This document discusses aggression, including its definitions, types, biological and social causes, and symptom domains. It begins by exploring various definitions of aggression and how it differs from violence. It then outlines types of aggression such as instrumental vs emotional, sanctioned vs non-sanctioned, and proactive vs reactive. Biological explanations and the neuroanatomy/neurochemistry of aggression are reviewed. Social learning theory, social interaction theory, and excitation transfer theory are presented as theories of aggression. The document discusses demographic and situational factors associated with human aggression. Finally, it examines impulsivity and affective instability as two symptom domains of aggression.
2. What is aggression?
Is aggression defined by behaviours that cause harm?
For example: hitting, pushing versus verbal threats
Is aggression defined by the outcome of behaviour?
For example: Successful versus unsuccessful attempts to
aggress
Or does aggression reside in the intentions of the aggressor?
For example: Harm cause by accident versus harm caused
by intent
3. DEFINITIONS
Derived from the word aggress
means "unprovoked attack”(1610).
Behavior that results in personal injury or destruction
of property (Bandura, 1973)
Behaviour between members of the same species
intended to cause pain or harm((Scherer et al, 1975)
The intentional infliction of some form of harm on
others (Baron & Byrne, 2000)
Behaviour that involves threat or action that
potentially or actually causes pain, withdrawal, or
loss of resources.
4. AGGRESSION VS VIOLENCE
VIOLENCE - extreme, unjustifiable aggression,
usually violating social sanctions and causing
destruction.
It is used almost exclusively to describe
human behaviour.
Violence is physically or psychologically
harmful human aggression that involves the
threat or use of force.
All violence is aggression, but many instances
of aggression are not violent.
6. TYPES OF AGGRESSION
Emotional aggression is
reactive and impulsive
Aggression is driven by
feelings
(e.g., anger), often in
the absence of a
rational cost-benefit
analysis
7. TYPES OF AGGRESSION
SANCTIONED VERSUS NONSANCTIONED
AGGRESSION
• Every society classifies aggression into its own socially
acceptable and unacceptable categories
• Socially sanctioned aggression, depending on culture, might
include rough and tumble play, hunting, police or intelligence
service actions, capital punishment, or war.
• Socially prohibited aggression in most cultures includes criminal
assault, rape, homicide, parenticide, infanticide, child
abuse, domestic violence, torture, civil disturbance, and
terrorism.
• These distinctions are not absolute
8. TYPES OF AGGRESSION
HYPOAROUSAL- VERSUS HYPERAROUSAL-
RELATED AGGRESSION
• Many individuals who exhibit psychopathic traits—
including nonsanctioned aggression, lack of respect for
the rights of others, cruelty, lack of remorse, and lack of
empathy—have been found to have lower-than-usual
resting heart rates and less autonomic reactivity.
• This has led to a classification distinguishing such
hypoarousal-related aggression from the aggression seen
in anxiety disorders, mania, or stimulant
intoxication, which is called hyperarousal related.
9. TYPES OF AGGRESSION
Proactive versus Reactive Aggression
The modern literature on human aggression usually
applies a different typology.
PROACTIVE AGGRESSION (instrumental ,planned,
premeditated, cold-blooded, or predatory aggression)
Actor initiates the aggression against a target without
immediate provocation.
It is atypical in psychiatric emergencies.
REACTIVE AGGRESSION (Hostile, affective, defensive,
hot-blooded, or impulsive aggression ) in the sense that
the actor is responding to a threat.
This is characteristic of violence seen in psychiatric
emergencies
10. Demographics of Aggression
• Age- Violence peaks in the late teens and early 20s
• Sex- Males more than females in general
populations; among people with mental disorders
males and females don’t significantly differ in their
base rates of aggression.
• Social class- three times as likely in lower socio
economic class than in the higher.
