Type D personality

Type D personality, a concept used in the field of medical psychology, is defined as the joint tendency towards negative affectivity (e.g. worry, irritability, gloom) and social inhibition (e.g. reticence and a lack of self-assurance).

[8][9][10][11] Consequently, some researchers have argued that these earlier, small (and therefore potentially statistically underpowered) studies that appeared to link Type D personality to mortality in CAD and CVD patients may have inadvertently reached exaggerated or false conclusions.

People who score 10 points or more on both dimensions are classified as Type D. Both negative affectivity and social inhibition have been shown to be relatively stable traits across four years.

Various researchers have criticised this two-group method, not only for resulting in less statistical power but also for risking spurious type D effects.

[17][18] A four-group method was commonly applied to solve this issue by distinguishing individuals without Type D personality from those with high scores on either negative affectivity or social inhibition alone.

[17][19] For instance, in some of these simulated data, only one personality trait (e.g., only negative affectivity) was causally related to an outcome.

The continuous interaction method does not classify individuals in personality groups, but includes the negative affectivity and social inhibition scores as predictors in the statistical model.