AC2.1 - Biological theories of criminality Flashcards
What are physiological theories of criminality?
Theories that look at the physical form as a cause of criminality
Who was Cesare Lombroso?
An Italian criminologist in the 1800s who measured the features of thousands of Italian prisoners, believing that criminality was linked to physical form
Explain the atavistic theory of offending (1876)
Lombroso believed that criminals were a link to a less evolved version of humanity, and could be identified by features such as protruding ears, thick lips, coarse hair, flat noses and a reduced pain sensitivity
What are the strengths of the atavism theory?
- Lombroso linked criminality to biology, when it had always been seen as a religious issue.
- He highlighted the importance of examining medical records.
- First to suggest offending was not always a choice.
What are the weaknesses of the atavism theory?
- Deterministic
- Creates harmful stereotypes
- Biased towards people of black backgrounds and people with learning disabilities
- Didn’t compare criminals to a control group
- Mostly studied men, not generalisable
- Outdated and not supported by modern research
Explain Sheldon’s somatotype theory (1940s)
Sheldon believed that people with certain body types were at a higher risk of offending
Define mesomorph, ectomorph and endomorph
- Mesomorph = hard, musculare body, adventuorous, risk taking
- Ectomorph = soft, round body, sociable
- Endomorph = thin, fragile body, shy and self conscious
Why did Sheldon believe mesomorphs were more likely to offend?
He studied 200 delinquents and compared them to 200 non-delinquent college students, finding that the delinquents had mesomorph bodies and the students had ectomorph bodies. Sheldon believed mesomorphs were attracted to offending due to their musculature, assertiveness and risk-taking personality.
Strengths of somatotype theory
- Sheldon compared his deliqnuents to a control group
- Longitudinal study over 10 years
- Glueck and Glueck 1956 support Sheldon’s research
- The finding of his study did support the somatotype theory
Weaknesses of somatotype theory
- Deterministic and creates harmful stereotype
- Not all crimes require mesomorphs e.g. cyberfraud
- Doesn’t account for how body type can change and for criminals who aren’t mesomorphs
What are genetic theories of criminality?
Theories that look at how hereditary and inhereted characteristics could lead to criminal behaviour
What are twin studies?
Studies that look at the concordance rate of criminal behaviour in monozygotic (identical) and dizygotic (non-identical) twins
Summarise Lange’s 1929 twin study
In the sample he studied, he found that 10/13 MZ twin pairs had both served time in prison, and 2/17 for DZ twins
Summarise Christiansen’s 1977 twin study
Studied 3586 twin pairs in Denmark. Found that if 1 MZ twin had a criminal conviction, there was a 52% the other would too. 22% with DZ twins.
Strengths of twin studies
- Logical to study MZ twins because they’re genetically identical
- Provides some support to the idea that criminal behaviour has a genetic element
Weaknesses of twin studies
- There would need to be a 100% concordance rate to prove that criminality is genetic, whereas studies show only about 50% in MZ twins
- Similar behaviour could be related to environment rather than genes
What do adoption studies look at?
How adopted children behave compared to their adopted and biological parents, to see whether genes or environment have more influence on behaviour
Summarise Mednick’s 1924 - 47 study
Examined data on 14,000 adopted sons in Denmark. Found that 20% had criminal records if their bio paretns did, 14.7% if adoptive parents did
Summarise Hutchings and Mednick’s 1975 study
Compared adoptees with and without criminal records. Found that more had biological parents who also had criminal records compared with adoptees who weren’t criminal
Strengths of adoption studies
- Easier to seperate biological and environmental influences
- Studies show correlation between the behaviour of adoptees and their biological parents
Weaknesses of adoption studies
- Don’t provide strong evidence that criminality is genetic.
- Adopted children often placed in similar environments to those in which they were born
- Not all children are adopted straight after birth, so environment could’ve already had an influence
What is 47 XYY syndrome (Jacob’s syndrome)
When a male has an extra Y chromosome. This is believed to cause symptoms like being unusually tall, acne, learning disabilities and increased aggression
Studies that back up 47 XYY theory
Price and Whatmore 1967 - found XYY males were more likely to be immature and aggressive
Jacob (et al) 1965 - found an link between XYY chromosomes and violent crime
Weaknesses of XYY syndrome
- Deterministic and not a proven cause of violence as it’s rare
- Studies often done on prisoners of psychiatric patients which don’t represent the population
- XYY males fit criminal stereotypes
