It has been a long controversy about how nature and nurture imply to personality traits and human behavior. Nature means that genetic factor and the system of organs control the personality, while nurture means the personality is a result of conditioned circumstances where a person is brought up. It includes the personality of other people, like family, includes the teaching, and lessons a child gains during his/her mental development process. .
Recent studies find more in human biological system that genes are related to people's behavior. McInerney (2001) shows, many researchers believe that genetics factors determine how someone will act and think in his or her life. Animal and human are born with specific character linked with the genetic information in the genes. It shapes each individual trait exclusively including the performance in social, interaction, intelligence, and adaptability to the surrounding community.
Behavior may change, he states, as a person encounters "alterations in biological structures or processes", mechanically or chemically. For instance, a person's gentle personality may change dramatically after an accident that causes brain injury, therefore chemical treatment or medications - or even gene modification - is necessary to control the disorder and fix the problem. .
However, this cannot be concluded from one side view. Naturally there is none of the factor gives impact to personality change stronger than the other one. Psychologist Robert Plomin as cited by Azar (1997) says, both nature and nurture influence someone's personality, in other words, there is an equal portion of genetic factors and environmental factors in determining personality. The genetics factors only "give half of the variance of most traits", and environment takes the rest of it.
Human undergoes a certain change in adaptation to the environment. It is experiencing and focusing through feeling process.