Aggressive behaviour and Aggressiveness
Posted on : 16-05-2018 Posted by : Admin


When we observe the world around us, we see so much violence. This violence is because of the aggressive behavior. Is aggressive behavior innate or a true nature of animals?

Various philosophers and psychologists have various opinions about the aggressive behavior of humans.

According to philosopher Thomas Hobbes, humans are certainly evil by nature and only the society has the ability to limit the aggressiveness of humans.

On the other hand philosopher Jean-Jacques Rousseau believed that humans are very gentle by nature and that the aggressive behavior is imparted to the humans by the society.

Another well-known psychologist Sigmund Freud opined that humans have both “life instinct,” and “death instinct”. Life instinct is a desire to live and safe self and others whereas death instinct is a desire to ruin self and others.


Definition of Aggression

Aggression is the set of behaviors that not only result in harm to the environment and other animals but also to oneself. This can result in both physiological and physical damage to self and others. Aggressive behavior is violent and unpredictable.

  • Aggression is a part of agonistic behavior that comprises of everything leading to resolution of conflict between individuals.
  • It is used to adjust inter & intra specific conflicts. Conflict arises when two or more individual compete for same object like food, water & space etc.
  • Aggression can take physical, verbal, mental and emotional forms.
  • Aggression is expressed depending upon its intensity from mild to medium.  Facial expression, choosing, grabbing, pushing and lastly fighting and biting are all different forms of aggression.
  • Aggressive behavior is formed of 4 components namely, Agonistic (threat) ,Conflict (fight), Appeasement (submission), Escape (flee)
  • Aggression is made up of complex responses of animal’s nervous & endocrine systems.

Conflict without weapons is not fatal & weakening but, in conflict with weapons individuals can kill each other. Aggressive behaviour is genetically controlled with high degree of heritability and adaptive value.


Purpose of Aggression

Aggressive individuals stand up for their rights and at the same time they ignore the rights of others. They may dominate and humiliate the feeling of others. Though this behaviour is expressive, it is also defensive, unfriendly and self-defeating in nature.

Aggression is influenced by internal and external stimuli, social circumstances, genetic factors, learning processes and frustrating memories.

The following are the purposes of Aggression,

  • To express Possession
  • To express Anger
  • To show dominance
  • To threaten
  • To compete with others
  • To respond to fear
  • To show pain


Types of Aggression

The following are some of the types of Aggressions with examples:

Crowding aggression: Crowding aggression is also known as proximate aggression. It occurs when the animals group-up together to fight for something. For example, a stranger is not allowed into a mice colony. Also, female Iguanas assemble in hundreds of numbers and fight for sandy space between rocks to bury their eggs.

Territorial aggression: Space aggression is also known as territorial aggression. It includes the signals given by the animals to keep the intruders away from a territory.  Most male animals signal other male intruders to keep them away from an area, but these males remain tolerant towards female intruders. For example, when a stranger enters an ant colony, other ants raise alarm through pheromone. African baboons fight for sleeping trees and Seals fight for rocky area.

Breeding aggression: Seasonal change aggression is also known as breeding aggression. This aggression is seasonal in nature and occurs during breeding season.  Male animals threaten and attack competitor males during breeding season. It is interesting to note that male baboons threaten and employ young females to breed in their harems.

Animals like display their strength and weapons to show their aggression. For example Deer show antler, Tigers roar and show canine teeth, wolf hauls and show their full set of teeth.

Pain aggression: The aggressive behavior arising out of previous experience is called as pain aggression. Animals behave and become aggressive in response to pain and previous experiences. For example Dogs which are brought up singly become ferocious when scolded or chained.  Painful experiences would make the dog more violent.

Dominance aggression: The aggression arising out of the dominance over other animals is called as dominance aggression. Dominance aggression is displayed by dominant animals towards subdominant animal group members. For example Lion acts dominant other subdominant animals.

Feeding aggression: Feeding aggression is generally observed in group feeding animal. Many animals fight for resources like food and shelter. For example, Vultures and hyenas fight for food. Feeding aggression is more prominent for the source which is scarce or available seasonally. For example, seasonal fruits and oasis of water

Parental aggression: Nest aggression is also known as parental aggression. Animal show mild forms of aggression at their young ones to warn them against danger, fight, hunters, during weaning. Female animals show parental aggression when they become mothers to protect the young ones from intruders. For example Langoor bites at slightest irritation and Female crocodile guards her baby ferociously. Hermit crabs fight for empty shells

Genetic aggression: Instinct aggression is also known as genetic aggression. Animals of aggressive strain remain aggressive irrespective of the environment in which they are grown.

For example two stains of mice, strain A and strain B were studied. A strain was aggressive and B strain was non aggressive.  Both the young ones were kept in opposite environments. Strain A was kept with less aggressive mothers and B with more aggressive mother.  In other words their living environments were inter-changed.  They were provided with enough shelter, food and water. 

Later it was found that mice of aggressive strain remained aggressive even in peaceful environment while the mice of non-aggressive strain remained non-aggressive even in violent environment. Hence, aggressive behavior is not pathological but it is the part of normal behavioral pattern of all animal species.

Aggressive behavior is essential for the survival of animal.  It can be

  • Accidental (as in case of a frustrated pet dog growling at its owner) or
  • Intended (as in case of a parent being angry with indisplined child)
  • Physical (shown by chasing, biting, slapping)
  • Mental (as in case of a person smiling even in anger)

In 1953, Hess explored hypothalamus and found that lateral and posterior hypothalamus has centers for aggression, attack, fight, emotion or submission.  Also when adrenal gland is removed, aggressiveness decreases. Among vertebrates, it is a generalization that males are more aggressive than females.

  1. Define and explain the meaning of aggression?
  2. What is the purpose of aggression?
  3. Explain five types of aggressive behaviors?
  4. Is the aggressive behavior essential for the survival of the animals? If yes, how does aggression arise?

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