Final answer:
Borderline Personality Disorder (BPD) is characterized by the defense mechanism known as splitting, where people perceive things as all good or all bad.
Step-by-step explanation:
The personality disorder that identifies splitting as the primary defense or coping style is Borderline Personality Disorder (BPD). Splitting is a defense mechanism where individuals view things in extremes—either all good or all bad, without any middle ground. This is often a response to complex situations or emotions that the person cannot integrate into their cohesive sense of self. People with BPD tend to experience intense emotions and have difficulty maintaining stable relationships because they can rapidly oscillate between idealizing and devaluing others. This phenomenon is also associated with an increased risk for self-harm and impulsive behaviors.
Psychological studies, such as those done by Joyce et al. (2003), highlight the interplay between temperament, childhood environment, and the subsequent development of personality disorders like BPD. Moreover, family studies, as reviewed by White et al. (2003), contribute to understanding the complex familial patterns associated with the disorder. The challenge of diagnosing and classifying personality disorders, reflected in the evolving editions of the DSM, underscores the need for ongoing research and nuanced understanding of disorders like BPD.