Americans were already wary of artificial intelligence. Then tech titans proclaimed society could shortly collapse. Dario Amodei, chief executive of Anthropic, warned of cyberattacks, bioterrorism, a ravaged economy, and A.I. slipping beyond human control. But policy experts say such science fiction visions distract from nuanced conversations about governing tech companies and what responsibility their human leaders owe the public.

"A.I. destroying humanity is the worst possible way to kick off a conversation about the public policy of A.I.," said Milton Mueller, a professor at the Georgia Institute of Technology. "It completely diverts attention away from human agency."

Top executives have lobbied for rules they say make technologies safer. After an A.I. mishap this summer, Anthropic researcher Jacob Coxon resigned, citing ignored safeguards. On Saturday, Dr. Amodei called for slowing A.I. development. Sam Altman of Open AI, Elon Musk of Space X, and Demis Hassabis of Google Deep Mind agreed. Washington is responding: the top Republican and Democrat in the House agreed Congress should act. President Trump dismissed calls to rein in A.I., but an unlikely group will discuss a "pro-human future with AI" on Tuesday, including Bernie Sanders and Steve Bannon.

Ivy Goode, 65, a tourist from Maryland, said the technology is already terrifying. "Only God himself can do the human extinction," she said. "But they've come in and just destroyed so much of what the creator created."

David Evan Harris of the University of California, Berkeley, said apocalyptic visions are vague. Colleen Chien, co-director of the Berkeley Center for Law & Technology, said A.I. agents need human help. "For a nuclear weapon or a virus to be released, there's a person at many gates," she said.