Welcome to Criminal Psychology!
Welcome, future psychologists! In this chapter of Applied Psychology, we are going to dive into the minds of criminals, the way evidence is collected, and how the legal system works. We’ll explore why some people commit crimes, how the police can interview witnesses better, and whether prison actually works.
Criminal psychology is fascinating because it’s not just about what you see on TV dramas—it’s about using scientific evidence to make the world a safer and fairer place. Don't worry if some of the biological or legal terms seem tricky at first; we will break them down step-by-step!
1. What Makes a Criminal? (Biological)
Is a person born a criminal, or do they become one? This section looks at physiological (brain and body) and non-physiological (environment) explanations for crime.
Key Research: Raine et al. (1997)
Adrian Raine wanted to see if the brains of murderers were different from "normal" people. He used PET scans to look at the brain activity of 41 murderers who pleaded "Not Guilty by Reason of Insanity" (NGRI) and compared them to a control group.
The Findings: The murderers had reduced activity in the prefrontal cortex (the part of the brain that controls impulses and logic) and the amygdala (which processes emotion).
Analogy: Imagine the prefrontal cortex is the "brakes" of a car. If the brakes aren't working properly, it's much harder to stop the car from crashing when things get heated.
Quick Review: Brain Areas to Remember
Prefrontal Cortex: The logical "boss." Low activity = poor self-control.
Amygdala: The emotional "alarm." Low activity = less fear of consequences.
Application: Biological Strategies
If crime is partly biological, we can try to "fix" the biology. One strategy is nutritional intervention. Studies show that giving young offenders Omega-3 supplements can reduce aggressive behavior because it helps brain health.
Key Takeaway: Biology plays a role in crime, especially in how the brain handles impulses and emotions.
2. The Collection and Processing of Forensic Evidence
Fingerprints are often seen as the "gold standard" of evidence. However, humans have to analyze those prints, and humans can be biased!
Key Research: Hall and Player (2008)
The researchers wanted to know if emotional context (knowing a crime was a "brutal murder" vs. a "minor theft") would make fingerprint experts more likely to say a "smudged" print was a match.
The Findings: Surprisingly, the experts were not significantly affected by the emotional context when making their final decision. They remained professional! However, they felt they were affected by the stories they read.
Did you know? Even though experts are good at staying objective, "cognitive bias" is a real risk when evidence is unclear.
Application: Reducing Bias
To keep evidence objective, we can use blind testing. This means the person analyzing the fingerprint should not be told anything about the crime or the suspect. This prevents their "logical" brain from being "tricked" by their emotions.
Key Takeaway: Fingerprint experts are highly skilled, but keeping them "blind" to the case details ensures the highest level of fairness.
3. Collection of Evidence (Cognitive)
How do police get the best information from witnesses? Traditional police interviews can be leading or stressful, causing witnesses to forget details.
Key Research: Memon and Higham (1999)
This was a review of the Cognitive Interview (CI). The CI is a special way of interviewing that uses four main techniques to help people remember more.
The Four Techniques (Mnemonic: R.C.O.P):
1. Report everything: Tell every tiny detail, even if it seems useless.
2. Context reinstatement: Imagine you are back at the scene. What did it smell like? How did you feel?
3. Order change: Describe the event backward to prevent your brain from "filling in the gaps" based on expectations.
4. Perspective change: Imagine you were standing across the street. What would you have seen?
Application: Police Training
The best strategy for police is to use the PEACE model (Planning, Engage, Account, Closure, Evaluation). This ensures interviews are ethical and not "suggestive."
Key Takeaway: Memory is like a puzzle; the Cognitive Interview helps witnesses find the pieces without the police accidentally "drawing" on the puzzle for them.
4. Psychology and the Courtroom
Even if the evidence is good, a jury might be persuaded by things that shouldn't matter—like a person's accent or how they look.
Key Research: Dixon et al. (2002)
Dixon investigated if a Brummie accent (Birmingham) made a defendant look more guilty than a "Standard English" accent.
The Findings: Participants rated the defendant with the Brummie accent as significantly more guilty than the one with the Standard accent. This was even worse if the crime was a "blue-collar" crime (like armed robbery) and the defendant was described as black.
Common Mistake to Avoid: Remember that this study shows perceptions of guilt, not whether the person was actually guilty!
Application: Influencing the Jury
Lawyers use presentation styles to influence juries. For example, using "story order" (presenting evidence in a timeline) is much more effective than "witness order" because it helps the jury build a mental picture of what happened.
Key Takeaway: Juries are human and can be influenced by stereotypes (like accents). Using a clear "story" format can help them focus on the facts.
5. Crime Prevention (Social)
Can we stop crime just by fixing the neighborhood?
Key Research: Wilson and Kelling (1982)
They proposed the Broken Windows Theory.
Analogy: Imagine a building with one broken window. If it isn't fixed, people think "nobody cares about this building." Soon, all the windows are broken, and then people start tagging it with graffiti.
The Logic: Small signs of disorder (litter, broken windows, public drinking) lead to a fear of crime. Law-abiding citizens stay indoors, and criminals feel "safe" to commit more serious crimes because they think nobody is watching.
Application: Zero Tolerance
The strategy here is Zero-Tolerance Policing. Police crack down on minor crimes (like jumping subway turnstiles or littering) to show that the authorities are in control. This "nips it in the bud" before big crimes happen.
Key Takeaway: A clean, well-lit, and cared-for neighborhood makes people feel safe and discourages criminals.
6. Effect of Imprisonment
What happens when we lock people up? Does it make them "better," or just "better criminals"?
Key Research: Haney et al. (1973) - The Stanford Prison Experiment
Haney (and Zimbardo) set up a simulated prison. Students were randomly assigned to be either "prisoners" or "guards."
The Findings: The experiment had to be stopped after just 6 days! The guards became cruel and abusive, and the prisoners became depressed and passive. It showed that the situation (being in a prison environment) is more powerful than a person's individual personality.
Don't worry if this seems extreme: This study is often criticized for its ethics, but it is vital for showing how prison environments can change human behavior.
Application: Reducing Reoffending
To stop people from going back to prison (recidivism), we use strategies like Restorative Justice. This involves the criminal meeting the victim to see the real-life harm they caused. It targets the social side of crime by building empathy.
Key Takeaway: Prison is a powerful environment that can cause negative psychological effects. Rehabilitation (like restorative justice) is often more effective than just "punishment" for long-term change.
Quick Summary Checklist
• Biological: Raine (Brains), Omega-3 (Fixing the brain).
• Forensic: Hall and Player (Expert bias), Blind testing (Stopping bias).
• Cognitive: Memon and Higham (Cognitive Interview), RCOP (Memory techniques).
• Courtroom: Dixon (Accents), Story Order (Winning the jury).
• Social Prevention: Wilson and Kelling (Broken Windows), Zero Tolerance (Clean streets).
• Imprisonment: Haney (Stanford Prison), Restorative Justice (Healing the harm).