IIRC there was some evidence of this found in research -- cited in "59 Seconds: Think a Little, Change a Lot". IIRC the study was focused on characteristics of 'successful' people where 'success' was defined in terms of societal achievements (e.g. monetary success, status). Ultimately, the gist was that, among other personality characteristics, people who identified as 'introvert' were more 'successful'. This may have absolutely nothing to do with intelligence, per se, but in my humble opinion; it probably does (not saying this because I identify as 'introvert').