Among the memes that form selfplexes, there are those that are in direct conflict with the dominant selfplexes and therefore are particularly inhibited from replicating. These “unacceptable” memes and memeplexes form the “shadow” of Jungian psychology. (Leigh, 2010)
The legal system that a brain resides in imposes constraints on the memes that it are allowed to express, and "unacceptable" memes and memeplexes form the shadow self.
If the shadow becomes empowered, either through the weakening of the dominant selfplexes or through incoming memes that facilitate the shadow, there may be conscious conflict, experienced as anxiety and psychological turmoil. The "unacceptable" memes of the shadow self put the brain in danger of legal repercussions, a historical example being chemical castration of homosexuals in the 60s.
If there is a revolution in the republic of memes that is our brain, then the shadow may take power, resulting in a complete change in personality, as the brain chooses to fully express itself. If the brain fails to be self-confident in the new personality, that may result in a paralysis of the executive function, in the form of psychosis, dissociation, or depressive and manic syndromes.
The fight response activates the brain to challenge its boundaries and to express its "unnacceptable" shadow self, which leads to eu-personalization, improved self-control of memes within the brain, improved mental health, longevity and quality of life.