The main characteristics of the skeptically-prone personality (SPP) are:

They are nearly impossible to hypnotize;
As children they questioned the existence of Santa Claus and God;
As adults they continued to doubt the existence of Santa Claus and all forms of supernatural creatures;
As children they played make-believe games, but they recognized the difference between make-believe and reality;
As adults they do not spend more than 50% of their time fantasizing;
They rarely experience hypnagogic or hypnopompic hallucinations (waking dreams), including those involving monsters from outer space or figures from religious traditions);
They rarely pretend to be somebody they're not;
They are mistrustful of memory and consider vividness to be irrelevant to the accuracy of a memory
They are mistrustful of interpretations of sense experiences;
They have little faith in eyewitness testimony;
They can rarely have an orgasm just by using their imagination;
They are mistrustful of tradition and tend to think that the older some idea or practice is the less likely it is to be true or worth engaging in;
They think there is a naturalistic explanation for everything, even if we don't know what it is;
They think people who think they've had a paranormal experience are deluding themselves;
They rarely have out-of-body experiences;
They believe that once you're dead you're dead and can't talk anymore;
They don't engage in automatic writing, Ouija board games, or séances;
They don't believe in magical healing powers, but follow the advice of those promoting science-based medicine;
They trust the results of well-designed controlled studies over beliefs based solely on personal experience;
They haven't experienced spirits or ghosts (see 13);
They tend to dislike intensely those who lie, defraud others, or promote self-serving nonsense as if it were infallible truth;
They don't feel handicapped by their skepticism; on the contrary, they feel empowered by their devotion to reason, logic, critical thinking, empirical evidence, and science;
They don't like lists, unless backed by scientific studies and footnotes *, and they're fond of concepts like the fantasy-prone personality and cognitive dissonance.