Splitting is a common defense mechanism, wherein the individual tends to think in extremes (e.g., an individual's actions and motivations are all good or all bad with no middle ground).

Splitting is observed in Cluster B personality disorders such as borderline personality disorder and narcissistic personality disorder, as well as schizophrenia and depression.

Individuals with borderline personality disorder (BPD) have even been shown to interpret social acceptance as subterfuge or deception. They have also been shown to be less sensitive to verbal irony due to a negative bias in interpreting ambiguous information. Individuals diagnosed with BPD may also believe that they will be abandoned if they trust anyone around them.

The individual will feel challenged by this discomfort as it relates to their self perception and will form a narrative to explain and externalize the perceived discomfort, making it wholly the fault of another. Proneness to rejection hypersensitivity, problems in establishing and maintaining consistent and appropriate levels of trust in interpersonal relationships, and frequent misinterpretation of social signals contribute greatly to a subject with BPD's ability to find supporting "evidence" for their devaluation process. This can be exacerbated in times of professional or personal stress as stress induced paranoia is a recognized diagnostic feature of BPD

The individual will then devalue the person that they once idealised. With people with Cluster B personality disorders, this often involves the embellishment or invention of grievances that garner an emotional response from those around them that they feel matches their own distress at the situation.

Splitting also impacts self-esteem, as the dichotomous good or bad thinking is applied to an individual's own self image and how they perceive themselves