There are different reasons why a person may act aggressively

towards
other human beings. The person may act this way because of his culture
or the way he was brought up in society. The person does not, however,
act this way based on instinct alone. Aggression is a molded, learned
behavior. A human being must have both environmental and instinctual
factors in order to display aggression. Some of a person's natural
instincts are to desire food, reject certain things, escape from
danger, fight when challenged, sex desire, care for the young,
dominate, and to accept inferior status. The combination of instincts
and environment determines a person's behavior. This is based on the
theory that everything human beings do would have to be learned from
other human beings. Aggression must be learned; it is not simply there
from birth. Rather than being an uncontrollable instinct, a person's
behavior is something that is taught to him. For example, a newborn
baby is breathing because it is an involuntary reflex. On the other
hand, a father may tell his young son to beat up the school bully who
is picking on him. As a result, the boy is taught to deal with the
situation by using violence.
In order for an individual to display aggression, it must be driven by
an instinct interacting with that person's surroundings. McDougall
defines the word instinct as "an inherited or innate psycho-physical
disposition which determines its possessor to perceive, and to pay
attention to, objects of a certain class, to experience an emotional
excitement of a particular quality upon perceiving such an object, and
to act in regard to its particular manner, or, at least, to experience
an impulse to such action." This definition basically explains that
people have different reactions for different stimuli. Therefore, an
individual is prone to act a certain way when he is stimulated to do so
from his surrounding environment. For example, the Eskimo does not have
an innate instinct that allows him to survive in his climate. He is
taught to work with his people in order to survive when he is very
young.
When people are brought up in a society, they learn certain customs and
traditions. These customs are usually taught to them because it's part
of their society's way of life, even though some of the customs may
seem cruel and repulsive to others. For example, cannibalism is
abhorrent to us, but in some primitive cultures, to eat an enemy is to
gain his or her strength. This aggressive behavior was taught to the
people of this culture and is the reason for its existence. People need
to have exposure to aggressiveness in society in order to act
aggressive. For example, there was a tribe in New Guinea, the fentou,
who were fierce warriors that were always fighting and killing. The
children of these people learned this hostility from their parents and
then acted in the same way. A parent's method of child rearing lays the
foundation for aggression. The child rearing practices themselves are
the overall design of a particular culture.
When a group of people are isolated, their behavior does not change
unless they interact with other people. The Tasaday tribe is an example
of a group of people who were completely isolated. They showed no signs
of aggression due to the fact that they had no words for weapon,
hostility, anger or war. The Tasaday were a food gathering tribe and
had no use for weapons. The tribe only used knives and other things
that might be classified as weapons as tools to gather food. They also
rejected the spear and the bow and arrow because they could not use
them to gather food. There could not have been anything in their
genetic makeup that made them act in an aggressive or peaceful manner.
This was their way of life that was taught from generation to
generation, and the tribe did what was needed to survive.
The origin of human aggression lies in factors such as society and
culture. Aggression is a learned emotion that is built on different
factors in a person's environment. It is the combination of
environment, society and culture that creates aggressive behavior. It
is the person's natural instincts that are the foundation for the
three. The Tasaday tribe was a peaceful group of people, while the
Fentou were aggressive warriors. Both of the tribes had the ability for
aggression and passivity but were driven to one by their environment,
society and culture