Transcript Serial Killers

Serial Killers
Serial Killers are a study in the psychopathic
perversion - usually a man with a sexual dysfunction
The US has 5% of the world’s population
and 75% of its serial killers
• Buffalo Bill is the serial killer in The Silence
of the Lambs
• Dr. Lecter says that Buffalo Bill was not
born, but made through years of child abuse
• Buffalo Bill dresses like a woman, wears
makeup, hides his penis = gay lifestyles?
• Film perpetuates the idea that if you are gay
and a man you really want to be a woman
• Film links homosexuality, transsexuals, and
female impersonation directly to killing
Serial murder Films USA
Decade
1920s
1930s
1940s
1950s
1960s
1970s
1980s
1990s
No. of films
2
3
3
4
12
20
23
64
2
Serial murder Films USA
70
1920s
60
1930s
50
1940s
40
1950s
30
1960s
1970s
20
1980s
10
1990s
0
No. US Films
General Serial Killer Profile
Demographics
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Male (88.3%)
White
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Average intelligence
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80% of all serial killers
73% of male serial killers
93% of female serial killers
107 in our data base
n = 71
Often a police groupie
Seldom involved with groups
General Serial Killer Profile
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Demographics – Average age is 28
Males
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27.5 is average age at first kill
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Jesse Pomeroy (Boston in the 1870s)
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9 is the youngest (Clarence Hill)
72 is the oldest (Ray Copeland)
Killed 28 people by the age of 14
Spent 58 years in solitary confinement until he died
Females (Kelleher & Kelleher, 1998)
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30 is average age at first kill
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14 is youngest (Caril Ann Fugate)
55 is oldest (Marie Becker)
Angels of death, revenge killers, and team killers
tend to be younger
General Serial Killer Profile
Race
Race
Percentage
White
80.1%
Black
13.0%
Hispanic
4.5%
Asian
2.4%
General Serial Killer Profile
Childhood
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Unstable home (37%)
Absence of loving and nurturing relationship
Physical ailments and disabilities
Head injuries
Triad
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bed wetting
fire starting
animal torture
Effects of the Family
Child Abuse
Comparison of Serial Killers to the General Population
(Mitchell & Aamodt, 2004)
Type of Abuse
General
Population
Serial Killers
Physical
6%
36%
Sexual
3%
26%
Psychological
2%
50%
Neglect
18%
18%
Other
6%
Not applicable
No Abuse Reported
70%
32%
General Serial Killer Profile
Forensic History
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Triad
Most have a criminal history (80%)
75% spent time in jail/prison prior to their
serial killing
Many received psychiatric treatment
33% spent time in a forensic unit
Many murdered well before their serial
killing
Most frequently selected victims
[Hickey (2002; 399 serial killers)]
Strangers (70%)
1. College students,
prostitutes
2. Little boys and girls
3. Hitchhikers
4. People at home
5. Handicapped people
6. Store-owners,
landlords
7. People walking street
8. Older women
9. Police officers
10. Derelicts/transients
11. People responding to
newspaper ads
Acquaintances (20%)
1. Friends and neighbours
2. Girlfriends and
boyfriends
3. Waitresses and
prostitutes
4. Co-workers
5. Landlords, employers,
guards
6. Gang members
7. Patients
Family (10%)
1. Own children
2. Husbands
3. Wives
4. In-laws
5. Nephews, nieces
6. Own mother
7. Sibling
8. Grandparents
Male Serial Killers(399):
Methods
 1. Firearms mainly (41%)
 2. Suffocation (37%)
 3. Stabbing (34%)
 4. Bludgeoning (26%)
 5. Firearms only (19%)
 6. Poison (11%)
 7. Drowning (3%)
 8. Other (2%)
Motives
 1. Sex (55%)
 2. Control (29%)
 3. Money (19%)
 4. Enjoyment (16%)
 5. Racism and hatred (11%)
 6. Mental problems (6%)
 7. Cult-inspired (5%)
 8. Attention (2%)
Female Serial Killers (62):
Methods
 1. Poison (80%)
 2. Shooting (20%)
 3. Bludgeoning (16%)
 4. Suffocation (16%)
 5. Stabbing (11%)
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6. Drowning (5%)
Motives
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1. Money (74%)
2. Control (13%)
3. Enjoyment (11%)
4. Sex (10%)
5. Drugs, cult involvement,
cover up, or feelings of
inadequacy (24%)
III. Female Serial Killers & their victims
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Female serial killers tend to be
"black widows" who kill a
succession of husbands, lovers, or
other family members.
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They can also be nurses or other
medical professionals who become
self-appointed "angels of death"
murdering babies, elderly, or the
desperately ill in a misguided
effort to relieve their suffering.
Aggression Statistics
15,533 murders in the U.S. in 1999
 15,586 murders in the U.S. in 2000
 16,037 murders in the U.S. in 2001
 16,204 murders in the U.S. in 2002
 Expand definition to violent crime
(murder, non-negligent manslaughter,
rape, robbery, and aggravated assault):
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1,430,693 in 1999
 1,425,486 in 2000
 1,439,480 in 2001
 1,426,325 in 2002
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What did Freud say?
Eros: Life force
 Drive-thwarted
 Instinct
 Catharsis
 Thantos: death force
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What did Freud say?
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"The existence of this inclination to aggression,
which we can detect in ourselves and justly
assume to be present in others, is the factor
which disturbs our relations with our neighbors
and which forces civilization into such high
expenditure [of energy]. In consequence of this
primary mutual hostility of human beings,
civilized society is perpetually threatened with
disintegration.
What did Freud say?

