We’re living in the age of the Fembot.

During an appearance on Jimmy Fallon this week, actress Salma Hayek recalls finding a text message from someone named “Elena” on her husband’s phone asking him if he wanted to practice his English with her. “I’m Mexican, you know, it doesn’t go well,” she says. “I was so furious, and I said, ‘Well, obviously she’s desperate’.” Turns out, that woman texting her husband — the billionaire businessman François-Henri Pinault– was a language app named Elsa.

Many of the apps and bots in your life are ladies — Apple’s Siri, Amazon’s Alexa, Microsoft’s Cortana, to name a new — and that’s no accident, experts say. For one, a female voices can seem more trustworthy than a male voices, studies show. And “as AI moves into more places in our lives and a diverse range of people are using the applications” trustworthiness is important, says Ben Arnold, an industry analyst with NPD Group. Plus, with so many people being paranoid about their devices spying on them this can make them seem safer to consumers.

There’s also research that shows that many consumers prefer a female voice to a male one. A 2011 study, in which men and women were played clips of male and female voices, showed that both genders thought women’s voices sounded warmer, and that women showed a subconscious preference for responding to a female voice.

“The research indicates there’s likely to be greater acceptance of female speech,” Karl MacDorman, an associate professor at Indiana University’s School of Informatics and Computing who specializes in human-computer interaction, told Wired in 2015. And this inclination “suggests that companies will make a better impression on a broader group of customers with a woman’s voice,” Wired concludes.

Some experts theorize that this also has to do with traditional gender roles: MacDorman told Live Science that it may be because these robots and other services perform traditionally female jobs like personal assistants.