From Research Digest:
Participants who scored higher in extraversion tended to describe the photos in terms that were rated by an independent coder as more abstract. For example, they used more “state verbs” (e.g. Jack loves Sue) and adjectives, and they admitted to engaging in more interpretation – describing things that were not directly visible in the pictures. On the other hand, the higher a person scored in introversion, the more concrete and precise their speech tended to be, including more use of articles (i.e. “a”, “the”), more mentions of numbers and specific people, and making more distinctions (i.e. use of words like “but” and “except”).
The differences make sense in terms of what we know about social behaviour and the introvert-extravert personality dimension, with the introverted linguistic style being more cautious, and the extravert style being more casual and vague.
The researchers said their results have far-reaching implications because we know based on past research that the contrasting speech styles are interpreted differently. For instance, they said behaviour described in abstract terms, in the style of an extravert (e.g. Camiel is unfriendly), is usually attributed to personality, as opposed to the situation, and therefore interpreted as enduring, more likely to occur again, yet harder to verify. By contrast, behaviour described in more concrete terms, in the characteristic style of an introvert (e.g. Camiel yells at Martin), tends to be interpreted as situation-specific, and as more believable.
“Thus an introvert’s linguistic style would induce more situational attributions and a higher perception of trustworthiness than an extravert’s style,” the researchers said.