Civilization has to use its utmost efforts in
order to set limits to man's aggressive
instincts and to hold the manifestations of
them in check by psychical reactionformations. Hence, therefore, the use of
methods intended to incite people into
identifications and aim-inhibited relations of
love, hence the restrictions upon sexual life,
and hence too the ideal's commandment to
love one's neighbor as oneself-a
commandment which is really justified by the
fact that nothing else runs so strongly counter
to the original nature of man."
Is Aggression Instinctual?
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Hobbes, Freud, and Lorenz say yes.
Freud and Lorenz in particular believe that aggressive
energy builds up and must be released.
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Catharsis theory.
Unfortunately, aggressive catharsis frequently leads to more
aggression.
One problem with instinctual explanations is that they
tend to be descriptive and circular.
Theories of Aggression
Instinct Theory: Through evolution, humans
have inherited a fighting instinct similar to that
found in many species of animals.
Leading Proponent: Konrad Lorenz (ethology)
He says we have a biological need for
aggression. It gets stronger as time passes
since the last aggressive act (like hunger
increases hours after a meal).
This causes our energy level (drive level) to
increase. This energy must somehow be
released (“catharsis”).
Theories of Aggression
Instinct Theory says that humans learn their
own individual ways of expressing aggressive
motivation. Nonhuman species behave in ways
that are genetically programmed and
characteristic of all members of the species.
Fixed Action Pattern: complex behavior
that is largely unlearned and found in all
members of a species (or subgroup), and
that is triggered by a very simple stimulus
in the environment (“releaser”).
Hydraulic Theory predicts:
1. Aggression is inevitable - the
accumulating energy must find an outlet
 2. Humans & animals will actively 'look
for fights'.
 3. After an attack an animal / human will
become less aggressive.
 4. Animals reared in isolation will show
aggressive behaviour.
Roots of Violence
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Instinct- innate (unlearned) behavior pattern
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Freud- redirecting the “death instinct” (thanatos) to
others
Lorenz- inherited “fighting instinct” developed through
the course of evolution (strongest survive)
Not supported because:
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Human aggression takes many forms
Frequency of violence varies across cultures
Engaging in potentially lethal behavior makes little
sense in evolutionary terms
If not instinctual, can aggression
still be biological?
Evolutionary psychologists argue yes.
 Buss and Shackleford propose that our
ancestors found aggression to be
adaptive.
 Lore and Schultz agree to a point. They
also point out that most species have
developed inhibitory mechanisms.
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Thus, aggression is an optional strategy.
Neurological and Chemical
Influences
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Amygdala (located in the forebrain).
Testosterone – leads to an increase in aggression, but
also increases during aggression
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If testosterone is linked to aggression, does this mean that
men are more aggressive than women?
Maccoby and Jacklin research suggests yes.
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Across cultures, women demonstrate less violence
Further, during era of womens’ liberation, non-violent crime
rate relative to male rate has increased, but not violent crime
rate.
QuickTime™ and a
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Seretonin levels in suicide
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Research on Humans
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General Research Question: Do men show reactive increases in
testosterone after exposure to potential mates?
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Are hormonal responses related to behavioral measures of
courtship?
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Previous research on hormonal responses to sexual stimuli:
 A number of studies have found increased LH or testosterone
levels in men within 10-20 minutes of the onset of exposure to
erotic or sexually explicit films
 However, no published studies have demonstrated increases in
testosterone after more ecologically realistic social interactions
with potential mates
Study Design
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Male subjects (mean age = 21.36) were randomly assigned to a
“male” (n=18) or “female” (n=21) condition
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Subjects engaged in a 5-minute conversation with a male or female
confederate
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Saliva samples were taken before and 15 minutes after the
interaction
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Confederates rated the subjects’ behavior during the interaction.
Effects of Social Interactions on Testosterone
% Change in
Testosterone
