r Biological theories of criminalityBiological theories of criminality

hav

ior Biological theories of criminalityBiological theories of criminality

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Crime is the result of chemical states, physiological

Cri

min Crime is the result of chemical states, physiological

conditions and biological predispositions

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Biological theories of criminalityBiological theories of criminalityr

Biocriminology

Genetics

hav

ior Genetics

Stress

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hC

rim

inC

Biological theories of criminalityBiological theories of criminalityr

Biocriminology

Biochemistry

hav

ior Biochemistry

Prefrontal lobe dysfunction

Bi h li i

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h Birth complications

Genetics

Cri

min Stress

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Biochemistry risk factorsBiochemistry risk factorsr

Serotonin – low levels of serotonin seem to increase violence

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ior

Serotonin is a product of tryptophan

Th b t f t t h ?

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h The best source of tryptophan?

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min

C

Tryptophan at ThanksgivingTryptophan at Thanksgivingr

So if everyone has turkey at Thanksgiving, why is there no decrease in violence at this time?

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ior

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Biological

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Individual

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PsychologicaStructural

Nutrition and blood sugarNutrition and blood sugarr

Hypoglycemia

Body’s inability to process sugar effectively resulting in

hav

ior Body s inability to process sugar effectively, resulting in

low blood sugar

Mental confusion, emotional instability, neurotic or

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h , y,psychotic behavior

Excessive alcohol intake

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min

Binge-drinkers tend to neglect nutrition, leading to irritability, heightened risk of conflict and violence, and

h l iC … hypoglycemia

UnderarousalUnderarousalr

Researchers have found that males who engage in violent and non-violent crime tend to have

hav

ior

Lower resting heart rates

Reduced skin conductivity

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l Be

h Reduced skin conductivity

Slower EEG activity

All i k f t f ti i l b h i

Cri

min All risk factors for anti-social behavior

Underarousal claimed to be a neurological d f ti l di l t it i f C dysfunction leading people to commit crime for the thrill of it

A l i l d b h f l l bArousal is regulated by the frontal lobe…

Biological theories of criminalityBiological theories of criminalityr

Biocriminology

Biochemistry

hav

ior Biochemistry

Prefrontal lobe dysfunction

Bi h li i

na

l Be

h Birth complications

Genetics

Cri

min Stress

C

Frontal lobesFrontal lobesr

Control impulse control, judgment, language

hav

ior production, working

memory, motor function, problem solving sexual

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h problem solving, sexual behavior, socialization, and spontaneity.

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min

Assist in planning, coordinating, controlling, C and executing behavior.

Timothy McVeighTimothy McVeighr

Gulf War veteran

Perpetrator of the Oklahoma City

hav

ior Perpetrator of the Oklahoma City

bombing• April 19 1995 Alfred P Murrah Federal

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h • April 19, 1995, Alfred P. Murrah Federal Building

• 168 lives and over 800 injured

Cri

min Motive?

• Claimed anti-government sympathies b f W d R b RidC because of Waco and Ruby Ridge

Timothy McVeighTimothy McVeighr

According to Michel and Herbeck, McVeigh suffered three head injuries

hav

ior during his youth

Did this cause neuropsychological

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h p y gtrauma?

Many death row inmates have

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min

yneuropsychological problems

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Frontal lobesFrontal lobesr

Extremely vulnerable area

Injuries/lesions here cause significant

hav

ior Injuries/lesions here cause significant

problems

Affects Impulsivity and personality

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l Be

h Affects Impulsivity and personality

Inability to plan and execute complex sequences of actions

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min

s qu c s o act o s

Inability to reason

Inappropriate sexual behaviorC Inappropriate sexual behavior

Inability to modify behavior to social norms

Frontal lobe damageFrontal lobe damager

What can enhance or diminish an injured person’s predisposition to violence?

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ior

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Biological

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Individual

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PsychologicaStructural

Birth complicationsBirth complicationsr

Birth complications may lead to brain dysfunction

Can lead to cognitive deficiencies and then to school

hav

ior Can lead to cognitive deficiencies and then to school

failure and loss of self-control

Risk increases in combination with early maternal

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h Risk increases in combination with early maternal rejection

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min

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Biocriminology – what to do about itBiocriminology – what to do about itr

Good evidence that social variables and adjusting to conditions can mitigate violent tendencies

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ior

Prenatal intervention for vulnerable mothers

Education strategies to minimize maternal rejection

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h Education strategies to minimize maternal rejection

School curriculum tailored to high risk students

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min

Biological

C

Individual

PsychologicalStructural

Biological theories of criminalityBiological theories of criminalityr

Biocriminology

Genetics

hav

ior Genetics

Phrenology

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h

Lombroso

Heredity

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min Biosocial theories

StressC

A brief history of geneticsA brief history of geneticsr

Gregor Mendel (1886)

Used Darwin’s Theory of Natural Selection to study

hav

ior Used Darwin s Theory of Natural Selection to study

the inheritance patterns of physical traits in pea plants.

