Science & Technology: I Know What You're Thinking ; Our Ability to Put Ourselves in Another Person's Shoes and `Read Their Mind' is What Makes Us Human. But How Do We Do It?
When James wrote about what Maisie thinks that her step-father thinks she is thinking, he was describing something called the Theory of Mind. This is "the mind's ability to think about the mind," according to Professor Simon Baron-Cohen, from the Department of Experimental Psychology at the University of Cambridge, or, as Dr Helen Gallagher, from the School of Health and Social Care, Glasgow Caledonian University, puts it: "The ability to understand other people's behaviour by recognising that they're different entities with different beliefs, desires and goals from our own."
The Theory of Mind is a fundamental skill, as Dr Gallagher explains. "Thinking about what others think is essential to our capacity to engage in complex social interactions. It underpins our ability to co-operate and empathise but also helps us to deceive and manipulate others."
But what Dr Gallagher realised was that all these studies used myriad cues - facial expressions, body language and memory as well as requiring the subject to think about the task in the past, rather than computing Theory of Mind in the present. What she wanted to do was make people think about another's thoughts without any cues from body language, facial expression or memory. Her volunteers played the game of scissors, paper, stone. Two people have to choose one of the three objects at the same time. Scissors beat paper because they can cut paper, paper beats stone because it can be wrapped round the stone, and stone beats scissors because it can crush them. The volunteers were all men and played a computerised version of the game; half of them believed that they were playing against Dr Gallagher. These men tried to guess what Dr Gallagher would do next, based on the previous choice of object. The part of the brain the men who believed they were playing against a person used was called the paracingulate cortex. "The men were quite cross that I always won," says Dr Gallagher, but, in fact, all the volunteers were playing a computer with a random output.