This study examines the principles underlying ordinal linguistic personification (OLP): the involuntary and automatic tendency in certain individuals to attribute animate-like qualities such as personality and gender to sequential linguistic units (e.g., letters, numerals, days, months). This article aims to provide four types of evidence that OLP constitutes a form of synesthesia and is likely to have the same neurodevelopmental basis. We show that (a) OLP significantly co-occurs with other variants of synesthesia, (b) OLP associations (like those of synesthesia) are highly consistent over time (Experiment 1), (c) OLP associations (like those of synesthesia) have the characteristic of letter-to-word transference (i.e., they spread from initial letters throughout words) (Experiment 2), and (d) OLP associations (like those of synesthesia) are automatically generated and interfere in Stroop-type tasks (Experiment 3). We argue that these shared characteristics suggest a unified underlying behavior, and propose OLP as a subtype of synesthesia. In so doing, our study extends the range of reported phenomena that are known to be susceptible to cross-modal association.