Into the void: validating a LIWC-based index of linguistic expressions of nihilism

Recently, law enforcement agencies have issued public warnings about online nihilistic violent extremist networks, such as ‘764’, that target vulnerable youth on mainstream platforms like Roblox. Using Linguistic Inquiry and Word Count (LIWC), a computerized text-analysis program that quantifies psychologically meaningful patterns in word use, the current study developed and validated a LIWC-based index of linguistic expressions of nihilism. The index combined nine standard LIWC categories that theoretically aligned with contemporary conceptualizations of existential nihilism. A nationally representative sample of US adults (N = 599) recruited through Prolific completed one of two self-narrative writing tasks (past-oriented versus future-oriented), followed by a series of counterbalanced self-report measures assessing existential nihilism endorsement, meaning in life (presence and search), depression, and suicidal ideation. Results indicated that the LIWC-based index showed modest evidence of construct and concurrent validity in relation to self-reported existential nihilism and theoretically relevant constructs. Individuals with the highest endorsement of existential nihilism used significantly more linguistic expressions of nihilism than those with the lowest endorsement. Although validity evidence was modest, these findings provide an initial linguistic measure of nihilism for future research assessing nihilistic language on violent extremist forums and closed or semi-private chat platforms, such as Discord.