What word sums up humanity more than any other? Apparently, it's "poop".

That's right. When volunteers were asked to decide whether the responder was a machine or a fellow human based on a single word, those who picked the word "poop" were considered to be the most convincing humans. (It's 2018 and the world seems to be going to s***, so perhaps this is entirely fitting.) 

Cognitive scientists from the Department of Brain and Cognitive Science at MIT recruited volunteers to take part in a “minimal Turing test”, a variation of the original devised by Alan Turing in 1950 to determine whether or not an artificially intelligent being can display intelligent behavior equivalent to a human. In this particular iteration of the test, volunteers had just one word to convince an independent judge of their humanity. The results have been published in the Journal of Experimental Psychology.

Around 1,000 participants took part, providing the researchers with ideas for the one word they would pick. Perhaps unsurprisingly, many exploited the one thing that distinguishes us from machines more than any other – emotions. Forty-seven percent selected a word the researchers categorized as “mind perception”, which means any word related to emotions or the thinking process. Love was the most popular with 14 percent of the overall vote. (Aren't we a romantic lot?) In second and third place were the words "compassion" (3.5 percent) and “human” (3.2 percent) respectively. 

There were nine further categories, including non-humans (like "penguin" and "kitten"), food (like" pizza" and "pudding"), and bodily functions and profanity (like "penis" and "diarrhea"). Credit for the most imaginative choices goes to whoever came up with the words "bootylicious", "onomatopoeia", and "doh".

But that wasn't all. In the next stage of the experiment, the researchers paired the most popular word from each category at random – for example, "banana" and "please". A new set of volunteers (2,405 people in total) then had to judge which of the two words had been chosen by a human and which had been chosen by a machine. (Yes, the researchers weren't being entirely honest here. Both choices had been chosen by a human but that was the whole point of the experiment.)

What did they find? For starters, if you are ever in a dystopic nightmare and are asked to complete the minimal Turing test to prove your humanity, do not choose the word "robot". It was voted the least convincing. "Love", "please", and "mercy" all did fairly well, but the most effective word tested was "poop". 

The researchers only tested the most popular words and it would be interesting to see how more original words like "supercalifragilisticexpialidocious" and "swagger" would fare in the thought experiment. But the study authors suggest the results imply ruder, more "taboo" words that provoke amused reactions could mark us out as human more than less controversial words like "banana" and "alive".