Do New Words Propagate like Memes? An Internet Usage-Based Two-Stage Model of the Life Cycle of Neologisms

Neologisms reflect new ideas or new concepts in our life and play an important role in cultural transmission and the vitality of human language. The explosion of neologisms, especially in the past two decades, can also be ascribed to the popularity and accessibility of digital content and social media. In this paper, we focus on the issue of how neologisms arise by looking at the trajectory of developments in terms of their usage over time, i.e., their life cycle. By studying neologisms in vivo, instead of as fait accompli, we hope to better understand the nature of neologisms and to enable better prediction and earlier inclusion of neologisms. To achieve this goal, we examine the memetic model for the life cycle of neologisms and compare it with a recently studied epidemic model. We present a longitudinal modeling of the development of neologisms based on internet usage data aggregated from Google Trends, covering the 90 most influential Chinese neologisms from 2008–2016. Our study verifies that the memetic model can describe and predict the life cycle of the neologisms robustly for the early stages (i.e., the ascending stages) of its cycle, but not for its full life cycle, and crucially cannot predict the inflection point. We conclude that two models are needed for word propagation: a memetic model for the initial stages and an epidemic model for the latter stage, particularly the inflection point. This two-stage/two-model approach allows for neologisms to be more easily identified as potentially new words, as it is easier to write a program to automatically filter for emerging terms using a memetic model.