Computer mediated communication (CMC) plays a rapidly growing role in our social lives. Within this domain, e-mail addresses represent the thinnest slice of information that people receive from one another. Using 599 e-mail addresses of young adults, their self-reported personality scores and the personality judgments of 100 independent observers, it was shown that personality impressions based solely on e-mail addresses were consensually shared by observers. Moreover, these impressions contained some degree of validity. This was true for neuroticism, openness, agreeableness, conscientiousness, and narcissism but not for extraversion. Level of accuracy was explained using lens model analyses: Lay observers made broad use of perceivable e-mail address features in their personality judgments, features were slightly valid and observers were sensitive to subtle differences in validity between cues. Altogether, even the thinnest slice of CMC—the mere e-mail address—contains valid information about the personality of its owner.
Source: “How extraverted is email@example.com? Inferring personality from e-mail addresses” from Journal of Research in Personality, Volume 42, Issue 4, August 2008, Pages 1116-1122