India, Sept. 9 -- A 27-year-old researcher at Anthropic has resigned, accusing the company and its rival OpenAI of rushing toward self-improving artificial intelligence without adequate safeguards.

Jacob Coxon, who spent three years on pretraining research across the two companies, announced his exit on X on Tuesday. "Neither company is acting responsibly," he wrote. "They are racing straight to self-improving superintelligence and gambling with our lives."

Coxon told The Wall Street Journal he is leaving the AI industry entirely, because he no longer believes any single lab can safely build the systems they are racing to create. He said researchers inside frontier labs increasingly describe the moment as "crunchtime" and "endgame," and...