• I.Q.- Inversely proportional to violence
11. Demographics of Aggression
• History of substance abuse- Substance abuse tripled the rate
of violence in the non patients in the community and
increased the rate of violence by discharged patients by up
to 5 times
• Education- Less education
• Employment- Lack of sustained employment
• Residential instability- Homeless mentally ill commit 35
times more crimes than domiciled mentally ill(Martell et al,
1995)
• Diagnosis- The higher the number of psychiatric diagnoses,
the greater the rate of aggression.
12. So why study aggression?
During the roughly 5600 years of recorded
history, there have been over 14,400 wars
Humans are one of the few species that
systematically kills members of its own kind
In short, aggression is an important social
problem. Studying the causes of aggression
might suggest strategies for reducing
aggression in society.
13. Biological explanations of aggression
• Freud (1930) argued that human aggressions stems from a
‘Death Instinct’:
– This destructive energy builds up inside us and eventually spills
out in the form of violence against others or against the self
• Lorenz (1966) adapted Darwin’s theory of evolution and
the principle of survival of the fittest:
– He argued that the ‘Fighting Instinct’ is inherent and necessary
for survival
Freud LORENZ
14. NEUROANATOMY AND AGGRESSION
Regions of Brain Associated with Anger/Aggression
• Limbic System
– Amygdala, Hippocampus
Formation, Septum
• Hypothalamus
• Frontal Lobe
15. NEUROANATOMY AND AGGRESSION
• Two neuroanatomical networks, one primarily subcortical, the
other primarily cortical, with both intersecting in the
amygdala—appear to account for processing of human
aggression in the brain.
SUBCORTICAL CIRCUIT LOOP
• supports communication among the amygdala, the hypothalamus, the
nucleus accumbens/septal region and the brainstem.
• The amygdala receives sensory input via the thalamus and the cortex and
assesses whether this is an aggression-provocative stimulus.
• Connections with the brainstem, hypothalamus, and septal area integrate
arousal, serotonergic status, autonomic status.
• The amygdalar signal for an aggressive response tendency is passed via
the looping stria terminalis to the NAc and the VM hypothalamus
16. NEUROANATOMY AND AGGRESSION
CORTICAL CIRCUIT LOOP
• The amygdala is simultaneously communicating with the
cortex.
• Highly processed sensory information about potentially
aggression-provocative stimuli travel from association
regions such as the inferior parietal lobule to reach both
the amygdala and the VMPFC. These regions assess the
threat, opportunity, social significance.
• This assessment is crucial to developing a good motor plan
adjusted via connections with the anterior cingulate gyrus
and DLPFC.
• When the system is working well, a person makes
rapid, appropriate, survival-critical evaluations of the
circumstances, his or her brain juggling largely unconscious
information with conscious awareness, and acts
accordingly, for instance, by fighting or fleeing.
17. NEUROCHEMISTRY OF AGGRESSION
• Virtually every amine neurotransmitter and many peptide and
steroid hormones play a role in the cerebral mediation of
aggression
• Still following questions are unanswered:
• Are ideal subtypes of aggression are mediated by different
transmitters?
• What physiological processes—such as increased or
decreased transmission, activation of pre- versus postsynaptic
receptors, transporter function, or gene expression—account
for observed correlations between levels of neurochemicals
and behaviour?
• The answers to these questions are necessary for best
guesses about likely treatments for subtypes of aggression
and for rational drug discovery.
18. NEUROCHEMISTRY OF AGGRESSION
SEROTONIN:Low serotonergic function are more common
in impulsive aggression.
• These findings have led to simplistic conclusion that serotonin
is an aggression damper.
• Risperidone actually have more antagonist effect at 5-HT2A
than at D2 receptors and useful in decreasing aggression.
NOREPINEPHRINE AND EPINEPHRINE:
• PERIPHERAL AROUSAL FUNCTION: Helps to face a threat such
as an anticipated fight via sympathetic nervous system
activation, adaptive changes in cardiovascular status.
• The effects of NE on aggression may be mediated to some
degree by its effect on corticotropin-releasing factor (CRF) and
steroid hormone metabolism.
• α-2 agonists such as clonidine decreases aggression in
hyperactive or autistic children.
