Marissa Mayer: Anyone who says they know how AI will play out is ‘either lying or arrogant or both’

Marissa Mayer has been a builder in Silicon Valley since the dawn of Google.

But even she says the honest answer about where AI is headed is that nobody knows.

“We have a new form of intelligence, and anyone who says they know how this is going to play out is either lying or arrogant or both,” Mayer told Fortune executive editorial director Diane Brady on stage at the annual Most Powerful Women Summit in California, when asked about the debate raging over the frontier AI labs.

The uncertainty cuts both ways, said Mayer.

“We have to acknowledge that there is a possibility that things won’t go well,” she said.

But Mayer put the odds of a negative outcome at “well less than 50%,” noting that even some AI doomers would agree with her.

“What that really means is the odds are in our favor,” she said, pointing to potential medical and science breakthroughs and “freeing people up to spend their time and live their lives the way they want to.” She admitted to being an optimist, but welcomed discussions about regulation and collaborations across frontier labs as they advance.

She also acknowledged, in responding to a question from Brady, that public sentiment in the U.S. has turned against AI, and she said the industry probably bears some of the blame.

The early positioning of the technology was “perhaps too cavalier,” she said, leaving people to question what the enterprise-level embrace of AI will mean for jobs, families, and children’s futures.

“I personally think it can make all three of those things better,” she told Brady.

From Yahoo to Dazzle Mayer has had a long run at the top of tech, joining Google as an early engineer and becoming one of its most high-profile executives before taking over Yahoo as CEO in 2012, becoming the youngest woman to be a CEO in the Fortune 500 at the time.

Accordingly, her tenure drew an intense spotlight, including her decision to take a short maternity leave.

Looking back, Mayer said people missed the context.

“Yahoo couldn’t afford to have a CEO who was out for three or six months,” she said.