30
25
20
15
10
5
0
Male
Female
Expe rimental Condition
Female condition: paired t (18) = 2.10, p = .05, d = .99
Male condition: paired t (17) = 0.90, p = .38, d = .44
Change scores did not differ significantly across conditions
Change in Testosterone by Courtship-Like Behavior
Female Condition
6
Display Scale Ratings
5
4
3
2
1
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
Change in Log Transformed Testosterone Levels
r (19) = .52, p < .05
Roney et al., 2003
Courtship Behaviors
(immediate)
Cues from
Females
Activation of LimbicHypothalamic
Structures
r = .52
Testosterone Increase
(post 20 minutes)
Violence in Hunter-Gatherer Society
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Yanomamo group of hunter-gatherers in Amazon studies over last 25 years
(Napolean Chagnon)
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Inter-tribe violence very common with cycles of killings and retaliations –
Chagnon estimated that about 70% of individuals over age 40 had lost at
least one close genetic kin to homicide
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“…kinship groups that retaliate swiftly and demonstrate their resolve to
avenge deaths acquire reputations for ferocity that deter the violent designs
of their neighbors. … a group with a reputation for swift retaliation is
attacked less frequently and thus suffers a lower rate of mortality. …
Aggressive groups coerce nubile females from less aggressive groups
whenever the opportunity arises. Many appear to calculate the costs and
benefits of forcibly appropriating or coercing females from groups that are
perceived to be weak.”
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Yanomamo men who have killed someone undergo a purification ritual that
gives them the status of “unokai”
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Women almost never unokai
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Chagnon computed that unokai on average had more offspring than nonunokai – 4.91 vs. 1.59 on avg., collapsed across adult age groups
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Men who had killed also had more wives: 1.63 vs. 0.63 on average
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He speculates that men who have killed are both considered more valuable
to the group (avenge and deter attacks from other groups) and thus are
more attractive as mates, and they are able to forcibly acquire
resources/women from other men in the group
Roots of Violence (cont.)
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Biological Factors
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High testosterone linked to higher aggression and
less helping behavior in both males and females
Low levels of serotonin inhibit ability to restrain
aggressive urges
Drive theories—externally elicited drives
arouses motive to harm others
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Frustration-aggression theory not well-supported
because:
 Frustration may lead to sadness, depression
 People may aggress for other reasons (boxers,
soldiers)
XYY- Super Male
Criminal
Chromosomes?
Syndrome
Supermale? Or supercriminal?
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Early work with karyotyping showed that normal men have an X and a
Y sex chromosome, unlike women who have two X chromosomes. In
1961, Sandberg et al. found a man with an extra Y Chromosome
(XYY). Since the Y chromosome codes for ‘maleness’ these individuals
were dubbed ‘super-males’. [Ritter, 1993]
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In 1965 a well-respected geneticist, Patricia Jacobs, stated that the
incidence of XYY condition among the prison population was 20 times
greater than normal. Her study linked the XYY condition with subnormal
IQ and tendencies for violent crime.[Jacobs et.al. 1965].
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The Jacobs study led to sensationalized trials in which lawyers tried to
exonerate the actions of the accused by blaming it on XYY syndrome.
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A belief that XYY males were genetically predisposed to criminal
behaviour encouraged public leaders to call for genetic screening of
newborns and the imposition of interventions to prevent criminal
behaviors from occurring.
Personal Determinants
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Type A behavior pattern
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Hostile attributional style
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Tend to perceive malice in other’s ambiguous acts
Narcissism (inflated self-esteem)
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Type A’s (highly competitive, time-urgent, hostile) tend to be
more aggressive
Tend to lash out if grandiosity is threatened
Gender (higher in males)
Males tend to use direct forms (push, shove, coercion)
 Females tend to use indirect (gossip, spread rumors)
Note: Gender differences disappear under provocation
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What does Bandura say?
Is Aggression Learned?
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Does aggression pay?
Are people reinforced
for aggression?
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If so, operant conditional