19. NEUROCHEMISTRY OF AGGRESSION
DOPAMINE: Mesocorticolimbic arm of the DA
system, is involved in regulation of aggression.
• DA activity appears to play an indirect, permissive role.
• One theory is that aggression is often intrinsically rewarding.
In the absence of DA stimulation of reward
centers, motivation for aggression is decreased.
GABA: GABAergic transmission paradoxically increases
aggression.
• Benzodiazepines—which positively affect GABAA reception—
sometimes make humans angry and aggressive.
• Animal studies of this phenomenon show that low doses of
benzodiazepines increase whereas higher doses decrease
aggression.
20. NEUROCHEMISTRY OF AGGRESSION
TESTOSTERONE: Influence of testosterone on overt aggression
depends both on fetal and pubertal brain exposure.
• Rough correlations are found between testosterone levels and
aggression, high testosterone is probably more predictive of dominance
seeking and dominance winning than of violence.
• Finally, testosterone hardly acts in isolation. We are just beginning to
uncover neurochemical interactions that help to explain the role of this
hormone in inappropriate aggression.
CORTISOL: Chronically low salivary cortisol levels are associated
with disruptive, aggressive behavior in boys.
• Decreased cortisol levels have also been reported in adolescent girls with
conduct disorder.
• Yet not all findings are consistent with this low-cortisol–aggression
association
21. Theories of Aggression
Cognitive Neoassociation Theory
• Berkowitz (1993) has proposed that aversive events such as
frustrations, provocations, loud noises, uncomfortable
temperatures, and unpleasant odors produce negative affect.
• Negative affect automatically stimulates various thoughts,
memories, expressive motor reactions, and physiological responses
associated with both fight and flight tendencies
• The fight associations give rise to rudimentary feelings of anger,
whereas the flight associations give rise to rudimentary feelings of
fear
• Cognitive neoassociation theory not only subsumes the earlier
frustration-aggression hypothesis (Dollard et al. 1939), but it also
provides a causal mechanism for explaining why aversive events
increase aggressive inclinations, i.e., via negative affect
22. Theories of Aggression
Social Learning Theory
• According to social learning theories
(Bandura 2001), people acquire aggressive
responses the same way they acquire other complex
forms of social behavior—either by direct experience
or by observing others.
• It explains the acquisition of aggressive
behaviors, via observational learning processes and
provides a useful set of concepts for understanding
and describing the beliefs and expectations that
guide social behavior.
23. Theories of Aggression
Social Interaction Theory
• Social interaction theory (Felson 1994) interprets aggressive
behavior (or coercive actions) as social influence
behaviour, i.e., an actor uses coercive actions to produce
some change in the target's behaviour.
• Coercive actions can be used by an actor to obtain something
of value
(e.g., information, money, goods, sex, services, safety) to
bring about desired social and self identities
(e.g., toughness, competence)
• This theory provides an excellent way to understand recent
findings that aggression is often the result of threats to high
self-esteem
24. Theories of Aggression
Excitation Transfer Theory
• This theory suggests that arousal from one situation can
be transferred to another situation.
• If two arousing events are separated by a short amount
of time, arousal from the first event may be
misattributed to the second event. If the second event is
related to anger, then the additional arousal should make
the person even angrier.
25. Social Causes of Human Aggression
Frustration
• Does not always lead to some form of aggression
• Aggression does not always result from frustration..
• However, it can elicit aggression when the cause of the
frustration is viewed as illegitimate or unjustified.
Provocation
• Physical or verbal provocation is one of the main causes of
aggression.
– People tend to reciprocate with the same or slightly
higher level of aggression that they receive from others.
– Condescension, the expression of arrogance is a strong
predictor of aggression
Heightened arousal
• Arousal in one situation can increase aggression in response
to provocation, frustration, etc. in another, unrelated
situation
26. Causes of Human Aggression
• Exposure to Media Violence
• May be a factor that contributes to high levels
of violence in countries where it is viewed by
many people
–This is supported by short-term laboratory
experiments and longitudinal studies.
