All or Nothing Thinking
Cognitive Distortions are exaggerated or irrational thought patterns that are believed to perpetuate the effects of psychopathological states, especially depression and anxiety. When we over-rely on cognitive distortions, we usually interpret events in such a way that fuels emotions such as anxiety, depression, or anger. All-or-nothing thinking is one such distortion. All-or-nothing thinking refers to thinking in extremes. You are either a success or a failure.
(All-or-nothing thinking or dichotomous reasoning) Evaluating the self, as well as events in life in extreme terms. It’s either all good or all bad, either black or white, nothing in between. Causing every small imperfection to seem incredibly dangerous and painful. Splitting involves using terms like "always", "every" or "never" when this is neither true nor equivalent to the truth. Example: When an admired person makes a minor mistake, the admiration is turned into contempt.
Narcissistic personality disorder
People matching the diagnostic criteria for narcissistic personality disorder also use splitting as a central Ego Defense Mechanism. Most often the narcissist does this as an attempt to stabilize their sense of self positivity in order to preserve their Self Esteem, by perceiving themselves as purely upright or admirable and others who do not conform to their will or values as purely wicked or contemptible. Given "the narcissist's perverse sense of entitlement and Splitting ... he or she can be equally geared, psychologically and practically, towards the promotion of projects simultaneously, promoting the demise of a certain collectively beneficial project.
The cognitive habit of splitting also implies the use of other related Ego Defense Mechanisms, namely idealization and devaluation, which are preventative attitudes or reactions to narcissistic rage and narcissistic injury.