Biological Theory - Eysneck's theory of criminal behaviour

The theory

Eyesneck proposed that we have 3 personality traits. We’re all born with these traits but to varying degrees. This depends on genetic inheritance

3 personality traits

Extraversion

Neuroticism

Psychoticism

Extraversion

People who have high E scores:

* Outgoing
* Sociable
* Confident
* Prone to boredom

Opposite of extraversion

Introversion:

* Quiet
* Shy
* Unassertive

RAS

Reticular activation system

Function of the Reticular Activation System (RAS)

Controls/Receives incoming information and affects what you pay attention to and how aroused you are

How the CNS relates to extraversion in criminal personality

* Eyensneck believes extraversion is linked to arousal in CNS
* RAS is located in brain stem and restricts stimuli from environment, affecting how much cerebral cortex gets stimulated
* This means they seek risky behaviour to increase stimulation which in some cases, is illegal leading them to becoming criminals
* They have a stronger dopamine reward system meaning they respond positively to reinforcers like money/sex leading them to acquire it through illegal means

Autonomic nervous system (ANS)

Regulates the brain limbic system - a network in the brain controlling emotional expression such as violence

Neuroticism

People who have high N scores:

* Anxious
* Angry
* Prone to feeling guilty

Opposite of neuroticism:

Stability:

* Calm
* Even tempered
* Not easily stressed

How the ANS relate to criminals with neuroticism

* Eyesneck believes neuroticism is linked with over-arousal in the ANS.
* People who score highly in neuroticism are over aroused, meaning their limbic system will be over stimulated leading to violent behaviour

Sympathetic nervous system

a network of nerves that helps your body activate its “fight-or-flight” response

Examples of parts of body affected by the Sympathetic nervous system in a Neurotic person

* Reduced saliva flow (body shut down non essential functions)
* Increased Heart rate
* Vasoconstriction (Narrowing of blood vessels by small muscles in their walls)
* Glycogen → Glucose

Psychoticism

People who have High P scores are:

* Impulsive
* Aggressive
* Selfish

Opposite of psychoticism

High impulsive control:

* Warm
* Considerate
* Conscientious

How the brain affects people who are psychotic

* This behaviour is a result of excess dopamine neurons causing an overproduction of dopamine in nervous system
* This leads to more aggressive/impulsive/selfish behaviour

Theory is deterministic (Criticism)

* Believes people who’ve criminal biology will become criminals
* Ignores freewill and that people make own choices about committing crimes.
* Stops accountability for actions if they blame biology for their behaviour

Ignores individual differences (Criticism)

* People have varied reasons for turning to crime so it’s wrong to assume all neurotics extroverts have similar reasons for crime
* Argued it’s wrong to lump people together and ignore individual difference

Behaviour is result of nature/nurture interacting

* Nurture is considered but is not enough evidence
* With the right environment, people don’t need to be criminals
* Focusing on role of nurture can try and stop people with neurotic extraversion from breaking rules