Results ignored or disparaged

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h g p g

Revival in the 1900s

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min Revival in the 1900s

Refocus on hereditabilityof traitsC of traits

A brief history of geneticsA brief history of geneticsr

1940s-1970s: Focus on DNA

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ior

DNA identified as genetic material

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h

Double helix structure identified

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min

1970s-Current: GC Genomics

Study unique sequence of genes

What is genetics?What is genetics?r

The science of heredity and variation

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ior

Passage of traits between generations

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h g

Deoxyribonucleic Acid (DNA)

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min

( )

24 chromosomes in humans

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PhrenologyPhrenologyr

Phrenology is a theory which claims to be able to determine character, personality traits and

hav

ior criminality on the basis of the shape of the head

Developed by German physician Franz Joseph

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h p y p y J pGall around 1800, the discipline was popular in the 19th century

Cri

min Most prominent 21st century adherent?

Stephen Colbert!C p

Early trait theoriesEarly trait theoriesr

Cesare Lombroso (1835-1909)

‘The born criminal’

hav

ior The born criminal

Theory of criminal atavism

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h

Large of forward projecting jaws

Low sloping forehead

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min

High cheekbones, flattened or upturned nose

Handle-shaped ears, hawk-like noses or fleshy lipsC p , y p

Shifty eyes, scanty beard or baldness

Insensitivity to pain long armsInsensitivity to pain, long arms

Human Genome ProjectHuman Genome Projectr

Project designed to sequence the 3 Billion chemical base pairs in human DNA

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ior

Completed in 2003 at the cost of $3 Billion

Data Used in medicine agriculture biology etc

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h Data Used in medicine, agriculture, biology, etc

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Somatotype approachSomatotype approachr

Classification of human physical types developed by psychologist W.H. Sheldon.

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ior

Sheldon studied the photographed bodies of some 4,000 Ivy League students from front view,

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h y gside view, and back view.

People can be classified as to body build in terms

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min

p yof three fundamental body types (the somatotypes):

C

Endomorphic: round / fat

Mesomorphic: muscular

Ectomorphic: slim / linear

SomatotypesSomatotypesr

Mesomorphic claimed to often engage in

hav

ior assertive gesturing,

which can lead to aggressive behavior

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h aggressive behavior

Some studies have found a link between

Cri

min found a link between

mesomorphic body types and delinquencyC

What are some potential problems Endomorphic, Mesomorphic, Ectomorphic p pwith this research?

HeredityHeredityr

Charles Goring, English physician

In 1913 published a comparison of

hav

ior In 1913 published a comparison of

3,000 English convicts with 3,000 people, including military personnel from the British Royal Engineers

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h from the British Royal Engineers

Found no real difference, though criminals tended

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min

gto be smaller in stature. Given that size and mental ability are inherited, generalized that criminals were still born with inherited traits C criminals were still born with inherited traits.

While disproving Lombroso, Goring’s research still had some problems Such as ?still had some problems. Such as…?

Are we born criminals?Are we born criminals?r

The central problem with genetic traits…

Genetic theory suggests that your individual

hav

ior Genetic theory suggests that your individual

chromosomal characteristics are inherited from your parents genes at conception

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l Be

h y p g p

However, as we develop as a fetus other traits are created from genetic mutations

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min

g

The resulting characteristics are biological, but not inheritedC

Biosocial theoriesBiosocial theoriesr

Some of the most modern thinking in this area in in the relationship between an individual’s

hav

ior biochemistry and the environment

Expose to certain minerals appears to promote

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l Be

h p pp paggressive behavior. Which ones?

Mg - Cu - Cd - Zn - Pb

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min

g

C

Male hormonesMale hormonesr

Increased secretion of hormones in adolescent males linked to anti-social behavior

hav

ior

The biggest culprit?

Testosterone

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l Be

h Testosterone

So does more testosterone lead to more aggressive behavior?

Cri

min

aggressive behavior?

