Where does personalty come from?

Nature, nurture, 
neither – or both?

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Your personality is unique, but where does it come from? Were you born with it? Or was it etched onto a blank slate by your experiences and your environment?

This is the old nature-versus-nurture debate, also known as “heredity-versus-environment,” and it’s not the kind of question that can be answered with certainty. However, heredity is appearing to have a much greater influence on personality and behavior than once thought.

Just a few decades ago, the prevailing belief among psychologists was that the environment was the cause of all behaviors. But today, evidence suggests that approximately “40 to 50% of the variation in most personality traits has been shown to be caused by genetic influence, with a very small amount of the variation caused by shared environment.” (1,2)

Does this mean that biology is destiny?
No – and history has left us with a horrifying legacy of how terribly people can suffer when those who would misuse and abuse have the power to do so.

To the contrary, it means that just as we are not surprised when two blue-eyed parents produce a blue-eyed infant, we should be open to the possibility that personality variables such as affect (mood) might also have a genetic basis. For example, when two people who never seem to be content and complain constantly produce a child who behaves similarly, shared environment may be only part of the reason. Inherited tendencies in temperament may also be involved.

How nature-versus-nurture is studied
Heredity-versus-environment is most commonly researched using:
– Twin studies,
– Adoption studies,
– DNA analysis combined with trait association studies.

Relevance for the workplace
Aside from being interesting on its own, connections between personality variables and work have implications for the ways in which individuals experience their jobs and their work, how individuals work together in groups, and the influence of personality on outcomes, such as job performance, that may be important to organizations.

See also:
▪ Personality and heart disease: Goodbye 'Type A:' Hello 'Type D'
▪ Self-efficacy: The little personality variable that could
▪ Negative affect: Harder to 'be around' or harder to 'be'

Source Material

1. Dilalla, L. 2004. In Dilalla, L. Behavior Genetics Principles: Perspectives in Development, Personality, and Psychopathology. Washington, D.C.: American Psychological Association.
2. Plomin, R., Happe, F., & Caspi, A. (2002). Personality and cognitive abilities, In P. McGuffin, J.J. Owen, & I.I. Gottesman (eds.), Psychiatric genetics and genomics. (pp.77-112). Oxford, UK: Oxford University Press.