Final answer:
The key features for diagnosing schizotypal personality disorder are eccentric behavior, odd beliefs, and quirky speech, aligning with DSM criteria. Such individuals may display traits that resemble high psychoticism, including nonconformity and unusual perceptual experiences.
Step-by-step explanation:
The key features associated with the diagnosis of schizotypal personality disorder are eccentric behaviors, odd beliefs or magical thinking, and quirky manners of speaking or dressing. Unlike other options mentioned, these symptoms align with the clinical criteria for schizotypal personality disorder as per diagnostic manuals, such as the DSM or ICD.
Indeed, according to the American Psychological Association's Diagnostic and Statistical Manual on Mental Disorders (DSM), individuals with schizotypal personality disorder exhibit a range of peculiar behaviors and thoughts, which may include superstitious beliefs, unusual perceptual experiences, and odd speech patterns that can make it hard for them to establish relationships.
Moreover, referencing Eysenck's theory, those high on psychoticism may exhibit traits such as independence and nonconformity, which can be seen in schizotypal personality disorder, though this dimension is not as diagnostic as the specific symptoms listed in the DSM.