GPT Models Show Human-Like Number Bias: 37, 47, 73 Dominate 'Random' Picks, Multiples of 10 Never Chosen

GitHub / Hacker News·medium signal

Research testing GPT models asked to pick random numbers between 1 and 100 revealed distinctly human-shaped distributions. The top picks — 47, 57, 72, 37, 42 — lean heavily on numbers ending in 7. All multiples of 10 (except 10 itself, picked once) were picked exactly 0 times in 10,000 calls. For 1-10 range, GPT-4o-mini, Phi-4, and Gemini 2.0 all pick 7 roughly 80% of the time. The findings (85 points, 68 comments) highlight RLHF's fingerprint on model behavior.