This is Scientific American's 60 Second Science.

I'm Christopher Intagiyata.

If you've ever used a digital assistant like Siri or Alexa,

you know the back and forth doesn't quite have the same rhythm as real human to human conversation.

The pauses are just a little too long.

We feel this sort of awkward silence building up.

Sebastian Lote, a research psychologist at the University of Beelifield in Germany.

If I ask you something and you just don't respond, it feels like, oh my God, this silence is almost

killing the room and you can feel it literally building up so we try to avoid that and that's the kind of effect that you're seeing with

Siri taking a second to respond you're feeling odd about it.

To study how humans are able to have such fluent sometimes to

to study how humans are able to have such fluent, sometimes even overlapping

conversations,

Lotonous team set up what's called a ghost in the machine

experiment in a bar room situation. Real human customers bellied up to a bar where a robot

bartender was waiting. The robot was actually controlled by human operators behind

the scenes who could see and hear the customers through the robot's eyes and ears.

Then Lothan's team observed how the human operators behaved during a couple hundred orders.

They found that when the customers started a phrase with what?

The human operators quickly triggered the robot to repeat the

offerings of the bar, like we have Coke, orange juice, and water, rather than waiting for customers

to complete the sentence. But if the customers began a sentence with I'd like or I want the human operators

...