When compared to other marsupial, human beings are more pliable due to their physiological adaptations, which have resulted in the development of a wide range of abilities and a unique versatility in behavior. Through the first twelve years of a human's life, the brain's great size, intricacy and gradual development with neural conjunction results in learned behavior, which could greatly modify stereotyped instinctive responses. .
Due to unique capability for culture in the sense of conscious thinking and planning, transmission of skills and systems of social relationships, and creative modification of the environment, the human species has integrated patterns of different behavior. .
(Human Behavior, Encarta Encyclopedia a 1993-2002 Microsoft Corporation). .
The diverse cultures, environments and habitats one lives in proliferate different kinds of human behavior. As a result of evolution, environment and habitats modify thus, resulting in a change in human behavior. Human's brain which percepts all things play a vital role in a behavior of a certain person. For example, if the living environment of a boy or a girl is such where he/she is neglected, scolded often, abused or subjected to family violence, then there is a sure shot that that boy/girl will show similar behavior anywhere else such as school. The outcome of such behavior would be aggression and frustration and he/she will express their emotions by swearing, fidgeting, misbehaving with other fellow students and annoying the teachers. Hence, behavior has much to do with human psychology and it is this department of physiology that is not given much regard by scientists or researchers. .
Even in this era of great advancement, brain function discovery is not taken earnestly. Since the human brain is considered to be a very complex organ it cannot be fully comprehended in a short period of time but this does not at all imply that it is undiscoverable.