[Paper Review] The ontogeny of discourse structure mimics the development of literature

Natália Bezerra Mota, Sylvia Pinheiro+5 more|Americanae (AECID Library)|Dec 27, 2016

Fractal and DNA sequence analysis18 references3 citations

TL;DR

This study reveals that the development of discourse structure in individuals mirrors the historical evolution of literature, using word graph analysis across 200 subjects (ages 2–58) and 676 literary texts spanning 5,000 years. It shows a monotonic, asymptotic increase in long-range recurrence and graph size with age and time, while short-range recurrence decreases, indicating a hierarchical maturation of discourse—blunted in psychosis and converging to adult-like structure during the Axial Age (800–200 BCE).

ABSTRACT

Discourse varies with age, education, psychiatric state and historical epoch, but the ontogenetic and cultural dynamics of discourse structure remain to be quantitatively characterized. To this end we investigated word graphs obtained from verbal reports of 200 subjects ages 2-58, and 676 literary texts spanning ~5,000 years. In healthy subjects, lexical diversity, graph size, and long-range recurrence departed from initial near-random levels through a monotonic asymptotic increase across ages, while short-range recurrence showed a corresponding decrease. These changes were explained by education and suggest a hierarchical development of discourse structure: short-range recurrence and lexical diversity stabilize after elementary school, but graph size and long-range recurrence only stabilize after high school. This gradual maturation was blurred in psychotic subjects, who maintained in adulthood a near-random structure. In literature, monotonic asymptotic changes over time were remarkable: While lexical diversity, long-range recurrence and graph size increased away from near-randomness, short-range recurrence declined, from above to below random levels. Bronze Age texts are structurally similar to childish or psychotic discourses, but subsequent texts converge abruptly to the healthy adult pattern around the onset of the Axial Age (800-200 BC), a period of pivotal cultural change. Thus, individually as well as historically, discourse maturation increases the range of word recurrence away from randomness.

Motivation & Objective

• To quantitatively characterize the ontogenetic and cultural dynamics of discourse structure across the lifespan and historical epochs.
• To investigate whether the structural development of discourse in healthy individuals parallels the historical evolution of literature.
• To examine how psychiatric conditions like psychosis disrupt the normal maturation of discourse structure.
• To identify key structural features—lexical diversity, recurrence patterns, and graph size—that define discourse maturity.
• To test the hypothesis that discourse structure evolves toward a stable, non-random, hierarchical organization over time and development.

Proposed method

• Constructed word graphs from verbal reports of 200 subjects across ages 2–58, using word co-occurrence and recurrence patterns.
• Analyzed literary texts from ~5,000 years of history, grouping them chronologically to track structural evolution.
• Quantified four discourse features: lexical diversity, graph size, short-range recurrence (local word repetition), and long-range recurrence (distant word repetition).
• Measured deviation from randomness in discourse structure using baseline models (e.g., random permutations of word sequences).
• Tracked developmental trajectories across age groups and historical periods to identify monotonic, asymptotic changes.
• Compared healthy individuals, psychotic adults, and literary texts to identify structural parallels between ontogeny and cultural history.

Experimental results

Research questions

• RQ1 How does discourse structure change across the human lifespan in healthy individuals?
• RQ2 Do the structural features of discourse in literature evolve in a manner analogous to individual development?
• RQ3 What is the role of education in shaping the maturation of discourse structure?
• RQ4 How does psychosis affect the developmental trajectory of discourse structure?
• RQ5 When and how did discourse structure converge to the adult-like pattern in human cultural history?

Key findings

• Lexical diversity, graph size, and long-range recurrence increased monotonically and asymptotically from childhood to adulthood, indicating progressive discourse maturation.
• Short-range recurrence decreased with age, suggesting a shift from local to global structural organization in discourse.
• The maturation of long-range recurrence and graph size only stabilized after high school, while short-range recurrence and lexical diversity stabilized earlier, after elementary school.
• Psychotic adults maintained a discourse structure near-random levels, indicating a failure to achieve mature discourse organization.
• Literary texts from the Bronze Age were structurally similar to childish or psychotic discourse, showing near-random patterns.
• Around the Axial Age (800–200 BCE), literary discourse abruptly converged to the mature, non-random adult structure, suggesting a cultural threshold in discourse complexity.