Forensic Psychology

Intro to Psych

what is forensic psychology?

an application of psychological knowledge/ methods to the task of facing the legal system

has overlaps with other areas of psychology (cognitive, social, clinical, developmental) and law

what does it involve research about?

understanding criminal behaviour

the psychological aspects of legal processes

what is the early theory of criminality?

Lombroso (1870): claimed criminals had distinct physical features (an atavistic form)

primitive subspecies

e.g. asymmetrical face, ears of unusual size, prominent jaw/ cheekbones

criticisms= racist, primitive is outdated

however his theory did spark interest in linking biology with criminals

what are the biological explanations of criminality?

the brain and crime: the brain plays a major role in regulating behaviour, including aggression and impulse control

the prefrontal cortex regulated the amygdala, but in criminals it isn’t doing enough to regulate; leading to impulsive, aggressive or antisocial behaviour

overactive amygdala= heightened aggression/ fear reactions

underachieve amygdala= reduced fear conditioning, linked to psychopathy

what makes a criminal- biological?

Raine et al (1997): brain scans of murdered showed reduced prefrontal activity compared to controls

Yang and Raine (2009): meta-analysis- structural and functional prefrontal cortex deficits were consistently found in antisocial/ violent individuals

criticisms= causation vs correlation, not all violent criminals show prefrontal cortex deficits. small sample sizes, ethical forensic concerns

nature vs nurture?

the Stanford prison experiment (1971)- situational pressures and peer dynamics can override personality and individual traits

MAOA gene and childhood maltreatment- provides instructions for an enzyme which breaks down neurotransmitters (serotonin, dopamine, norepinephrine). Low activity variant (MAOA-L) leads to less enzyme, higher levels of neurotransmitters, so links to increased aggression and impulsivity

Caspi et al (2002)- men with MAOA-L variant who experienced child maltreatment were more likely to develop antisocial behaviour

genetics can predispose someone to aggression bye environment can amplify or mitigate the effect

what is an eyewitness testimony?

the verbal or written recollections of events witnessed by someone

they are central to criminal investigations and court cases

often unreliable due to memory falliability

Loftus and Palmer (1974)- leading questions

confidence vs accuracy- EWT memory?

high confidence doesn’t always = a correct memory

attention plays a key role

what is inattentional/ change blindness?

failing to see something that is fully visible because attention is directed elsewhere

attention is selective, limited processing capacity- your brain prioritises one task and ignores others

real world relevance: drivers missing motorcyclists/ pedestrians while focusing on traffic lights or phone

witnesses missing key details in crimes

memory for faces?

good at recognising familiar faces because we have good reference for them. recognition is autonomic and fast

much harder to recognise unfamiliar faces- accuracy drops dramatically

people often struggle to match two photos of the same unfamiliar person

CCTV identification is particularly unreliable

what is the cross-race effect?

Malpass and Kravitz- people are generally better at recognising faces of their own ethnicity

important forensic implications > high risk of wrongful identification across race

what are super recognisers?

these are individuals with exceptionally strong face recognition ability

they are estimated to be 1-2% of the population

increasingly used in policing and security

Russell et al (2009): some people score fae above average on face recognition tests

limitations= not infallible- still affected by context, stress and bias

what is prospangnosia?

face blindness

these are individuals with exceptionally poor face recognition ability

usually linked to damage or dysfunction in the fusiform face area

correctly picking someone from a lineup?

use measures of their general face recognise ability to see where they fall on the spectrum

see if they constantly identify them

use double-blind line ups