Subdiffusive semantic evolution in Indo-European languages
This research addresses the fundamental question of semantic change in linguistics, providing a universal law that applies across multiple languages, though it is incremental in building on existing distributional semantic methods.
The study tackled the problem of how words change meaning over time by analyzing semantic evolution in five major Indo-European languages, finding that it follows strongly subdiffusive behavior with an anomalous diffusion exponent of α = 0.45 ± 0.05, contrasting with normal diffusion where α = 1.
How do words change their meaning? Although semantic evolution is driven by a variety of distinct factors, including linguistic, societal, and technological ones, we find that there is one law that holds universally across five major Indo-European languages: that semantic evolution is strongly subdiffusive. Using an automated pipeline of diachronic distributional semantic embedding that controls for underlying symmetries, we show that words follow stochastic trajectories in meaning space with an anomalous diffusion exponent $α= 0.45\pm 0.05$ across languages, in contrast with diffusing particles that follow $α=1$. Randomization methods indicate that preserving temporal correlations in semantic change directions is necessary to recover strongly subdiffusive behavior; however, correlations in change sizes play an important role too. We furthermore show that strong subdiffusion is a robust phenomenon under a wide variety of choices in data analysis and interpretation, such as the choice of fitting an ensemble average of displacements or averaging best-fit exponents of individual word trajectories.