies not very good
Why are professionals not much better at detecting lies?
Lack of interaction? Tested with watching video vs interrogate: only 56.7%
Stakes not high enough?
Why are we not good at detecting lies?
Relying on wrong cues.
Eg. Increased gaze aversion and fidgeting are NOT signs of lying
Giving incorrect explanations for behaviours
- acting nervous = lying or worries about proving innocence?
- avoiding eye contact = guilty? Shy? Cultural reasons?
Biggest reason: THERE ARE NO DEFINITE SIGNS OF LYING
On average, what’re some indicators of lying? However lying does not directly produce these effects!!!!
Lying may trigger emotions which may produce:
- higher voice pitch
- micro expressions
Lying takes a lot of cognitive effort:
- more errors
- less detail
- more structure in story
Attempted behaviour control:
- more rigid
- less expression
Can lie detection be improved?
Train people to look for specific markers
-lots of different techniques tried (ignore gaze aversion, minister pauses and errors, look for foot and leg movement)
Very little improvements (4%)
More effective, “active interviewing” techniques
Interacting in specific ways which have been shown to improve lie detection
promising approaches to improve lie detection
Falls under two classifications:
-increase cognitive load on person
-strategic use of information
What’re some “active interviewing” techniques?
- increase cognitive load
- unanticipated questions
- strategic use of information
Increasing the cognitive load to detect lies
Reverse order (tell the story in backwards events)
Maintain eye contact
Increase amount of information generated (example of evidence from another witness in unrelated case)
Aims to set the bar high with how much detail you’re able to produce
Different reporting modes (Tell me the story using pictures)
Increased frequency of errors and pauses
Better lie detection by professionals
What’re some potential drawback in increasing cognitive loads to detect lies
May increase amount of inaccurate information generated by truth tellers in interviews (especially when memory for event is poor)
Effectiveness might depend on working memory capacity of person being interviewed
(Ineffective for high working memory loads? Problematic for low working memory truth tellers?)
Unanticipated questions in detecting lies
Liars prepare well for interviews
Benefit reduced for unanticipated questions (cognitively easier for truth tellers than liars)
People anticipate “tell me what happened” etc
Don’t expect questions about spatial and temporal details “in relation to the front door, where was the nearest table”
Increased errors and lie detection (up to 80% accuracy)
