Can seeing others fight harm a small child?

Children are victims even when they are not the direct object of physical abuse. Children who witness violence can be emotionally, psychologically and even physically affected. They could feel anxiety, depression, sleep disorders (nightmares, insomnia, etc) and fear.
Children who witness violence show various mental unbalances in their behavior, such as attention deficit, low self-esteem, sense of guilt and aggressiveness against their classmates, members of the family and property.
Children are particularly vulnerable to trauma by violence, because they feel helpless to prevent it. Children learn to behave by watching the behavior of their parents, siblings, and other adults.