biological explanations Flashcards
what is atavistic form
Lombroso observed physical characteristics concluded criminals were ‘genetic throwbacks’ - a primitive sub species
Argued criminals were born rather than made
what was Lombrosos research
- examined facial and cranial features of hundreds of Italian prisoners
- 383 skulls of dead criminals and 3839 of living ones
- concluded 40% criminals had atavistic charactitics
What are some typical atavistic characteristics
- Narrow sloping brow, strong prominent jaw, high cheekbones, facial asymetry, dark skin
- Murders described as having bloodshot eyes, curly hair, long ears
Strengths of atavistic form
Lombroso credited for shifting emphasis in crime research away from moral explanations ( where offenders judged as being weak minded wicked) to a more scientific and credible idea. Additionally in trying to describe how different types of people are likely to commit different types of crime, his theory could be credited at begining of offender profiling. Theory a major contribution to science of criminology emphasimg importance of using research vidence. Although theres problems with his research lombroso infleuntial.
3 key studies within the genetic explanation
Twin studies- first criminal twin study conducted by JOHANNES LANGE who investigated 13 identical and 17 non identical twins, where on twin in each had served time in prison. She found 10 of the identical but only 2 of non had a co- twin that was also in prison. Concluding genetic factors must play a predominant role in offending behaviour
Adoption studies- CROWE found that adopted children who had a biological parent with a criminal record had a 50% chance of having a criminal record by age of 18, whereas adoptive children only had a 5% chance.
Candidate genes - Researcher carried out a genetic analysis of almost 900 offenders and revealed abnormalities on two genes that may be associated with violent crimes ( MAOA) - controls dopamine and serotonin and ( CDH13)- linked to substance abuse. Individuals with this high risk combination were 13x more likely to have a history of violent behaviour
- research is in its infancy so has not been replicated
how does the diathesis stress model link to the genetic explanation
- an approach to explaining behaviour which states that behaviour is the result of an underlying predisposition which is stimulated by a psychological trigger
- For criminal behaviour the biological predisposition is genes and the psychological trigger is criminal role model environment
Evaluation of the genetic explanation
weakness- Early twin studies like Lange’s were poorly controlled judgments about whether twins were MZ or DZ based on appearance. MZ twins often share more similar environments as treated more similar by everyone. Acts as a confounding variable. Lacks validity
Strength - adoption studies have shown that the percentage of convictions in adoptees was highest when both the adoptive and biological parents had convictions. Supports that genes and environment have an influence. Supports diathesis stress model. Some problems with adoption studies as some adoptees spend more time with biological parents before being adopted makes it difficult to assess influence of environment.
What is the neural explanation to offending
Evidence suggests there may be neural differences in the brains of criminals. Most evidence based on study of individuals with APD ( antisocial personality disorder ) which is associated with reduced emotional responses and lack of empathy.
who did research into the prefrontal cortex
Raine
- studied the volume of grey and white matter in the prefrontal cortex in 21 people with and without APD.
- measured using an MRI scan
- Found a reduced amount of grey matter in prefrontal cortex area for the APD group in comparison to control
- Shows there’s a link between violent offenders and volume of prefrontal cortex
What are mirror neurons
- Special brain cells distributed in several areas of brain.
- Allow us to interpret emotion and intention in others
- Recent studies show people with APD can experience empathy they do so more sporadically then rest of us ( empathy region activated when told to emphasise 0
- shows individuals with APD can show empathy but may have neural switch that can be turned on and off
what are the two neurotransmitters involved in offending behaviour
Serotonin - this neurotransmitter has been linked to mood and impulsiveness, researcher a number of human and animal studies which suggest a link between low levels of serotonin and aggression
Dopamine- has been identified as its linked to the dopaminergic pathway which results in pleasure, a rewarding feeling and desire to repeat a certain behavior
