The imposters among us: function vectors that ace every check and do the wrong task (in search of circularity)

TL;DR: We extracted shift-by-k-months function vectors on Llama-3.2-3B from few-shot prompts that contained fewer distinct months (lower diversity). The vectors passed three classic checks: the behavioral gate, stability when extracting from disjoint halves of the prompt samples (cosine similarity ≥ 0.99 for the broken vectors, 0.98 for the full set), and the causal effect (where injection tripled zero-shot accuracy and the correct answer’s probability, including for the most broken vector).Howe...