There’s a famous experiment where you show a three year old kid a smarties tube and ask what they think is inside. They’ll probably say ‘smarties’. (Smarties =BrE chocolate sweets, rather like M&Ms) Then you open it, and show them there are pencils inside. Next you close it up again and ask, ‘If Mummy saw this tube, what would she think is inside?’ The three year old will probably say ‘pencils’. It won’t occur to them that Mummy might be fooled by the packaging in the same way that they were.
Try the same thing with a five year old and ask the same question, and most likely they’ll say there are smarties inside. So somewhere between the ages of 3 and 5 kids seem to work out that other people can have a different set of beliefs and understanding from their own, and they develop the ability to think about another’s thoughts.
I’m intrigued by how this theory of mind develops – or doesn’t develop. It has often been studied in relation to people on the autistic spectrum who may interpret remarks very literally. So for example, if someone asks ‘Is that your jacket on the floor?’ they might just think it’s an enquiry about whether the jacket belongs to them and fail to recognize a request to pick it up. Before we can begin to understand another speaker’s intentions, we have to understand that they can have beliefs and desires that are different from our own.
Scientists have identified the bit of the brain we use to think about the thoughts of others. I’ve just watched a video where I’ve learnt that this bit of our brains is also involved in making ethical judgments. It’s a talk by a neuroscientist, Rebecca Saxe, in which she describes how applying a magnetic pulse to the right temporal parietal junction can change our normal moral judgments – largely for the worse it seems. Here’s hoping Rebecca continues to refuse calls from the Pentagon.