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FORENSIC PSYCHOLOGY: BIOLOGICAL EXPLANATIONS - Coggle Diagram
FORENSIC PSYCHOLOGY: BIOLOGICAL EXPLANATIONS
ATAVISTIC FORM
1876 - Cesare Lombroso wrote
L'Huomo Delinquente
, in which he explained that criminals were "genetic throwbacks" - a less evolved sub-species of human. Since they were born, they had a natural tendency to commit crimes and their criminality was inevitable.
He examined the facial and cranial structures of over 4000 criminals (living and deceased) and identified a number of 'atavistic' characteristics that indicate criminals.
narrow, sloping brow; strong, prominent jaw; high cheekbones; facial asymmetry; dark skin; extra nipples/fingers/toes; insensitivity to pain; use of criminal slang; tattoos; unemployment.
He further specified features for distinct criminals, such as murderers (bloodshot eyes, curly hair, long ears), sexual deviants (glinting eyes, swollen, fleshy lips, projecting ears), and fraudsters (thin and ‘reedy’ lips).
He claimed that only 40% of the criminals that he studied had no atavistic characteristics. He was most influenced by performing an autopsy on Vilella, a criminal, and identified that he had a cerebral anomaly that is often found in lower apes, birds and rodents called the median occipital fossa, which likely led him to believe that criminals were less evolved.
GENETIC EXPLANATIONS
Offenders inherit a gene, or combination of genes, that predispose them to commit crime
TWIN STUDIES
Lange (1930) investigated 13 MZ and 17 DZ twins where one of the twins had served time in prison, and found that 10 of the MZ twins and only 2 DZ twins had a co-twin who was also in prison, leading to the conclusion that genes must play a predominant part in offending behaviour.
ADOPTION STUDIES
Crowe (1972) found that adopted children who had a biological parent with a criminal record had a 50% risk of having a criminal record by the age of 18, whereas adopted children whose mother didn't have a criminal record only had a 5% risk
CANDIDATE GENES
Tiihonen et al 2014, lead a genetic anlysis of almost 900 offenders revealed abnormalities on two genes that can be associated withviolent crime: the MAOA gene (controls dopamine and seratonin - aggressive behaviour); the CDH13 (linked to substance abuse and ADHD). Within the Finnish sample, individuals with both were 13 times more likely to have a history of violent behaviour, however this research is in its infancy and has not yet been replicated.
DIATHESIS-STRESS MODEL
A tendency towards criminal behaviour may come about through the combination of genetic predisposition and biological or psychological trigger, eg. being raised in a dysfunctional environment or having criminal role models.
NEURAL EXPLANATIONS
Evidence suggests there may be neural differences in the brains of criminals and non-criminals. Research focuses on people diagnosed with APD (antisocial personality disorder, formally psychopathy), which is associated with reduced emotional responses, a lack of empathy for the feelings of others, and characterises many convicted criminals.
PREFRONTAL CORTEX: Raine imaged the brains of people with APD and found that they have reduced activity in the prefrontal cortex, the part of the brain that regulates emotional behaviour. Raine et al (2000) also found that they had an 11% reduction in the volume of grey matter in the prefrontal cortex compared to controls.
MIRROR NEURONS: Keysers et al 2011, found that criminals with APD can experience empathy when asked to empathise with a person depicted on film experiencing pain, as their empathy reaction controlled by mirror neurons in the brain fired. People with APD are not entirely without empathy, and they may have a neural 'switch' that can be turned on and off, unlike in normal brains where this switch is permanently on.
EVALUATION
ATAVISTIC FORM
LARGE CONTRIBUTION TO CRIMINOLOGY: Lombroso has been hailed as the 'father of modern criminology' (Hollin 1989) and credited as shifting emphasis in research away from moralistic discourse to scientific discourse (i.e. weak-minded to evolution and genetics). Also, in trying to describe how particular types of people are likely to commit particular types of crime. Lombroso's theory heralded the beginning of criminal profiling. In this way, he made a major contribution to the science of criminology.
SCIENTIFIC RACISM: Many of the features that Lombroso identified as criminal and atavistic, such as curly hair and dark skink, are most likely to be found among people of African descent. Similarly, his description of the atavistic form being as 'uncivilised, primitive, savage' would lend support to the eugenic philosophies of the time that some cultural groups are 'genetically unfit' and needed to be eliminated. Lombroso's intention is unclear, but there is no doubt that these racial undertones are uncomfortable and a controversial legacy that overlays his work.
CONTRADICTORY EVIDENCE: Goring (1913) compared 3000 criminals to a control group of 3000 non-criminals and concluded that there was no evidence that offenders are a distinct group with unusual physical characteristics. However, he did suggest that many people who commit crimes have a lower-than-average IQ - this offers some limited support for the idea of a criminal sub-species. Moreover, this evidence does question the key element of his theory that criminals are different in terms of their appearance.
POOR CONTROL IN LOMBROSO'S RESEARCH: Unlike Goring, Lombroso did not compare his criminal sample with a non-criminal control group. Had he done so, the significant differences in atavistic form may have disappeared. Lombroso's research also failed to account for other important variables. Many of the criminals he studied had a history of psychological disorders which may have acted as confounding variables. Therefore, the evidence on which the atavistic form is based has serious flaws.
CAUSATION: Even if there are criminals who have atavistic elements in their facial appearance, this does not necessarily mean this is the cause of their offending. Facial and cranial differences may be influenced by other factors, eg. poverty or poor diet, rather than being an indication of delayed evolutionary development. Although, in fairness to Lombroso, in his later work he acknowledged that criminals could be made as well as born.
GENETIC AND NEURAL EXPLANATIONS
METHODOLOGICAL PROBLEMS WITH TWIN STUDIES: Lange's research was poorly controlled, eg. judgements of whether twin pairs were MZ or DZ were based on appearance rather than DNA testing. Also, most twins are reared in the same environment - so concordance rates may be due to shared learning experiences rather than genetics. Methodological issues such as confounding variables mean twin studies of criminality may lack validity.
SUPPORT FOR THE DIATHESIS-STRESS MODEL OF CRIME: Mednick et al. (1984) studied 13,000 Danish adoptees and criminality operationalised as having at least one court conviction which was checked against police records. When neither biological nor adoptive parents had convictions, the percentage of adoptees that had a conviction was 13.5%. This rose to 20% when either of the biological parents did, and 24.5% when both adoptive and biological parents did. These data suggest that both genetic inheritance and environment influence criminality - supporting the diathesis-stress model of crime.
METHODOLOGICAL PROBLEMS WITH ADOPTION STUDIES: Adoption studies are complicated by the fact that many children experience late adoption, so they spent time with their biological parents before adoption. In addition, lots of adoptees maintain contact with their biological parents. Both of these points make it difficult to assess the environmental (nurture and nature) impact the biological parents might have had.
BIOLOGICALLY REDUCTIONIST: Criminality is complex: explanations that reduce offending behaviour to a genetic or neural level ignore higher level explanations. Crime runs in families but so do poverty, deprivation, and mental illness. This makes it difficult to unblur the effects of genes and neural influences from other factors. This indicates that genetic and neural explanations in isolation are too simplistic.
BIOLOGICALLY DETERMINIST: The notion of a 'criminal gene' presents a dilemma. The legal system is based on the premises that criminals have personal and moral responsibility for their crimes. Only in extreme cases, eg. diagnosis of mental illness, can someone claim that they were not acting entirely of their own free will. This raises ethical questions about what society does with people who are suspected of carrying criminal genes and who therefore have a limited choice.