CHAPTER THREE
CHAPTER OBJECTIVES
► Know the difference between affective and instrumental aggression.
► Understand the biological and ethological explanations of aggression.
► Appreciate the frustration-aggression hypotheses.
KEY TERMS
Aggression Affective aggression
Instrumental aggression XYY Syndrome
Instincts Modeling
Konrad Lorenz Five-factor model
Heat of passion killing Justifiable homicide
LECTURE NOTES
Aggression and Violent Crime
Biological theories of aggression include “body constitution” theories (also called physiognomy).
Physiognomy was the study of facial features.
Phrenology was the study of bumps on the head.
The book The Criminal Man (Cesare Lombroso, 1876) represented the belief that certain people
are “born criminal” and that such individuals were throwbacks to an earlier, primitive, stage of
evolution.
The XYY “Super Male” Syndrome (1960s):
Researchers believed that the extra Y chromosome was responsible for increased aggressiveness
as such individuals were found to an inordinate degree in prison populations. More recent
research has indicated that these individuals have low IQ scores, learning disabilities, and
Ethological theories = the study of animal behavior.
Instincts = genetically-programmed behavior.
Konrad Lorenz was one of the most influential ethologists. Lorenz studied the nature of
instinctive behavioral acts. He used a “hydraulic model” to explain behavior: action depends on
the accumulation of energy. He argued that fighting and warlike behavior in man had an inborn
basis. Modern research has not supported this view.
Social learning theory (Bandura, 1960s) holds that the acquisition and maintenance of
aggressive behavior are developed largely through observation, modeling, and reinforcement.
By observing the consequences of aggression, a child gradually acquires knowledge of rules of
conduct. Bandura believed that family members serve as the most prominent source of behavior
modeling. He also maintained that television (and movies), provide powerful sources of
behavior modeling, and consequently the concerns about showing violence being rewarded in
these media.
Individuals with a narcissistic personality disorder are also prone to aggression. Such
individuals show a sense of entitlement, lack of empathy, arrogance, and a tendency to exploit
other people for their own selfish needs.
The concept of boredom was first introduced as a construct associated with aggression in the
1960s by psychoanalysts, notably Erich Fromm. Fromm and others believed that “bored
characters” attempt to fill their internal psychological “void” with compulsive activity, even
aggressive behavior. Such individuals also do not tolerate true boredom well and may seek
action (even violence) as a means of sustaining themselves when bored.
The disinhibition hypothesis states that alcohol may disrupt normal brain functioning and
weaken the brain’s ability to restrain impulsive behaviors. The same type of effect has not,
however, been found with drugs such as cocaine or cannabis.
Case reports suggest that high doses of anabolic steroids increase irritability and aggression.
Homicide is the killing of a human being caused by another. It is a neutral term under the law
and does not in and of itself imply criminality or intent.
Like most crimes, murder has two components: the physical act of the crime, and the intent.
The physical aspect of a crime is called the actus reus.
The deadly weapon doctrine also helps to establish intent. The doctrine states that one who
intentionally uses a deadly weapon on another human being and thereby kills him, presumably
intended to kill him.
According to the doctrine of transferred intent, if A intends to kill B, shoots and misses and
hits C, A is guilty of the murder of C.
In order for the felony murder rule to hold, the defendant’s actions must have been the
proximate cause of the death, or the death must have been foreseeable as a possible result of the
defendant’s actions.
The death in felony murder must usually occur during the crime itself or during the preparation
for the crime. This is the res gestae theory.
First degree murder is murder committed with premeditation and deliberation. Some
jurisdictions include as first degree murder, murder committed with atrocity, torture, or by lying
in wait.
Voluntary manslaughter is an intentional homicide committed under mitigating circumstances.
The most common mitigating circumstance is heat of passion killing. Provocation, caused by
words alone are not sufficient to provide adequate provocation to reduce a charge of murder to
voluntary manslaughter.
Mutual combat: When two people engage in mutual combat that is not deadly by design, but
one fighter decides to kill the other during the fight and does so, it is manslaughter and not
murder. But the fight must clearly be “mutual” for this rule to apply.
Involuntary manslaughter is an unintentional homicide committed without malice, which is
neither justified nor excused.
There are generally two types of involuntary manslaughter:
(1) Criminal negligence manslaughter results from conduct that involves a high degree of
risk of death or serious injury (e.g. a camper leaves a campfire burning which later burns
The main prerequisite to a defense of self-defense is that the use of deadly force was
based on the reasonable belief that one’s life was in danger, or that one was in danger of
great bodily harm, and that the use of deadly force was necessary to prevent such harm.
Excusable homicides are homicides which are not criminal but also not justified under the
law. These include: duress, necessity, involuntary intoxication, mistake of fact, mistake of
law, and incapacity (infancy, insanity).
Duress is any unlawful threat or coercion used by a person to induce another to act (or to
refrain from acting) in a manner he or she otherwise would not (or would).
Common law rape is unlawful sexual intercourse with a female without her consent. It would be
rape for a man to have intercourse with a woman who has fainted, is drugged, intoxicated,
unconscious, or insane.
SUMMARY
In this chapter we defined aggression and violence and differentiated affective from
instrumental aggression. We examined some of the classic theories used to explain aggressive
and violent behavior such as the instinctual hydraulic model of Lorenz and others, the XYY
syndrome, Sheldon’s somatotyping model, and the frustration-aggression hypothesis as proposed
In order for there to be a homicide the victim must be a “life in being” and the death must
be caused by another. Murder was defined as the unlawful killing of a human being committed
with malice. Murder, like all crimes, requires an actus reus which is the act (or omission) that
comprises the physical elements of a crime, together with a mens rea which is the mental
component of the crime or the “guilty mind.” Mens rea is sometimes a difficult thing to
establish. But it is clearly established when a deadly weapon is used in the commission of a
crime. It is also clearly established when the defendant’s conduct creates an extremely high risk
of death to the victim.
Voluntary manslaughter consists of an intentional homicide under extenuating
circumstances, such as killing in the “heat of passion.” In order for such an extenuating
circumstance to be effective, however, the situation must be one which would arouse the passions
of a reasonable person. Involuntary manslaughter is an unintentional homicide, committed
without malice, which is neither justified nor excused. An example would be where a person
plays with a loaded weapon in the presence of others and it goes off killing one of those present.
execution of his official duties. Excusable homicides are those homicides to which the law does
not attach criminal guilt. These include homicides done under duress, necessity, involuntary
intoxication, mistake of fact, mistake of law, and incapacity (infancy, insanity).
Most states do not have a separate category of crime known as “domestic violence,” but
these offenses are usually handled through existing laws. Child abuse and neglect is defined as
“any recent act or failure to act on the part of a parent or caretaker which results in death, serious
physical or emotional harm, sexual abuse or exploitation.” In every state, the following people
REVIEW QUESTIONS
1. How does aggression differ from “violence?” Differentiate affective aggression from
instrumental aggression.
2. What is the frustration-aggression hypothesis? How is it similar to the revised
frustration-aggression hypothesis?
3. Who according to Bandura, what group is the most prominent source of behavior
modeling for children?
9. What is the common law definition of rape? How has this definition been statutorily
modified in many states?