CRIMINAL PSYCHOLOGY
MODULE 2 : ORIGINS OF CRIMINAL BEHAVIOUR
Biological risk factors
Biological risk factors in criminal psychology refer to biological or physical conditions that
may increase a person’s likelihood of engaging in antisocial or criminal behaviour. These
factors do not directly cause crime, but they can make an individual more vulnerable,
especially when combined with psychological and environmental influences.
Behaviour Genetics
Behaviour genetics refers to the study of how genetic factors influence behaviour,
including tendencies related to aggression, impulsivity, and antisocial behaviour. In
criminal psychology, it explains how inherited traits may increase a person’s
vulnerability to criminal behaviour.
Some individuals may be born with genetic traits that affect:
Emotional regulation
Impulse control
Aggression levels
A commonly discussed gene is the MAOA gene (Monoamine Oxidase A). Variations
in this gene are associated with poor control over aggression, especially when the
individual has experienced childhood abuse or neglect.
(The MAOA gene (Monoamine Oxidase A) provides instructions for an enzyme that
breaks down neurotransmitters like serotonin, dopamine, and norepinephrine,
influencing mood, stress response, and brain development.)
Example
Imagine two children, A and B.
Both children have a genetic tendency for high emotional reactivity (linked to the
MAOA gene).
Child A grows up in a loving, supportive family with guidance and discipline.
Child B grows up in an abusive and neglectful environment.
👉 Outcome:
Child A learns to control anger and does not show violent behaviour.
Child B struggles with impulse control, becomes aggressive, and may engage in
antisocial or criminal behaviour during adolescence.
“Just like plastic doesn’t start a fire but worsens it, the MAOA gene doesn’t cause
crime but can amplify reactions when stress or trauma is present.”
, Pre- and Post-natal Malnutrition
Meaning:
Pre- and post-natal malnutrition refers to poor nutrition during pregnancy
(prenatal) and early childhood after birth (postnatal). This period is crucial for
brain development.
How it affects behaviour?🧠
The brain needs proteins, vitamins, iron, iodine, and fatty acids to develop normally.
Lack of proper nutrition can lead to:
Poor development of the prefrontal cortex (controls judgment, impulse control,
decision-making)
Reduced attention, learning difficulties
Poor emotional regulation
Increased impulsivity and aggression
Prenatal malnutrition (before birth)
If a mother is malnourished during pregnancy:
The fetus may have underdeveloped brain structures
Neurotransmitter systems may not mature properly
This can later show as:
Low self-control
Poor stress handling
Behavioural problems in adolescence
Example:
A child whose mother had severe nutritional deficiency during pregnancy may grow up with
poor impulse control and difficulty following rules.
MODULE 2 : ORIGINS OF CRIMINAL BEHAVIOUR
Biological risk factors
Biological risk factors in criminal psychology refer to biological or physical conditions that
may increase a person’s likelihood of engaging in antisocial or criminal behaviour. These
factors do not directly cause crime, but they can make an individual more vulnerable,
especially when combined with psychological and environmental influences.
Behaviour Genetics
Behaviour genetics refers to the study of how genetic factors influence behaviour,
including tendencies related to aggression, impulsivity, and antisocial behaviour. In
criminal psychology, it explains how inherited traits may increase a person’s
vulnerability to criminal behaviour.
Some individuals may be born with genetic traits that affect:
Emotional regulation
Impulse control
Aggression levels
A commonly discussed gene is the MAOA gene (Monoamine Oxidase A). Variations
in this gene are associated with poor control over aggression, especially when the
individual has experienced childhood abuse or neglect.
(The MAOA gene (Monoamine Oxidase A) provides instructions for an enzyme that
breaks down neurotransmitters like serotonin, dopamine, and norepinephrine,
influencing mood, stress response, and brain development.)
Example
Imagine two children, A and B.
Both children have a genetic tendency for high emotional reactivity (linked to the
MAOA gene).
Child A grows up in a loving, supportive family with guidance and discipline.
Child B grows up in an abusive and neglectful environment.
👉 Outcome:
Child A learns to control anger and does not show violent behaviour.
Child B struggles with impulse control, becomes aggressive, and may engage in
antisocial or criminal behaviour during adolescence.
“Just like plastic doesn’t start a fire but worsens it, the MAOA gene doesn’t cause
crime but can amplify reactions when stress or trauma is present.”
, Pre- and Post-natal Malnutrition
Meaning:
Pre- and post-natal malnutrition refers to poor nutrition during pregnancy
(prenatal) and early childhood after birth (postnatal). This period is crucial for
brain development.
How it affects behaviour?🧠
The brain needs proteins, vitamins, iron, iodine, and fatty acids to develop normally.
Lack of proper nutrition can lead to:
Poor development of the prefrontal cortex (controls judgment, impulse control,
decision-making)
Reduced attention, learning difficulties
Poor emotional regulation
Increased impulsivity and aggression
Prenatal malnutrition (before birth)
If a mother is malnourished during pregnancy:
The fetus may have underdeveloped brain structures
Neurotransmitter systems may not mature properly
This can later show as:
Low self-control
Poor stress handling
Behavioural problems in adolescence
Example:
A child whose mother had severe nutritional deficiency during pregnancy may grow up with
poor impulse control and difficulty following rules.
