Mirror Particle is building a ‘world model’ of human behavior

What changed

Startups that promise to predict how humans will behave are having a moment. Over the past year, Simile raised $200 million at a $2 billion valuation; Aaru raised $88 million at a $1 billion valuation; and Humans&, an AI startup that announced a massive $480 million seed round in January at a $4.48 billion valuation, launched Persimmon to model human behavior. The status quo for human behavior prediction today relies heavily on large language models (LLMs) that are prompted or fine-tuned to role-play as a target demographic.

Why it matters

A concrete addition to Practical AI: Tools, Models & Frameworks: it changes what's available to builders today rather than being general commentary.

How it compares

Related prior coverage to compare against:

• Introducing Real World VoiceEQ: Measuring the human quality of voice AI
• Predicting model behavior before release by simulating deployment
• Improving language model behavior by training on a curated dataset

• Introducing Real World VoiceEQ: Measuring the human quality of voice AI similarity 0.16
• Predicting model behavior before release by simulating deployment similarity 0.16
• Improving language model behavior by training on a curated dataset similarity 0.13