One of Charles Darwin's last experiments - which seems more like a trick the evolutionist enjoyed playing on his dinner guests - has been re-born for the digital age.

The pioneer of the theory of evolution owned a collection of photographs showing a French man having his face contorted via electrical shock treatment into a range of grimaces.

So, sometime between dessert and a final drink in Darwin's home in 1868, Darwin would confront his poor dinner guests with the images and ask them to describe the man's expressions in their own words.

Darwin then collated the responses from the 24 guests who, instead of walking out or punching him on the nose, answered his questions, and used these 'crowd-sourced' answers to find the definitive description for each face.

Charles Darwin's last experiment: At the time, Darwin's friends suggested this expression was 'crying from grief' - modern day observers perhaps more accurately described this as 'confused'

Poor test subject: Here Darwin stimulated the 'corrugator supercillii', which caused the expression of 'suffering' to Darwin's audience - today, people said this was a mix of 'sad, concerned, and frantic' Galvanising the platysma and the frontal, depressed lower jaw, Darwin described this as terror - today's audience said it was 'fearful/surprise and horror'



Darwin was fascinated by the photos taken by French neurologist Duchenne de Boulogne, who referred to facial expressions as the 'gymnastics of the soul'. A DINNER DATE WITH DARWN

'Mr. Darwin brought in some photographs taken by a Frenchman, galvanizing certain muscles in an old man’s face, to see if we read aright the expression that putting such muscles in play should produce. It was curious the different meanings. And it came out at dinner, that several of us had been trying to move certain muscles before the [mirror] glass!'

- Jane Gray, wife of Harvard botanist Asa Gray, in a letter to her sister

He asked his guests to decide the best word to describe each picture, and then filtered through the results to find recurring themes. Darwin's big aim was to determine whether 'universal core emotions' exist, and whether they are modified through-out history and by language or culture. Now, the University of Cambridge’s Darwin Correspondence Project has repeated the experiment - but with the advantages of the Internet to lean on, the same questions have been answered by 18,000 people - a bit of a step up from Darwin's 24. The University said: 'Darwin was endlessly curious and we hope to provoke curiosity too. 'Are there core emotions? What are they and how many? Why do we express emotion in the way we do? How do we recognise it and can we be sure we all mean the same things? 'Is the expression of emotion innate? Or is it culturally modified? How do we equate different words to describe emotion (even in one language, let alone across different languages)? 'Can a static image ever convey emotion accurately? How do actors and artists convey it? These are all questions that Darwin was beginning to address and into which there is a great deal of current research.'

Darwin described this as 'agony, torture, and fright'. Today's audience described this as 'angry/shocked'

Discoloured with age, this image shows a 'frightened, agonised' expression - today's audience agreed this was a 'horrified/shocked' look The university added: 'One of the problems Darwin faced was whether to suggest possible responses to his participants or to allow them to use their own words. 'Just as Darwin chose to do, we accept any response, but Darwin only had to codify twenty-four responses. 'Our experiment will be on a much larger scale, so we use a compromise format developed by the Computer Lab to suggest possible answers drawn from their database, using a version of predictive text.' RELATED ARTICLES Previous

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Next Incredible video 'fly-over' by Nasa's Dawn probe reveals... Is it Mr Wrong or Mr Right? A woman's hormones may make her... Share this article Share Darwin selected the photographs from an original collection of seventy-three made by a French physiologist, Benjamin Amand Duchenne. Duchenne had set out to find the muscles responsible for creating particular expressions using an electrical device he had originally developed to investigate the muscles that control the hand. He applied galvanic probes to the facial muscles of a number of different test subjects. He also took what today could be thought of as control photographs of the same people with blank expressions, and others where they were attempting to simulate expressions without the aid of the probes. Here the photographer, Duchenne de Boulogne, makes an appearance as he lifts the eyebrows to create what both audience agree is a 'surprised' face

Finally a (forced?) smile: Darwin described this as 'laughter', modern viewers called it a 'happy'

While Darwin's 24 results may not give a great 'confidence' rating in his verdicts, a study of 18,000 people yields much more scientifically valid results.

But more importantly - it also provides us with a great insight into the changing culture and linguistics between today and Darwin's era.

As Wired , which f irst reported on the study, notes: 'Whereas Darwin’s posse perceived the conveyed emotion in one image as "hardness", today’s majority describes it as "bored" - a word that in the 1800s only described what you might have done to a piece of wood.