It appears that the reverse is true

Or even that testosterone has a distal effectC Or even that testosterone has a distal effect

• Increased testosterone social inhibitions delinquency

XYY chromosomesXYY chromosomesr

Lombroso’s view that criminal tendencies were inherited fell out of favor until the 1970s

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ior

Discovery of the XYY chromosome in some males (1 in 1,000)

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h ( )

XYY boys have increased risk of learning difficulties (in up to 50%) and delayed speech

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min

( p ) y pand language skills (what is distal, what is proximate?)

Those with XYY more likely to have an arrest C yrecord, but not more likely to be for violence

XYY not inherited; random mutationXYY not inherited; random mutation

Twin studiesTwin studiesr

Further evidence of a genetic propensity toward involvement in crime comes from studies

hav

ior examining twins or non-twin siblings who have

been adopted out into different families at or soon after birth

na

l Be

h soon after birth.

Dizygotic (product of t t )

Cri

min two separate eggs)

Monozygotic (twins the product of one egg –C product of one eggshare the same DNA)

Truth in genetic propensity?Truth in genetic propensity?r

Twin studies generally find that both members of a monozygotic (i.e. identical) twin pair are more lik l b i l d i i h b h b

hav

ior likely to be involved in crime than both members

of a dizygotic (i.e. fraternal) twin pair.

f

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h

Munich physiologist Johannes Lange found

When a non-twin sibling was imprisoned, so was the ibli l 8% f th ti

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min sibling only 8% of the time

When a dizygotic twin was imprisoned, so was the twin 12% of the timeC twin 12% of the time

When a monozygotic twin was imprisoned, so was the twin 77% of the time

Some cautionSome cautionr

The results of several adoption studies have shown that there is greater similarity in the

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ior criminal histories of sons and their natural fathers

than between sons and their adoptive fathers.

na

l Be

h

But…Most of the evidence from twins studies suggests that any effects of heredity are evidence in people who commit less serious crimes

Cri

min in people who commit less serious crimes.

The interaction between children and their adopted parents may itself increase the risk of C adopted parents may itself increase the risk of later involvement in crime. Therefore the environment may play a part.y p y p

So in summary?So in summary?r

While there is some statistical evidence

hav

ior statistical evidence

consistent with the possibility that there

b h d

na

l Be

h may be inherited factors in crime, that evidence is also open

Cri

min evidence is also open

to interpretation in ways which do not i li i C implicate genetic factors

Biological theories of criminalityBiological theories of criminalityr

Biocriminology

Genetics

hav

ior Genetics

Stress

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hC

rim

inC

Diathesis-stress modelDiathesis-stress modelr

A psychological theory that explains behavior as both a result of biological / genetic factors and life

hav

ior experiences

Diathesis

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h

An elegant term for a predisposition or tendency

A pre-existing vulnerability to certain stresses

Cri

min A pre existing vulnerability to certain stresses

Used to explain the onset of mental conditions such as schizophrenia or bipolar disorderC such as schizophrenia or bipolar disorder

Stressors and crimeStressors and crimer

Potential explanations for later criminality include

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ior

Childhood neglect and abuse

Alcohol vulnerability

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l Be

h Alcohol vulnerability

But stressors can be accumulative

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min

accumulative

Divorce, death of a parent, unemploymentC p y

Stress and crimeStress and crimer

However, some things can mediate stress…

hav

ior

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h

Biological

Cri

min Individual

C

PsychologicaStructural

r Biological theories of criminalityBiological theories of criminality

hav

ior Biological theories of criminalityBiological theories of criminality

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hC

rim

inC

MAOA deficiencyMAOA deficiencyr

Monoamine Oxidase A deficiency

Inherited genetic abnormality that alters levels of

hav

ior Inherited genetic abnormality that alters levels of

specific brain chemicals

Ch t i d b b d li t l t d ti

na

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h Characterized by borderline mental retardation and aggressive behavior

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min

C

What role should genetics play?What role should genetics play?r

Stephen Anthony Mobley

Accused of murder during the

hav

ior Accused of murder during the

commission of a robbery

Attempted to use family history and

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h p y ygenetics as a mitigating defense to avoid the death penalty

B li d h MAOA d fi i

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min Believed he was MAOA deficient

Executed March 2005

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Discussion questionsDiscussion questionsr

How much should genetic propensity be a factor in deciding prison sentence length?

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ior

How much should stress be used as an excuse for criminal behavior?

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Should people with a propensity for criminality be required to receive treatment?

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q

Should someone shown to be a potential future danger receive a longer jail sentence?C g g j