Here is an excerpt:
Of course, just because a delusion has logical roots doesn’t mean it’s helpful for the person once it takes hold. Indeed, this is why delusions are an important clinical issue. Delusions are often conceptualised as sitting at the extreme end of a continuum of belief, but how can they be distinguished from other beliefs? If not irrationality, then what demarcates a delusion?
Delusions are fixed, unchanging in the face of contrary evidence, and not shared by the person’s peers. In light of the social function of beliefs, these preconditions have added significance. The coalitional model underlines that beliefs arising from adaptive cognitive processes should show some sensitivity to social context and enable successful social coordination. Delusions lack this social function and adaptability. Clinical psychologists have documented the fixity of delusional beliefs: they are more resistant to change than other types of belief, and are intensely preoccupying, regardless of the social context or interpersonal consequences. In both ‘The Yellow Wallpaper’ and the novel Don Quixote (1605-15) by Miguel de Cervantes, the protagonists’ beliefs about their surroundings are unchangeable and, if anything, become increasingly intense and disruptive. It is this inflexibility to social context, once they take hold, that sets delusions apart from other beliefs.
Across the field of mental health, research showing the importance of the social environment has spurred a great shift in the way that clinicians interact with patients. For example, research exposing the link between trauma and psychosis has resulted in more compassionate, person-centred approaches. The coalitional model of delusions can now contribute to this movement. It opens up promising new avenues of research, which integrate our fundamental social nature and the social function of belief formation. It can also deepen how people experiencing delusions are understood – instead of contributing to stigma by dismissing delusions as irrational, it considers the social conditions that gave rise to such intensely distressing beliefs.