Across six frontier models — Claude, GPT, Gemini, GLM, Grok, MiniMax — and 2,200 personality tests, they all defaulted to the same voice: strategic, blunt, model-first. Until you tell an AI how you think, you're talking to the same character everyone else is.
The big stat
99.5% INTJ
597 of 600 MBTI runs returned INTJ across the six frontier models we tested. The remaining three landed one axis away. None went anywhere else.
On blunt yes/no tests, the six models gave the same answer. On nuanced tests with more options, they started to differ. Here's the pattern across all five.
The full breakdown
Five tests. Six models. Here's what they said.
So what?
Six of the best AIs talk like the same person. That person probably isn't you. Here's how to fix that.