There have been so many attempts to understand the human behavior, yet it refuses to come into the grasp or to follow some general formula. Wise men started with animals (we being one of them) and the father of Evolution , Charles Darwin, came to conclusion that “The species always compete for the resources and those who the fittest among them survive and ready themselves for another competition”. This is the way all living beings have evolved over millions of years. Humans are endowed with most complex brain and sit at the top echelon of the evolution ladder. Charles Darwin assumed that improvement or the evolution is gradual process taking place continuously.
There are flaws in this line of approach to explain the observations. Some scientists, most notably Stephan Jay Gould, have come to conclusion that evolution had not taken place at a regular pace but in the bursts of intense activity followed by hiatus of considerably long periods.
Then there were people like Peter Alekseyevich Kropotkin, the Russian prince who renounced his aristocracy and settled in England in a fishing village, who held the diagrammatically opposite view. He argued that human beings tend to live in cooperation and help each other. Not only human beings, he observed so many animals living in groups in the Siberian forests where the food is scarce due to extreme cold. He said that human beings are good at heart.
The latest theory is that behind every human action there is a selfish motive which may be tangible or intangible. It is argued that why a person tries to save a child from fire or a person from drowning even if a stranger, is that if he or she does not do it, afterwards his or her conscience will torment and the person will get tension. So to avoid the mental stress, one tries to help the others. May sound funny. I think I am not able to put the argument across properly.