• It can prime aggressive thoughts and lead to a
hostile expectation bias that others will behave
aggressively, which causes individuals to act
more aggressively
• Violent Pornography
• Can increase the likelihood that men will
aggress against women
• Can desensitize people to victims of sexual
violence
27. Personality factors in Human Aggression
Narcissism
The holding of an over-inflated view of one’s virtues or
abilities.
‘Type A’ personality (drive to achieve, time
urgency, competitiveness, and hostility) is associated with:
higher aggression in competitive tasks (Carver &
Glass, 1978)
greater likelihood to engage in child abuse (Strube et
al., 1984)
greater conflict with peers in workplace (Baron, 1989).
Hostile attributional bias:
The tendency to attribute hostile intentions to others
(Graham et al., 1992)
28. Causes of Human Aggression
Situational Determinants of Aggression
• Alcohol
–Intoxication facilitates aggression by
impairing cognitive processing, narrows
attention
–Result is more extreme, less moderated
behavior
–Aggressive response: often powerful and
simple
–Inhibiting response: often weaker and more
complex
29. So what causes aggression?
There is no single answer (… sorry).
Theories have been proposed at all levels of
analysis:
biology
individual personality
specific situations
broader cultural norms and values
30. So what causes aggression?
• Aggression is likely to be the outcome of a
complex process that involves multiple factors
• Biological process related to arousal and the
experience of emotion.
• Individual differences in the interpretation of
incoming information.
• Situational cues that exacerbate hostility or
trigger an aggressive response.
• Norms and values about what is and is not
appropriate.
31. Symptom Domains
1. Impulsive (rapid, thoughtless, aggressive
acts)
2. Affective instability (affectively charged
attacks with seemingly little provocation)
3. Anxiety/hyperarousal (overwhelming anxiety
and frustration leading to aggressive
outbursts)
32. Impulsivity
I. The failure to resist and impulse, drive, or temptation, resulting in rapid,
unplanned reactions to internal and external stimuli.
A. Inability to delay reward where the individual is unable to modify
his or her behaviour according to the context of the situation or to reflect
on the consequences of the behaviour, thus impairing judgment.
B. Underestimated sense of harm or lack of regard of the negative
consequences.
II. Impulsive aggressive disorder is defined as recurrent incidents of
physical or verbal aggression that are out of proportion to the
circumstances, occur at least twice a week for more than one month and
lead to marked distress and impairment.
33. Affective Instability
I. Emotional regulation is described as the
ability to manage arousal or to modulate the
intensity of emotional reactions.
A. Emotional regulation develops biologically
and dysregulation is common to several
disorders:
1. Bipolar patterns
2. Developmental disorders like autism
spectrum disorders.
34. Affective Instability
II. Affective instability is emotional dysregulation expressed
as exaggerated reactions to negative or frustrating stimuli,
which may result in rage or aggression.
A. In children and adolescents affective instability usually
occurs rapidly and is highly reactive.
III. Affective instability may be combined with impulsivity to result in
risky and aggressive behaviour, but the two do not describe the same
phenomenon; a person can be impulsive with or without the aggressive
component.
A. Pure impulsive aggression has no identifiable precedent, seemingly
coming out of the blue.
B. Affective aggression usually happens rapidly and may seem
impulsive, but is differentiated by the preceding rush of affect, resulting in
“hot tempered” aggression
Both affective instability and impulsivity are related to poor
attention, attention shifting, and verbal self-control.
35. Anxiety/ Hyperarousal
I. Anxiety is an emotional response linked to a
threatening stimulus, even in the absence of
direct danger.
II. Anxiety may be considered part of a normal
response until it becomes excessive or difficult to
tolerate, resulting in overstimulation.
III. As coping tolerance is exceeded, the anxious
hyperarousal may precipitate decompensation
and disorganization, resulting in poorly directed
aggression towards self or others, sleep
disturbances, irritability, difficulty
concentrating, hypervigilance.
