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					                 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       No. of films
 1920s        2
 1930s        3
 1940s        3
 1950s        4
 1960s        12
 1970s        20
 1980s        23
 1990s        64

     Serial murder Films USA
50                             1940s
40                             1950s

30                             1960s
            No. US Films
     General Serial Killer Profile
   Male (88.3%)
   White
       80% of all serial killers
       73% of male serial killers
       93% of female serial killers
   Average intelligence
       107 in our data base
       n = 71
   Often a police groupie
   Seldom involved with groups
    General Serial Killer Profile
       Demographics – Average age is 28
   Males
       27.5 is average age at first kill
            9 is the youngest (Clarence Hill)
            72 is the oldest (Ray Copeland)
       Jesse Pomeroy (Boston in the 1870s)
            Killed 28 people by the age of 14
            Spent 58 years in solitary confinement until he died
   Females (Kelleher & Kelleher, 1998)
       30 is average age at first kill
            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          Percentage

     White             80.1%

     Black             13.0%

     Hispanic          4.5%

     Asian             2.4%
    General Serial Killer Profile
   Unstable home (37%)
   Absence of loving and nurturing relationship
   Physical ailments and disabilities
   Head injuries
   Triad
        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          Serial Killers
Physical             6%                 36%

Sexual               3%                 26%

Psychological        2%                 50%

Neglect              18%                18%

Other                6%             Not applicable

No Abuse             70%                32%
    General Serial Killer Profile
        Forensic History
   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
  Most frequently selected victims
          [Hickey (2002; 399 serial killers)]

Strangers (70%)            Acquaintances (20%)       Family (10%)
1. College students,       1. Friends and            1. Own children
      prostitutes                neighbours          2. Husbands
2. Little boys and girls   2. Girlfriends and        3. Wives
3. Hitchhikers                   boyfriends          4. In-laws
4. People at home          3. Waitresses and         5. Nephews, nieces
5. Handicapped people            prostitutes         6. Own mother
6. Store-owners,           4. Co-workers             7. Sibling
       landlords           5. Landlords,             8. Grandparents
7. People walking                employers, guards
       street              6. Gang members
8. Older women             7. Patients
9. Police officers
10. Derelicts/transients
11. People responding
       to newspaper ads
        Male Serial Killers(399):
 1. Firearms mainly (41%)
                              1. Sex (55%)
 2. Suffocation (37%)
                              2. Control (29%)
 3. Stabbing (34%)
                              3. Money (19%)
 4. Bludgeoning (26%)
                              4. Enjoyment (16%)
 5. Firearms only (19%)
                              5. Racism and hatred (11%)
 6. Poison (11%)
                              6. Mental problems (6%)
 7. Drowning (3%)
                              7. Cult-inspired (5%)
 8. Other (2%)
                              8. Attention (2%)
       Female Serial Killers (62):
 1. Poison (80%)        Motives
 2. Shooting (20%)         1. Money (74%)
 3. Bludgeoning (16%)
                            2. Control (13%)
 4. Suffocation (16%)
                            3. Enjoyment (11%)
 5. Stabbing (11%)
                            4. Sex (10%)
   6. Drowning (5%)
                            5. Drugs, cult involvement,
                             cover up, or feelings of
                             inadequacy (24%)
     III. Female Serial Killers & their
   Female serial killers tend to be "black
    widows" who kill a succession of husbands,
    lovers, or other family members.

   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):
     1,430,693 in 1999
     1,425,486 in 2000
     1,439,480 in 2001
     1,426,325 in 2002
       What did Freud say?
 Eros: Life force
 Drive-thwarted
 Instinct
 Catharsis
 Thantos: death force
           What did Freud say?
    "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
         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 reaction-
    formations. 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?
   Hobbes, Freud, and Lorenz say yes.
   Freud and Lorenz in particular believe that aggressive
    energy builds up and must be released.
       Catharsis theory.
       Unfortunately, aggressive catharsis frequently leads to more
   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
   Instinct- innate (unlearned) behavior pattern
       Freud- redirecting the ―death instinct‖ (thanatos) to
       Lorenz- inherited ―fighting instinct‖ developed through
        the course of evolution (strongest survive)
    Not supported because:
       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
 Lore and Schultz agree to a point. They
  also point out that most species have
  developed inhibitory mechanisms.
       Thus, aggression is an optional strategy.
             Neurological and Chemical
   Amygdala (located in the forebrain).
   Testosterone – leads to an increase in aggression, but
    also increases during aggression
       If testosterone is linked to aggression, does this mean that
        men are more aggressive than women?
   Maccoby and Jacklin research suggests yes.
       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
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                     Research on Humans

   General Research Question: Do men show reactive increases in
    testosterone after exposure to potential mates?

