What do highly narcissistic people think and feel about (their) intelligence? 
The current research comprehensively examined how grandiose and vulnerable narcissism are linked to intelligence and intelligence-related beliefs and emotions.  In four studies (total N = 1,141), we tested the associations between both forms of narcissism, subjectively and objectively assessed intelligence, basic personality traits, test-related stress, beliefs about intelligence, and well-being.  Both forms of narcissism (grandiose and vulnerable) were unrelated to objective intelligence.  Grandiose narcissism was associated with high self-perceived intelligence (Studies 1-3) and explained more variance in self-perceived intelligence than objective intelligence and the Big Five personality traits.  It was correlated with reduced distress in the context of IQ testing and low engagement in cognitive performance (Study 2).  Individuals with high grandiose narcissism based their well-being (Study 3) partly on intelligence and considered intelligence important for success in different life domains, especially for social relations (Study 4).  Vulnerable narcissism was unrelated to self-perceived intelligence (Studies 1-3) and went along with increased distress in the context of IQ testing (Study 2).  The results indicate that the topic of intelligence is of key importance for people with high grandiose narcissism psychological functioning and it also has some relevance for individuals with high vulnerable narcissism.