Various researchers have criticised this two-group method, not only for resulting in less statistical power but also for risking spurious type D effects. 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.
This two-group method has been subject to criticism by various researchers, primarily due to its reduced statistical power and the risk of spurious Type D effects. A four-group approach was often employed as a solution, distinguishing between individuals without Type D personality and those with high scores on either negative affectivity or social inhibition.