suggests that they are
more likely to aggress in
the future.
Social Learning Theory
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Vicarious reinforcement
Bandura’s famous study
with the Bobo doll.
Regional Differences in
Aggression and Social Models
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Homicide rates for White southern males are
substantially higher than for White northern
males (especially in rural areas)
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However, they do not endorse violence in
general, only as a tool for protection of property
and in response to insults: “Culture of honor”
based upon history as herding society
Nisbett research on southerners reaction to
being bumped and cursed at
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More upset (cortisol increase), primed for
aggression (testosterone increase), more likely
to engage in aggression after the incident.
Frustration-Aggression Theory
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Dollard’s original definition: Frustration leads to (hostile)
aggression.
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Is this always true?
Berkowitz revises theory to state
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Frustration is defined as having one’s goal attainment blocked.
Frustration produces anger, which provides a readiness to
agress – but does not guarantee it.
Important concepts include expectations and relative
deprivation.
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American society “creates” frustration.
Theories of Aggression
Negative Affect Theory: Proposed by Leonard
Berkowitz, it states that negative feelings and
experiences are the main cause of anger and
angry aggression. Sources of anger include:
pain, frustration, loud noise, foul odors,
crowding, sadness, and depression.
The likelihood that an angry person will
act aggressively depends on his or her
interpretation of the motives of the people
involved.
Situational Determinants
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Temperature (curvilinear relationship)
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As temp. increases, assaults increase, but only up to a point
(around 90 degrees)
Hotter years (and summers) increased rates of violent crimes, but
not property or rape crimes
Alcohol
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Intoxicated participants behave more aggressively and respond
to provocations more strongly
Alcohol myopia—the more alcohol, the more accepting of
sexual aggression to woman acting friendly (see Figure)
Low aggressors became more aggressive when intoxicated,
whereas high aggressors did not
Heat and Aggression
•
Heat and Aggression
•
Heat and the Bean Ball
•
U-shaped Curve
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Reliable but not very
strong pattern
Alcohol
Strong correlation between
 alcohol use and violent crimes
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Typical Experimental Design
Did they believe they were
drinking alcohol
Yes
No
Yes
25%
25%
No
25%
25%
Did they actually
drink alcohol
cp
Findings
Believe
drinking
alcohol
Aggressive
Are
drinking alcohol
Aggressive
Believe drinking
alcohol and are
drinking alcohol
Most
aggressive
cp
Alcohol & Fear
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Alcohol intoxication is related to behavioral
disinhibition
Many believe alcohol has anxiolytic effects
Some have theorized that alcohol-related
aggression is due to a “fearlessness”
However, there was little evidence to support
these theories
Use startle probe methodology to examine the
effects of alcohol on emotion
Alcohol & Startle
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Have persons view pleasant, unpleasant, and neutral
slides while intoxicated
Compared to non-intoxicated participants overall startle
magnitude was reduced
Startle modulation remained intact
Alcohol seems to effect emotional processing through a
general dampening of brain activity
In contrast to Valium, which inhibits fear reactivity without
effecting overall startle magnitude
Alcohol & Fear
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Alternative hypothesis:
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Perhaps alcohol inhibits fear indirectly through higher cognitive
processes needed to evaluated fearful stimuli under complex
situations
Fewer attentional resources
Diminished ability to use associate memory involved in
processing complex situations, anticipate consequences,
and select appropriate responses
Alcohol & Fear
Experiment with sober and intoxicated
individuals
 Present light cues indicating the possibility
of electric shock
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Green light = “safe”
 Red light = “threat”, might get a shock
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For half the trials present pleasant pictures
as distracters
 Measure startle response
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Alcohol & Fear
Alcohol had an overall effect on startle
magnitude
 In the distracting condition, alcohol also
reduced fear reactivity
 Distracting condition placed the greatest
cognitive demands on participant in
processing of dual stimuli

