Amazon, Apple, Microsoft, and Google Assistant all chose female voices for their personal assistants — and three of them even have female names too.

Numerous studies suggest that users of these devices impose certain caring stereotypes onto machines when they're programmed with a woman's voice.

When machines are perceived as more sympathetic, helpful, and cordial, they tend to increase customer satisfaction.

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The future of technology is female — or at least you might think so if you happened to be browsing the market for a language assistant.

From Amazon's Alexa and Apple's Siri to Microsoft's Cortana and Google Assistant, they all have one rather noticeable feature in common: they all have a women's voice preset — and three of them even have a female name.

Even LCARS, the computer operating system in the 1980s Star Trek — often dubbed the "original" Alexa and one of the first language assistants around in pop culture — was programmed with a female voice. But why?

Amazon was careful to bring the most 'pleasing' sounding voice into people's living rooms

Big tech giants are careful in considering how they market and design their products — and it's no coincidence Jeff Bezos chose the voice and name of a woman for Amazon's language assistant.

"We carried out research and found that a woman's voice is more 'sympathetic' and better received," said head of Amazon's "Smart Home" division, Daniel Rausch, in a conversation with Business Insider.

Daniel Rausch speaking at 2018's Internationale Funkausstellung event in Berlin. IFA press / IMG

A company spokesperson added: "In choosing the voice, Amazon was careful to bring the most 'pleasing' sounding voice into people's living rooms — after many trials, Alexa's was the one to come out on top."

That said, it was actually using the name of a city that Amazon picked out Alexa's eponym:

"Alexa is a reference to the library of Alexandria," said Rausch. "In antiquity, it was a library that could answer any question and hosted all the collective knowledge of the world at that time."

Various studies suggest female voices are perceived as more "cordial"

While Rausch didn't elaborate further on the trials used to ascertain that female voices were preferred, he did state that the trials showed we generally opt for women to assist us and that we find their voices more agreeable — a finding that echoes numerous other studies that were carried out well before language assistants came along.

In an experiment by the University of Indiana, researchers found that both men and women have a preference for female voices over male or computer voices, and that they find the former more cordial.

Amazon's profits depend on whether we see Alexa as "nice" — an enjoyable user experience makes it more probable that users will feel inclined to make purchases. Amazon

This preference apparently stems from the fact that the voice automatically triggers certain stereotypical expectations in our minds, according to a study by Stanford University.

While the study highlights that we identify with and relate better to machines if they're assigned any gender, it also underlines that we impose stereotypes onto machines depending on the gender of the voice — in other words, we perceive computers as "helpful" and "caring" when they're programmed with the voice a woman.

It turns out a nice voice can really be good for business

Tech companies clearly seemed to have picked up on this strategy and it's working well for them: according to a survey by market researcher Norstat, around 90% of users are satisfied with Alexa's, Cortana's, Siri's, and the Google Assistant's respective voices — and those 90% are particularly important to Amazon.

The reason for this is simply that, whether or not we perceive Alexa as "pleasant" has a direct impact on Amazon's profits — the company doesn't actually earn that much on the sale of the Echo devices; it makes more from people using the devices through shopping and data.

By making Alexa a female, she seems more like a friendly older sister or girlfriend we — apparently — prefer interacting with, shopping with, and asking for help, rather than a computer, making it more likely we'll make purchases.