What is Conscientiousness?

Brent W. Roberts at University of Illinois, Urbana-Champaign has a nice page summarizing the concept of conscientiousness. Roberts mentions interesting challenges in this field of study, and even talks about the effect behaviors associated with conscientiousness have on the fate of nations.

What is Conscientiousness?
Conscientiousness refers to individual differences in the propensity to follow socially prescribed norms for impulse control, to be task- and goal-directed, to be planful, delay gratification, and follow norms and rules (John & Srivastava, 1999).  As can be seen by the definition, conscientiousness is not really a single, unitary entity.  Rather, it is better thought of as a conglomeration of more specific traits and trait domains.
Our research on the lower-order structure of conscientiousness has revealed at least 5 replicable facets of conscientiousness:
1.  Orderliness:  The propensity to be organized and neat versus messy and disorganized.
2.  Self-control:  The propensity to inhibit prepotent responses.
3.  Industriousness: The propensity to work hard
4.  Responsibility: The propensity to be reliable, especially in social situations
5.  Traditionality: The propensity to follow socially proscribed norms and traditions
We have done several studies to investigate the underlying structure of conscientiousness and each of these studies has revealed specific facets that have not replicated.
1.  Decisiveness: The willingness to make a decision and to be firm in one's commitments
2.  Punctuality: The propensity to show up on time to appointments
3.  Formality: The propensity to follow the rules of social decorum
3.  Virtue: The propensity to be honest and to tell the truth
These remaining facets should be considered preliminary and await further replication.
Why is Conscientiousness Interesting?
Conscientiousness is interesting for many reasons. As a trait domain conscientiousness shows an interesting association with age--it goes up.  Not only does it go up, but it does so well into middle and old age (Roberts, Walton, & Viechtbauer, 2006).  This pattern is conspicuous for several reasons.  First, most developmental theories assume personality traits stop changing some time in childhood or adolescence.  The most charitable theories propose that traits continue to develop through young adulthood.  The fact that conscientiousness continues to develop well past young adulthood contradicts established scientific assumptions.  It is also something of a mystery.  Why would people continue to increase on conscientiousness in middle and old age?  What purpose do these changes serve?
Conscientiousness is also interesting because as a trait domain it represents one of the key psychological fulcrums between the individual and society.  Many societies spend inordinate time and energy attempting to make their citizens more conscientious. People are punished and rewarded in order to facilitate greater conscientiousness. Also, people who are more conscientious tend to grease the skids of social intercourse and social functioning--they make society work better for others by simply being conscientious. There is no more compelling personality trait domain for studying the interface between the individual and society.

h/t Dennis Mangan