Alcohol & Fear
Alcohol only reduced fear in when
competing cognitive demands are present
 Alcohol intoxication may serve as model
for behavioral inhibition in complex or
competing stimuli contexts
 Could serve as a model for Factor 2
processes

Frustration and Aggression
•
Dollard, Doob, Miller,
Mowrer, & Sears
•
Frustration always leads to
aggression
•
Frustration is a blocked
goal
•
aggression is first targeted
against agent that is
blocking the goal
•
If that is not possible
aggression is often
displaced
•
cotton prices and lynchings
The Correlation
Between Cotton
Prices and Lynchings
was r = -.67.
Causes of Aggression,
Continued

Alcohol
75% of individuals arrested for crimes of
violence were legally drunk at the time of their
arrests.
 Experimental evidence implies that alcohol
ingestion increases aggression
 Interpretation, alcohol is a disinhibitor. It
seems that under the influence of alcohol a
person’s primary tendencies are revealed
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Causes of Aggression,
Continued
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Pain and Discomfort
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If an animal experiences pain and can’t flee, violence
follows
Most research has been done on heat
Violent crime and aggression increases as
temperature increases (e.g., baseball above 90°)
Confound is increased interaction as it gets warmer
However, lab research suggests that temperature is
key component
Color
Research demonstrates that room color
does not have much of an impact
 However, uniform color has been
demonstrated to be related to an increase in
penalties received (in both football and
hockey)
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Question is: Does wearing a color make you
more aggressive or are referees more likely to
interpret ambiguous situations as aggressive?
Pornography and Violence
Against Women
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Presidential commission on pornography concluded that
explicit sexual material in and of itself did not contribute
to sexual crimes, violence against women, or other antisocial acts.
But…. Violent pornography has been shown to increase
acceptance of sexual violence (Malamuth and
Donnerstein).
Evidence that slasher movies have the same impact.
Social Learning and Mass
Media

TV is full of violent models.
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6 in 10 shows have violence.
By age 10 average child has viewed 8,000
murders on TV.
Few consequences of violence on TV.
High correlation between the amount of TV
watched and viewer’s subsequent aggression
– this data is correlational
Margaret Thomas demonstrated that viewing
TV violence can numb people’s reactions
when they are faced with real-life aggression
Why does media violence affect
us?

