[3] Grandiosity is also measured as part of other tests, including the Specific Psychotic Experiences Questionnaire (SPEQ), Personality Assessment for DSM-5 (PID-5), Psychopathy Checklist-Revised, and diagnostic interviews for bipolar disorders and NPD.
The presentation varies across disorder type, but generally manifests as extreme self-confidence associated with a bold, proactive pursuit of certain (often unrealistic) goals, including writing a book, publicity-seeking over ideas or inventions devised without appropriate knowledge, experience or expertise, or taking major risks (e.g., in business or with finances) on the assumption that one cannot fail.
[2] In bipolar type 1, grandiosity can transition into full-blown delusions of grandeur (e.g., being a famous intellectual; having a special relationship with important world figures), often associated with other mood-congruent psychotic features.
Recently, an experimental study found that having participants engage in overly-positive rumination (i.e. think about times when they felt special, unique, important or superior) lead to increases in state grandiosity, whereas a control distraction condition conferred no such increment.
[8] Another study confirmed that positive ruminations confer grandiose self-perceptions in the moment, and found that (grandiosity-prone) patients with bipolar disorder (compared with healthy controls) exhibited heightened connectivity between brain regions associated with self-relevant information-processing during this task (medial prefrontal and anterior cingulate cortices)[9] Further, experimental studies suggest that grandiose narcissists maintain their inflated self-esteem following criticism by recalling self-aggrandizing memories.
A common characteristic of disorders and traits associated with grandiosity is heightened positive affect and potential dysregulation thereof.
Grandiosity demonstrates moderate-to-strong positive correlations with self-esteem, typically becoming larger in size when controlling for confounding variables.
[3] It is also associated with a host of other variables (often even when controlling for self-esteem), including positive affect, optimism, life satisfaction, behavioural activation system functioning, and all forms of emotional resilience.
[27][28][29] Grandiosity has a well-studied association with aggression (both physical and verbal), risk-taking (e.g. financial, social, sexual) and competitiveness.