Sixty years of linguistic change in the poetry of a Zen practitioner: a longitudinal case study of Gary Snyder.

Can decades of Zen meditation leave measurable traces in the practitioner's natural language? Long-term contemplative practice is widely understood to reshape emotion regulation, self-referential processing, and perceptual engagement, yet empirical research on these transformations has been fundamentally constrained by two limitations: an observation window of weeks to months at most, and an almost exclusive reliance on self-report and neuroimaging measures that cannot reach the automated, prereflective dimensions of psychological life most directly reshaped by sustained practice. This study applies computational quantitative content analysis to nine major poetry collections by the American Zen practitioner-poet Gary Snyder, spanning six decades (1959-2015), to test three directional hypotheses derived from core Zen concepts: affective settling (ānxīn, H1), self-referential attenuation (anātman, H2), and perceptual despecification (ānimitta, H3). Each hypothesis is held against a rival explanation as a falsification reference. The results reveal career-long changes across three analytical domains: negative-emotion vocabulary declines monotonically while positive and neutral categories show no statistically detectable trend; first-person pronouns, somatic vocabulary, grammatical agency, and cognitive certainty converge in decline across four distinct linguistic layers; embodied sensory specificity thins systematically while vocabulary drifts toward greater abstraction. Changepoint detection offers descriptive corroboration of the periodization. A comparison with a contemporaneous non-practicing poet (Wendell Berry) is descriptive in evidential status: the affective and self-referential trends are significant in Snyder but not in Berry, direct tests of the between-poet differences do not yield differences that are robust across interval-construction methods, and sensory thinning appears in both poets and may reflect processes shared across long poetic careers. These findings constitute what is, to our knowledge, the longest longitudinal linguistic record of a verified long-term Zen practitioner-documenting career-long changes that are consistent with, though not attributable to, sustained practice-and demonstrate the distinctive methodological value of naturally produced creative texts as a comparatively non-reactive observational window for studying long-term contemplative transformation.