Biological theories

What are biological theories

•physiological

•genetic

•brain injuries and disorders

•biochemical explanations

What does physiological theories entail

Focusing on criminals physical characteristics

What do genetic theories entail

Focusing on the fact that criminality is inherited

What do brain injuries and disorders entail

Focusing on how damage to the brain can cause criminality

What do biochemical explanations theories entail

Focusing on the factors that change personality causing criminality such as hormones or substances

What are the 2 physiological studies

•Lombroso’s ‘born criminal’ theories

•Sheldon’s ‘somotypes theory’

What are the 3 genetic studies

•XXY theories

•adoption studies

•Twin studies

What do biochemical explanation studies

•sex hormones

•blood sugar levels

•drug and alcohol abuse

•other substances

What is a physiological theory

Focusing on physical characteristics of a criminal differs to the physical characteristics of a non-criminal

What is Lombroso’s ‘born criminals’ theory

1876- Lombroso argued that criminals were physically different to non-criminals. Criminals could be identified by their distinctive physical features.

What were some distinctive features Lombroso took interest in

•enormous jaws

•high cheek bones

•prominent eyebrow arches

Why did Lombroso believe features determined criminality

His theory corresponds to a primitive stage of evolution/ pre-social where they are unable to control impulses and have a high pain tolerance. He seen criminals as savages or apes in a normal society they are abnormal

What is Sheldon’s somatotype theory

Sheldon saw criminals as physically different to non-criminals- in his view, certain body types are likely to be linked to criminality

What are the 3 somatotypes

•endomorph

•ectomorph

•mesomorph

What are endomorphs

Soft and round lacking muscle and tone outgoing, sociable and relaxed

What are ectomorphs

Thin and fragile lacking fat and muscle- shy, self-conscious, emotionally restrained and thoughtful

What are mesomorphs

Muscular and strong- sensation seeking, adventurous, enjoy physical activity

What is a genetic theory

Focusing on the idea that crime is inborn, passed down from a parent- blood relation

What is a twin study

Monozygotic (identical) share the exact same genes as they are developed from the exact same egg. Therefore if one twin is criminal, the other twin ought to be criminal too

What is evidence of a twin study

Christiansen- found 52% concordance rate between MZ twins- where one twin had a conviction there was 52% of the other conviction

What did Christiansen find on dizygotic twins

Christiansen- but amount DZ twins there was only 22% chance f concordance rate for both twins to have a conviction

What are monozygotic twins

Identical

What are dizygotic

What is concordance

A statistical measure that describes the proportion of pairs of individuals that share an attribute, given that one already possesses this trait

What is an adoptive study

Adoption studies focus on testing for a genetic cause by comparing adopted children both to their biological and adoptive parents (adoptive- environment/biological-genetically inherited)

What is the difference in concordance rates between biological and adoptive parents

Biological-20% concordance

Adoptive-14.7% concordance

What is the XYY theory

An abnormality with the sex chromosome as the cause of criminality due to an extra Y chromosome- labelled the ‘super male syndrome’ leading to low intelligence/aggressive and violent behaviour

How do brain injuries connote to criminality

Certain injuries/ diseases and malfunctions to the brain have been linked to a chase of criminality

What is evidence on brain injuries

Some studies have proved that prisoners are more likely to have suffered brain damage than non-criminals (Phineas Gage/ Fred West)

How is disease linked to criminality with children

In 1920 children with encephalitis lethargy were linked to abnormal sexual behaviour, arson and destructiveness

How is disease linked to criminality in adults

Dementia, Huntington’s disease or brain tumours have been linked to criminal/ deviant or anti-social behaviour

What is the device that shows evidence of brain injuries

Abnormal brainwave activity is measured by an electroencephalograph (EEG). Some studies showing abnormal EEG readings amount ‘clearly insane’ murderers and psychotic criminals

What are biochemical explanations

Biochemical substances and processes as a cause of crime, because of their effect on the brain chemistry and mental processes. Like sex hormones/blood sugar levels and substance abuse

How do sex hormones for men create crime

Sex hormones on males either overproduction or underproduction of hormones can cause emoitional disturbances leading to crime - testosterone links to murder/ aggression and rape

How do sec hormones for women create crime

Pre-menstrual tension, post-natal depression and lactation leads to partial defences for women charged with crime ranging from shoplifting to infanticide as hormones affect mood and self-control

How can blood sugar levels cause crime

Hypoglycaemia can trigger aggressive reactions. Mainly linked to alcohol abuse

What is substance abuse

The intake of drugs and other substances-some legal while some are illegal

How does alcoholism link to crime

About 1000 arrests per day 80% of family violence cases link to alcohol

What does cocaine and crack do

Cocaine and crack links to violence

What can reduce aggression

Cannabis/ heroin and MDMA can reduce aggression

What can other substances do towards crime

Other substances ingested are linked to anti-social/ criminal behaviour such as food addictions, diet allergens, vitamin deficiencies and lead pollution. Affecting various biochemical processes in the body

What does lead and synthetic food colouring lead to

Lead and synthetic food colouring lead to hyperactivity

What does a vitamin B deficiency lead to

Vitamin B deficiency leads to erratic and aggressive behaviour