In the late 1890s, a horse named Clever Hans was deemed the smartest in the land and some people thought the horse could read minds… Hans was said to have been taught to add, subtract, multiply, divide, work with fractions, tell time, keep track of the calendar, differentiate musical tones, and read, spell, and understand German. If you asked Hans how many people in the audience were wearing glasses, he would count out the answer by tapping his hoof. In September, 1904, The New York Times published an article about Clever Hans (here).
Sorry for the buzz kill, but Clever Hans was not special, different or capable of reading minds. Clever Hans was able to read non-verbal communication from humans, just as any other animal can. On the most basic level, single verbal commands, a pointing finger or fear on a face all communicate state of mind to a domesticated animal. Ask any dog owner about how sensitive the pet is to them when they are mad, happy or sad and you will hear more stories than you want. Innately, animals have had to learn from nonverbal communication in order participate socially and even survive in their environments. For centuries, facial expressions, vocal tone and pitch and body language have provided crucial clues to animals about the intent and needs of humans. Clever Hans used these clues from his audience and trainer to define his behavior.
So if Hans could not perform math problems and other such tasks, how was he able to accurately answer questions from his handler? The answer is found in a behavior modification program created by his owner. Clever Hans was rewarded for sustaining the behavior of hoof tapping, until he was told to stop. Here’s what is interesting — Hans was told to stop only through non-verbal behaviors of the audience or the owner himself. Hans monitored changes in the questioner, or audience member’s, facial expression, pupil dilation, head position, respiration rate and even body language top determine when to stop his behavior of tapping.
Clever Hans learned that when a question was asked, he would start tapping his hoof. Hans would only stop when someone, that knew the answer, inadvertently showed emotion, possibly excitement, that the correct amount of tapping had taken place and therefore Hans could stop. The behavior was then validated because Hans would receive a treat for being correct. It was not until years later did scientists understand exactly how Clever Hans was able to accomplish such seemingly complex tasks. Ultimately, a blind folded Clever Hans could not answer any questions correctly.
Over a hundred years later, pupil dilation is still an important nonverbal metric that provides insight. The pupil response to cognitive and emotional events occurs at an incredibly small scale, with changes generally less than half a millimeter. By recording subjects’ eyes with infrared cameras and controlling factors that might affect pupil size, such as ambient brightness, color and distance, technical experts can use pupil movements as a proxy for other processes, like mental strain or emotional interest.
In the end, no one can read minds. But when you are searching for innovation or even just better solutions, content and products; consider quantifying the surrogate markers for what is happening in the deepest levels of the mind. These surrogate markers may highlight underlying beliefs and predict future behaviors.