In one set-up, the participants were completely naive – they had not been told they might be speaking to a robot. As Milgram might have predicted, they were still clueless, even after lengthy conversations. “The vast majority of participants never picked up that they were speaking to the words of the computer program. They just assumed the person had some problem, where there social inhibitions had been diminished. Never for a minute did they think they were talking to a hybrid,” says Corti.

Science fiction – including the recent TV series Humans – has long questioned whether robots could one day integrate in our society, to the point we no longer make a distinction between who is alive and who is electronic; Corti’s experiments suggest that even with today’s limited AI, we are already more easily fooled than you would imagine.

There’s a catch, however. The team later tried to replicate the classic “Turing Test” of artificial intelligence. So in another condition, the participants were told that they may or may not be talking to a robot – and they had to guess which. Surprisingly, in this situation, the chatbot was no more likely to pass the Turing Test than if they had been chatting on a screen. “The bar is higher – people expect more,” says Gillespie.

It’s a kind of paradox: without being told that we might be speaking to an AI, we simply assume that our conversation partner lies in the stranger part of the spectrum of human behaviour. But as soon as we know that it might not be human, we are extra critical of its failings. “We might have AI’s intelligent beyond belief but our knowledge of them being non-human might limit our desire to interact with them in a human way,” says Corti.

Uncanny, or awkward?

Gillespie is particularly interested in the dilemmas that come with this kind of face-to-face encounter. “You can’t just walk away if eyes are looking at you,” says Gillespie. “There’s an obligation – and that’s why people feel awkward, whereas you would never feel awkward talking to a screen,” explains Gillespie.

I can relate to this. When I visited their labs and spoke to Sophia, she was very good at making the words flow naturally. Consider the following exchange:

Me: What’s in the news today?

Sophia: According to the BBC, the UK will vote on the EU, but not on 5 May.

M: OK. Now, why don’t you ask me a question?

S: Who is your favourite band?

M: I’m not really into bands but I do like songwriters like Joni Mitchell.

S: Joni Mitchell, sure, I like her a lot. She often stops by to say hello.

In fact, had we been talking online, I would have been fooled (though I might have assumed she was a confabulator). But face-to-face with her strange answers, any pause or hiccup became excruciating – in a way I wouldn’t have experienced, had we been chatting over instant messenger.