Taking Care of the Linguistic Features of Extraversion

Taking Care of the Linguistic Features of Extraversion Alastair J. Gill (agill@cogsci.ed.ac.uk) Division of Informatics, University of Edinburgh 2 Buccleuch Place, Edinburgh, EH8 9LW UK Jon Oberlander (J.Oberlander@ed.ac.uk) Division of Informatics, University of Edinburgh 2 Buccleuch Place, Edinburgh, EH8 9LW UK Abstract We study how Extraversion or Introversion influ- ences people’s language production. A corpus of e-mail texts was gathered from individuals cate- gorised via Eysenck’s EPQ-R personality test. One experiment analysed the corpus using existing con- tent analysis tools, and found relatively weak ef- fects of Extraversion. A second experiment used more sensitive bigram-based techniques from statis- tical natural language processing to replicate earlier findings, and uncover novel patterns of behaviour. Introduction Casual acquaintance with Extraverts 1 and Introverts suggests that the former talk a lot more than the latter. But apart from this intuitive diﬀerence, how does this personality dimension influence an individ- ual’s language production? Before addressing this question, we need to clarify what we mean by Ex- traversion, and its relevance to cognitive science. A typical Extravert tends to be sociable, needs people to talk to, craves excitement, takes chances, is easy-going, and optimistic. By contrast, a typical In- trovert is quiet, retiring, reserved, plans ahead, and dislikes excitement (Eysenck and Eysenck, 1991). The personality trait of Extraversion—and the complementary Introversion—is one of the few which researchers generally agree provides ‘consistent and valid information’ (Jonassen and Grabowski, 1993). Beyond it, there is greater controversy. For instance, Eysenck’s EPQ-R personality test reflects a personality model which incorporates just two further dimensions: Neuroticism, which is mainly characterised by susceptibility to anxiety; and Psychoticism, which is more complicated, but generally related to aggression and individuality. By contrast, the NEO-PI-R model incorporates five fac- tors (Costa and McCrae, 1992). As well as Extraver- sion and Neuroticism, there are Conscientiousness, Agreeableness and Openness. It is generally agreed that these relate to Psychoticism, but exactly how is The spelling of Extravert follows Eysenck, because this paper employs his EPQ-R as the measure of per- sonality, but this does not represent a commitment to a specifically Eysenckian theory of personality. still the subject of debate (cf. Matthews and Deary, Extraversion, and its linguistic consequences—if there are any—is relevant to cognitive research for at least two reasons. First, there is considerable evidence that this personality dimension is related to preferred learning styles and educational achieve- ment, via speed of exam completion, memory re- trieval and recall tasks, creativity, mathematical ability, self monitoring and communication ability (Jonassen and Grabowski, 1993). Secondly, there is evidence that computer users attribute personality to interfaces, and respond to it in robust ways (eg. Nass, Moon, Fogg, and Reeves, 1995; Isbister and Nass, 2000). Even in a text-only environment, Ex- traverts apparently prefer interfaces presenting in- formation using language associated with Extravert traits; Introverts prefer Introverted interfaces. An interface with a matching personality is judged more positively, and rated as more attractive, credible and informative (Nass et al., 1995). So the personality dimension has some validity, and appears relevant to the diagnosis and projec- tion of personality in human-computer communica- tion, and in computer-based learning. But how does Extraversion influence an individual’s language pro- duction? In addressing this question, we first outline some hypotheses from the literature, before describ- ing our collection of a controlled corpus of language, and our analysis of it. We then report the results— some unsurprising, others unexpected—and discuss some of their implications. Previous hypotheses Work on textual personality within the “Computers Are Social Actors” paradigm has taken the expres- sive hallmarks of Extraversion or dominance (one facet of the dimension) to be confidence, as shown by an avoidance of hedge-expressions such as per- haps and maybe (Nass et al., 1995), and is related to the empirical work of Bradac and Mulac (1984) on perceptions of powerful and powerless speech. From an intuitive perspective, Extraverts are de- scribed as individuals who think out loud, do most of the talking, are less self-focussed, and tend to skip from topic to topic. Conversely, Introverts mo-