Facebook abandoned an experiment after two artificially intelligent programs appeared to be chatting to each other in a strange language only they understood.

The bizarre discussions came as Facebook challenged its chatbots to try and negotiate with each other over a trade, attempting to swap hats, balls and books, each of which were given a certain value. But they quickly broke down as the robots appeared to chant at each other in a language that they each understood but which appears mostly incomprehensible to humans.

The robots had been instructed to work out how to negotiate between themselves, and improve their bartering as they went along. But they were not told to use comprehensible English, allowing them to create their own "shorthand", according to researchers.But there appear to be some rules to the speech. The way the chatbots keep stressing their own name appears to a part of their negotiations, not simply a glitch in the way the messages are read out.

Indeed, some of the negotiations that were carried out in this bizarre language even ended up successfully concluding their negotiations, while conducting them entirely in the bizarre language. They might have formed as a kind of shorthand, allowing them to talk more effectively.

“Agents will drift off understandable language and invent codewords for themselves,” Facebook Artificial Intelligence Research division's visiting researcher Dhruv Batra said. “Like if I say ‘the' five times, you interpret that to mean I want five copies of this item. This isn't so different from the way communities of humans create shorthands.”

That said, it's unlikely that the language is a precursor to new forms of human speech, according to linguist Mark Liberman."In the first place, it's entirely text-based, while human languages are all basically spoken (or gestured), with text being an artificial overlay," he wrote on his blog. "And beyond that, it's unclear that this process yields a system with the kind of word, phrase, and sentence structures characteristic of human languages."

The company chose to shut down the chats because "our interest was having bots who could talk to people", researcher Mike Lewis told FastCo.
(Researchers did not shut down the programs because they were afraid of the results or had panicked, as has been suggested elsewhere, but because they were looking for them to behave differently.)

The chatbots also learned to negotiate in ways that seem very human. They would, for instance, pretend to be very interested in one specific item – so that they could later pretend they were making a big sacrifice in giving it up, according to a paper published by FAIR.

Facebook's experiment isn't the only time that artificial intelligence has invented new forms of language.

Earlier this year, Google revealed that the AI it uses for its Translate tool had created its own language, which it would translate things into and then out of. But the company was happy with that development and allowed it to continue.

Another study at OpenAI found that artificial intelligence could be encouraged to create a language, making itself more efficient and better at communicating as it did so.

Update: This article has been amended to stress that the experiment was abandoned because the programs were not doing the work required, not because they were afraid of the results, as has been reported elsewhere.