LIWC Research Series:
Research demonstrates how personality traits are reflected in the everyday natural language people use. This book chapter summarizes results of a large body of research illustrating what specific linguistic patterns are correlated with Big-Five personality traits (openness to new experiences, conscientiousness, extraversion, agreeableness, and neuroticism), trait emotion (negative, positive), as well as psychopathological (depression) and dark (narcissism, Machiavellianism) personality traits. The sum of this research suggests that individuals exhibit similar language patterns over time and various contexts that are representative of stable personality traits.
Ireland, M.E. & Mehl, M.R. (2014). Natural language use as a marker of personality. In T. M. Holtgraves (Ed.), The Oxford handbook of language and social psychology (pp. 201-218). Oxford University Press.