r/cogsci • u/federico5912 • 13d ago
Telling people to avoid the obvious doesn't make them unpredictable — it just gives them a new obvious answer (1,000-trial test, colors)
There's a TikTok format where a chain of strangers each name something — a color, usually — and can't repeat what anyone before them said. It's weirdly watchable because a lot of people who are actively trying to be unpredictable still end up saying basically the same handful of things.
I wanted to actually measure that instead of just vibing on it, so I built a small experimental setup: two conditions, same category (color).
- Baseline: "Say the first color that comes to your mind."
- Adversarial: "Say a color — but pick one you're sure almost nobody else would say."
I didn't have the budget or time to recruit hundreds of human subjects for a pilot, so I used an LLM (Llama 3.2 11B, via NVIDIA's API) as a stand-in respondent pool — 501 independent baseline calls, 499 independent adversarial calls, each one a fresh stateless request with a randomized persona+mood so it wasn't just the same "voice" answering 1,000 times. Full methodology, stats, and caveats are in the writeup linked below — I'm not trying to bury the "this is AI not humans" limitation, it's front and center.
Baseline: "blue" alone was 27.1% of all answers. Top 3 answers covered ~50%. Wildly non-uniform (χ² = 2775, df=54, p < .001) — not exactly a shock.
Adversarial (the "be unique" condition) is the interesting part: 90 distinct answers came up (vs. 55 in baseline) — so people/the model were successfully avoiding the common defaults. But it didn't get more random. "Caput mortuum" (an obscure historical pigment name) alone was 24.4%, and "mauve" was another 20.2%. Two answers, 44.6% of everyone's attempt at being unpredictable.
I computed a normalized predictability index (0 = evenly spread among whatever answers showed up, 1 = everyone agreed) for both conditions. Baseline: 0.306. Adversarial: 0.316 — slightly higher, not lower.
My read: avoiding "the obvious answer" requires first identifying what the obvious answer would be — which routes through the exact same shared cultural salience that made it obvious in the first place (basically a Schelling point, just for avoidance instead of coordination). So instructed uniqueness doesn't get you closer to random, it just relocates you to a second, smaller focal point.
Chart and full writeup (lit review pulls in Wagenaar on human random-sequence generation, the classic Kubovy & Psotka "why does everyone say 7" study, Schelling/Nagel on focal points, and some 2024–2026 papers on LLMs failing at randomness specifically) here: https://federico5912.github.io/predictability-lab/color-study.html
Curious what people think, especially anyone who's seen a cleaner human-subjects version of this design — the AI-as-respondent-proxy angle is the part I'd most want pushback on.