Lesson 5 – Biological and
Psychological Explanations,
Trait Theory
Robert Wonser
Introduction to Criminology
Crime and Delinquency
1
Phrenology
• Skull’s size and shape
• Three types of behavior
and personality
• Intellectual
• Moral
• Lower (associated with
criminality)
2
Atavism
• Cesare Lombroso
• Italian doctor
• Linked criminality to atavism
• Evolutionary throwback
• Criminals are evolutionary
accidents
• Evidence was extensive
measurements of Italian prisoners
3
Lombroso’s Research
• Very popular theory
• Methodologically flawed
• Non-criminal inmates
• Lack of statistical power
• Refuted his own work by the end of his
career
• Goring’s research on English prisoners
4
Lombroso and Women
• First criminologist to include women in his
research
• Explanation of female criminality was
flawed
• Due to sexism of 19th century
• Women more likely to be atavists
5
Earnest Hooten’s Research
• Revived interest in
• Labeled criminals
physiological explanations
• “Organically inferior”
in 1939
• “Low-grade human
organisms”
• Measured 14,000 American
• Were biologically inferior
prisoners with a control
group of non-criminals
• Argued for sterilization of
criminals
• Criminals had
• Work suffered from
• Low foreheads
methodological issues
• Crooked noses
• Narrow jaws
• Small ears
6
• Long necks
William Sheldon’s Somatotypes
• Linked physique and crime
• Somatotypes: Body shape
effects criminality
• Endomorphs
• Heavy, short arms/legs,
extroverts
• Mesomorphs
• Athletic, muscular, aggressive
• Ectomorphs
• Thin, introverted
7
Delinquents tended to be
mesomorphic.
Research had similar
methodological issues as
Lombroso and Hooten
Development of Trait Theory
• Trait Theory - The view that criminality is
a product of abnormal biological or
psychological traits that are heritable.
• Trait theories can be subdivided into
two major categories:
• Those that stress biological makeup
• Those that stress psychological
functioning
8
Biological
Trait
Theories
9
Research on Biological Trait Theory:
Family, Heredity, and Genes
• Early research
• Richard Dugdale
• Studied New York Family (the Jukes)
• Followed family tree back 200 years
• Genetic or learned?
• 140 of 1,000 were criminals; problem? No
control group
• While many were criminals, Dugdale could
not definitively conclude it was due to
heredity
10
Twin Studies
• Identical twins
• Genetically equivalent
• Evaluated when twins are raised by biological
parents
• Research shows support for genetic
explanations of crime
• High concordance among identical twins;
problematic because they spend more time
together, tend to have same friends, more
attached to each other, etc.
11
Adoption Studies
• When twins raised by adopted
parents/guardians
• Results of these studies are mixed
12
Molecular Genetics
• Research examines link between genes
and crime
• Mutations in genes linked to high risk
behavior
• Young males with the mutation MAOA
were more likely to be violent, in
gangs, and arrested
13
Evolutionary Biology
• Since dawn of humans:
• Attempts to link evolution to specific
traits
• Example: rape
• However, rape rates vary widely from
culture to culture
14
Chromosomal Abnormalities
• X and Y chromosomes
• Determines who is male and female
• XYY chromosome
• Linked to 1/1000 men
• Tall, long arms, and low intelligence
• Linked to criminality
15
Brain Abnormalities
• Positron emission tomography (PET)
• Magnetic resonance imaging (MRI)
• Brain impairment linked to:
• Antisocial behavior
• Violence
16
Neurochemical Factors
• Hormones
• Testosterone
• Men commit more crime than females
• Mixed research
• PMS
• Emotional condition might be linked to
aggression
• Mixed research findings and controversial
17
Neurotransmitters
• Serotonin
• In animal studies, linked to higher
levels of aggression
• In human studies, linked to violent
criminality
18
Diet and Nutrition
• Older research
• Mixed on link between
diet/nutrition and crime
• Newer research
• Malnutrition in early
adolescence linked to
antisocial behavior and
criminality as teenagers
19
Miscellaneous Biological Links
• Pregnancy
• Maternal habits have link to child’s
future behavior
• Birth complications linked to future
child behavior
• Early puberty
• Leads to delinquency/antisocial
behavior
20
Evaluation of Biological
Research
• Many enthusiastic about recent
research in this area
• Sociologist still uneasy with biological
explanations
• Most advocate a blending of biological
and sociological theories/research
21
Psychological Explanations
• Psychoanalytic explanations
• Moral development
• Intelligence
• Link of race, IQ, and crime
22
Personality and Crime
• Rorschach tests
• Childhood temperament
• Impulsivity
• Irritability
• Hyperactivity
23
Evaluation of Psychological
Explanations
• Compliment sociological explanations
• Limited focus
• Use of small samples
• Disregard of structural factors
• Causal order remains unclear
24
Arousal Theory
• For a variety of genetic and
environmental reasons, some
people’s brains function
differently in response to
environmental stimuli and we
seek to maintain an optimal
level of stimulation.
25
Evaluation of Trait Theory
• Critics argue that some trait theories are
racist and faulty.
• Do trait theories suggest that people in
the South, Midwest, and inner cities are
more genetically inferior and
psychologically impaired?
• Contemporary trait theories argue that
some people have potential to be violent
or criminal and these traits may be
triggered environmentally.
26
Abnormality or Normality?
• Psychological approaches suggest
crime/criminals are psychologically
abnormal
• Studies show that violent criminals have far
higher levels of abnormal EEG recordings
than non-violent or one time offenders
• Can still commit crime and be
“psychologically normal”
• Milgram: Shock experiments
• Zimbardo: Mock prison experiments
27