When we summarize the ideas in the
research four themes arise:
Seeing others being aggressive weakens our
learned inhibitions against violence.
 Learn techniques, imitate.
 Primes anger. Makes us more aware of
anger.
 Desensitization to violence.

Reducing Aggression

What doesn’t work:
•Viewing violence
•Verbal expression of anger
•Displacing aggression to inanimate objects
Reducing Aggression

What does work:
•Delay
•Distraction
•Relax
•Incompatible response
cp
Theories of Emotion
1. Common Sense Theory
Theories of Emotion
2. James-Lange
“…we feel sorry because we cry, angry because we strike,
afraid because we tremble, and not that we cry, strike or
tremble because we are sorry, angry or fearful.”
-- William James
Facial Feedback Theory

Smiling makes you feel happier
Theories of Emotion
3. Cannon-Bard Theory
Schachter’s
Experiment
Schachter & Singer (1962)

subjects were injected with adrenaline (or a
placebo)

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adrenaline  sweaty palms, increased heart
rate, shakes
some subjects were told they would feel
aroused; some were told nothing
left subjects in a waiting room with a
confederate

euphoria condition


angry condition

Stanley Schachter
1922-1997
confederate played with a hula hoop and made
paper airplanes
confederate asked obnoxious personal
questions (e.g., “With how many men other
than your father has your mother had
extramarital relations: (a) <5; (b) 5-9; (c) >9”
Schachter’s Results
Theories of Emotion
4. Schachter’s Attribution Theory
Cognitive appraisal = TYPE of Emotion
Degree of Arousal = INTENSITY of Emotion
This figure is simpler than Fig. 6.24 (which you can ignore) in your text
Misattribution of Emotion

emotions can be attributed to the
wrong source
(Dutton & Aron, 1974)
 male subjects were asked to meet
the experimenter on a bridge
across the Capilano River in B.C.

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Group 1: Capilano suspension
bridge
Group 2: sturdy modern bridge
attractive female research
assistant interviewed them in the
middle of the bridge and gave her
phone number
Men interviewed on the scary
bridge were more likely to call her
An idea for your next date?
Emotion in the Brain
The Amygdala
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part of the limbic system (with the
hippocampus and hypothalamus)
amygdala = “almond”
processes emotional significance of
stimuli and generates immediate
reactions
damage to amygdala 

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abnormal activation of amygdala 

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inability to recognize facial emotions
absence of fear
absence of conditioned fear response
sudden violent rage
in fMRI studies, the amygdala is
activated by scary stimuli (even if
you’re not aware of them)
Frontal Lobes

Phineas Gage

“Gage is no longer Gage”
Frontal Lobotomies

1935: chimps who were neurotic before surgery
became more relaxed after it

1930s: Egaz Moniz begins frontal lobotomies in
humans (and eventually wins Nobel Prize)

1950s: psychosurgery in vogue; 40,000 frontal
lobotomies in North America

The story of Agnes (Kolb & Whishaw)
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no outward signs of emotion
no facial expression
no feelings toward other people (but still liked her dog)
felt empty, zombie-like
Other patients lose prosody = emotional component of
speech
orbitofrontal cortex

Patients with damage can remember info but don’t
have emotions associated with it
Frontal patients show flat skin
conductance to disturbing stimuli
Right hemisphere specialized for
emotion

Happy or sad?
Why?
right hemisphere specialized for recognizing emotions
Do the two hemispheres have different
personalities?
left hemisphere
activated by positive emotions
left frontal damage  depressed
sometimes overly catastrophic and weepy about injury
diminished left hemisphere activation in depressed people
right hemisphere
activated by negative emotions
right frontal damage  fewer negative emotions
often not appropriately upset or concerned about injury