36. VARIOUS RISK FACTORS CONTRIBUTE TO DEVELOPMENT
OF AGGRESSION IN A PSYCHIATRIC PATIENT:
PSYCHOSIS
Schizophrenia, particularly paranoid schizophrenia
patients, may be at risk, especially in the active phases of
their illness to commit violent acts. General risk factors
for violence in such patients include:
• Presence of hallucinations, delusions, or bizarre
behaviors (paranoid patients with delusions may be at a
higher risk to commit a violent act because of their
ability to plan and their retention of some reality testing)
• Substance abuse
• Presence of neurological impairment
• Being male, poor, unskilled, uneducated, or unmarried
37. PERSONALITY DISORDERS
Traits associated with aggression are
(Nestor, 2002):
• Impulsivity
• Low frustration tolerance
• Inability to tolerate criticism
• Tendency to have superficial relationships and to
dehumanize others
• Failure to accept responsibility for one’s actions
• Cold, lack of empathy
• Lack of remorse
38. Dementia
– Impaired executive functioning
– Increased agitation
– Sometimes hallucinations and/or delusions
Mania
– More likely to be assaultive without prior threat although often respond
violently to any limit setting
– 26% of patients with mania attack someone within the first 24 hours of
hospitalization
Depression
– Despair, in rare cases could lead to striking out against other people
– Murder-suicide is suicidal within 1 week of a homicide; in couples it is highly
associated with jealousy (Felthous et al, 1995)
– The individual can no longer endure a life without what is perceived to be a
vital element (e.g., a spouse, family, job, health) but can’t bear the thought of
the other persons carrying on without him, so he forces the others to joint him
in death. Suicidal mother hence, should always be asked about her children.
40. Substance Abuse or Medication Effects and Aggression
Alcohol
Cocaine
Methamphetamine
Anabolic Steroids
Phencyclidine
41. Childhood Neuropsychiatric Disorders and Aggression
Aggression is among the most common reasons for
psychiatric referral of children and adolescents.
60 percent of referrals to outpatient child psychiatric
clinics explicitly for evaluation and treatment of
aggression.
Disorders frequently associated with aggression are
• Mental Retardation (MR)
• Autistic Disorder
• Pervasive Developmental Disorder
• Attention-Deficit/Hyperactivity Disorder (ADHD)
• Oppositional Defiant Disorder (ODD)
• Conduct Disorder (CD).
44. Pharmacological
Medications are often used to manage agitated behavior
These include :
• Antipsychotics (eg
Risperidone, olanzapine, clozapine)
• Benzodiazepines (eg lorazepam)
• Mood stabilizers(eg lithium, valproate, and
carbamazepine )
• Antidepressants (eg SSRIs )
• Anxiolytics
• Beta-adrenergic blockers, in particular propranolol.
45. MANAGEMENT OF ACUTELY VIOLENT PATIENT
Acute behavioural disturbance can occur in the
context of psychiatric illness, physical illness,
substance abuse, or personality disorders etc.
Doctor’s primary goal in the emergency
situation :
• violence risk assessment
• to keep the patient safe
• to arrive at rapid stabilization and disposition of
the patient
46. STEPS IN MANAGEMENT OF ACUTELY
VIOLENT PATIENT
STEP 1 : To to de-escalate acute aggression:
Assess the environment for potential dangers (eg, objects that
can be thrown or used as a weapon).
Take verbal threats seriously.
Remain several feet away to avoid crowding the patient.
Clear the area of other patients.
Remain calm, maintain a confident and competent
demeanor, and attempt to deescalate by engaging the patient
in conversation.
Avoid arguments between staff members in front of the
patient.
If restraints are necessary, have at least 4 people available
47. MANAGEMENT OF ACUTELY VIOLENT PATIENT
STEP 2: Offer oral treatment
A regular antipsychotic(olanzapine, haloperidol) /lorazepam 1-2
mg.
