"Creative people tend to be both extroverted and introverted. We're usually one or the other, either preferring to be in the thick of crowds or sitting on the sidelines and observing the passing show. In fact, in psychological research, extroversion and introversion are considered the most stable personality traits that differentiate people from each other and that can be reliability measured. Creative individuals, on the other hand, seem to exhibit both traits simultaneously." -- Mihaly Csikszentmihalyi, 1996-07-01 [by way of a 2011 Huffington Post article that quoted it, in turn by way of a Facebook friend who linked to that]
Also interesting (at least to me) from the same Psychology Today article: "Creative people, to an extent, escape rigid gender role stereotyping. [...] psychological androgyny is a much wider concept referring to a person's ability to be at the same time aggressive and nurturant, sensitive and rigid, dominant and submissive, regardless of gender. A psychologically androgynous person in effect doubles his or her repertoire of responses. Creative individuals are more likely to have not only the strengths of their own gender but those of the other one, too." (Yes, I picked up on the assumption that masculinity inherently equals aggressiveness and femininity inherently equals nurturing. OT1H the author did say "gender role stereotypin"; OTOH a lot of people seem to think that the stereotypes are the genders even now, and that was written in 1996, I don't know exactly which nuance fits here.)