   Are hormonal responses related to behavioral measures of

   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
   Male subjects (mean age = 21.36) were randomly assigned to a
    ―male‖ (n=18) or ―female‖ (n=21) condition

   Subjects engaged in a 5-minute conversation with a male or female

   Saliva samples were taken before and 15 minutes after the

   Confederates rated the subjects‘ behavior during the interaction.
                Effects of Social Interactions on Testosterone

% Change in

                              Male                            Female
                                     Experim ental 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


        Display Scale Ratings




                                 -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

            Activation of Limbic-
Cues from   Hypothalamic
Females                                           r = .52

                                    Testosterone Increase
                                      (post 20 minutes)
        Violence in Hunter-Gatherer Society
   Yanomamo group of hunter-gatherers in Amazon studies over last 25 years
    (Napolean Chagnon)

   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

   ―…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.‖
   Yanomamo men who have killed someone undergo a purification ritual that
    gives them the status of ―unokai‖
        Women almost never unokai

   Chagnon computed that unokai on average had more offspring than non-
    unokai – 4.91 vs. 1.59 on avg., collapsed across adult age groups

   Men who had killed also had more wives: 1.63 vs. 0.63 on average

   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.)
   Biological Factors
       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
       Frustration-aggression theory not well-supported
          Frustration may lead to sadness, depression
          People may aggress for other reasons (boxers,
XYY- Super Male
Criminal Chromosomes?
Supermale? Or supercriminal?
   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]

   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 1965].

   The Jacobs study led to sensationalized trials in which lawyers tried to
    exonerate the actions of the accused by blaming it on XYY syndrome.

   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
   Type A behavior pattern
       Type A‘s (highly competitive, time-urgent, hostile) tend to be
        more aggressive
   Hostile attributional style
       Tend to perceive malice in other‘s ambiguous acts
   Narcissism (inflated self-esteem)
       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
What does Bandura say?
          Is Aggression Learned?
   Does aggression pay?
    Are people reinforced
    for aggression?
       If so, operant conditional
        suggests that they are
        more likely to aggress in
        the future.
   Social Learning Theory
       Vicarious reinforcement
       Bandura‘s famous study
        with the Bobo doll.
           Regional Differences in
        Aggression and Social Models
   Homicide rates for White southern males are
    substantially higher than for White northern
    males (especially in rural areas)
       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
       More upset (cortisol increase), primed for
        aggression (testosterone increase), more likely
        to engage in aggression after the incident.
    Frustration-Aggression Theory
   Dollard‘s original definition: Frustration leads to (hostile)
       Frustration is defined as having one‘s goal attainment blocked.
   Is this always true?
   Berkowitz revises theory to state
       Frustration produces anger, which provides a readiness to
        agress – but does not guarantee it.
   Important concepts include expectations and relative
       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
           Situational Determinants
   Temperature (curvilinear relationship)
       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
       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
    •   Reliable but not very
        strong pattern

   Strong correlation between
 alcohol use and violent crimes
Typical Experimental Design

                         Did they believe they
                         were drinking alcohol

                           Yes           No

                   Yes     25%          25%
    Did they
  actually drink
     alcohol       No      25%          25%

                                  Believe drinking
   Believe            Are         alcohol and are
                                  drinking alcohol
               drinking alcohol

Aggressive    Aggressive             Most
               Alcohol & Fear
   Alcohol intoxication is related to behavioral
   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
   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
   Alternative hypothesis:
       Perhaps alcohol inhibits fear indirectly through higher cognitive
        processes needed to evaluated fearful stimuli under complex
   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
 Present light cues indicating the possibility
  of electric shock
     Green light = ―safe‖
     Red light = ―threat‖, might get a shock
 For half the trials present pleasant pictures
  as distracters
 Measure startle response
            Alcohol & Fear
 Alcohol had an overall effect on startle
 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
                              Frustration and Aggression

•   Dollard, Doob, Miller,
    Mowrer, & Sears                             The Correlation
•   Frustration always leads to
                                                Between Cotton
•   Frustration is a blocked
                                                Prices and Lynchings
    goal                                        was r = -.67.
•   aggression is first targeted
    against agent that is
    blocking the goal
•   If that is not possible
    aggression is often
•   cotton prices and lynchings
         Causes of Aggression,
   Alcohol
     75% of individuals arrested for crimes of
      violence were legally drunk at the time of their
     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
            Causes of Aggression,
   Pain and Discomfort
       If an animal experiences pain and can‘t flee, violence
       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

 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
       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
   Presidential commission on pornography concluded that
    explicit sexual material in and of itself did not contribute
    to sexual crimes, violence against women, or other anti-
    social acts.
   But…. Violent pornography has been shown to increase
    acceptance of sexual violence (Malamuth and
   Evidence that slasher movies have the same impact.
     Social Learning and Mass
   TV is full of violent models.
       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
   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
     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:



      •Incompatible response

   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
                            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
                            euphoria condition
                                 confederate played with a hula hoop and made
                                  paper airplanes
                            angry condition
                                 confederate asked obnoxious personal
                                  questions (e.g., ―With how many men other
                                  than your father has your mother had
Stanley Schachter                 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.
                    Group 1: Capilano suspension
                    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
   part of the limbic system (with the
    hippocampus and hypothalamus)
   amygdala = ―almond‖
   processes emotional significance of
    stimuli and generates immediate
   damage to amygdala 
        inability to recognize facial emotions
        absence of fear
        absence of conditioned fear response
   abnormal activation of amygdala 
        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)
           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

      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
   Happy or sad?

  right hemisphere specialized for recognizing emotions
Do the two hemispheres have different
  left hemisphere
    activated by positive emotions
    left frontal damage  depressed
       sometimes overly catastrophic and weepy about injury
    diminished left hemisphere activation in depressed

  right hemisphere
    activated by negative emotions
    right frontal damage  fewer negative emotions
       often not appropriately upset or concerned about injury