STEP 3: Consider IM treatment
• Lorazepam 1–2 mg/Promethazine 50 mg/Olanzapine 10
mg/Haloperidol 5 mg
• Repeat after 30–60 min if insufficient effect
STEP 4: IV treatment
• Diazepam 10 mg over at least 5 minutes.
• Repeat after 5–10 minutes if insufficient effect (up to 3 times)
48. Treatment of Aggression in Schizophrenia and
Schizoaffective Disorder:
A. NONPHARMACOLOGICAL INTERVENTIONS:
• Comparatively less effective
• Combination of group-based cognitive skill training with a stepwise
system of rewards for target behaviours may be useful.
B. PHARMACOLOGICAL INTERVENTIONS:
• Atypical agents have been more effective than typical agents in reducing
aggression.
• Clozapine is postulated to have a specific antiaggressive benefit
• But risks of clozapine to bone marrow may outweigh its possible
superiority as an antiaggression treatment
• A provisional treatment recommendation is that risperidone may be a
useful first choice. If it fails olanzapine or even clozapine may be used.
• It is unclear whether concomitant antidepressant or mood-stabilizing
therapy will boost the antiaggressive benefit in schizoaffective patients
49. Treatment of Aggression in Borderline Personality Disorder
(A)Nonpharmacological Interventions:
• Transference-focused psychotherapy may be
beneficial.
(B)Pharmacological interventions
• Aggressive BPD patients with prominent
affective disturbance may benefit from mood
stabilizers( e.g. divalproex sodium )
• Those with prominent idiosyncratic
thoughts, especially paranoia, may do better
with antipsychotics.
50. TREATMENT OF AGGRESSION IN ALZHEIMER'S
DISEASE AND RELATED DEMENTIAS
(A)Nonpharmacological Interventions:
• The benefits of nonpharmacological therapies depend on the level
of cognitive decline.
• Unfortunately by the time aggression is a significant problem, most
patients have lost the ability to follow the nonpharmacological
methods.
• Structured activities, music therapy, and even aromatherapy have
been reported to reduce agitation
(B)Pharmacological Interventions:
• Atypical antipsychotic agents are the most prescribed medications.
• Low-dose risperidone and olanzapine are the best-supported
choices
51. Treatment of Aggression in TBI
(A)Nonpharmacological Interventions:
• Higher-functioning patients may significantly benefit
from CBT, supportive, or insight-oriented
psychotherapy.
• Behavioral modification methods helpful for patients
with poor cognitive outcomes.
(B)Pharmacological Interventions:
• A useful provisional treatment recommendation
is that for reactive/impulsive aggression or
irritability after TBI propranolol in doses
beginning at 10 mg twice a day is a reasonable
first choice.
52. Treatment of Selected Aggressive Behaviours
Primarily Seen in Childhood and Adolescence
• Nonpharmacological Interventions are less
effective.
• Most commonly used drug is risperidone.
• Mood stabilizers such as Divalproex
sodium, carbamazepine , Lithium etc may be
useful.
• α-adrenergic agonist clonidine
• Stimulants
53. Aggression Research Today and in the Future
The link between brain activity and human aggression is a
promising area of current and future research, both in terms
of understanding those brain structures that are implicated in
aggressive responding (e.g., Weber et al., 2006) and in terms
of the effects of internal and external triggers on neural
responses and how these relate to aggression
(e.g., Bartholow et al., 2006).
A related area of work that holds considerable promise for
vastly improving our ability to predict who will be violent
under what circumstances is behavioural genetics.
54. Researchers are beginning to discover variations in the
regulation of neurochemicals linked to aggression and
variations that ultimately have genetic causes and that can be
targeted for pharmacological and behavioral interventions to
reduce their influence on the expression of aggressive
behaviour (e.g., See et al., 2008).
A third promising research direction is apology and
forgiveness (e.g., McCullough, 2008). Hopefully social
psychologists will be at the forefront, conducting research on
these and other important topics that ultimately have the
potential to make the world a less violent, more peaceful
place
Aggression Research Today and in the Future
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