And now what we've started to do in my lab is to put children into the brain scanner and ask what's going on in their brain as they develop this ability to think about other people's thoughts.
So the first thing is that in children we see this same brain region, the Right TPJ, being used while children are thinking about other people.
But it's not quite like the adult brain.
So whereas in the adults, as I told you, this brain region is almost completely specialized -- it does almost nothing else except for thinking about other people's thoughts
-- in children it's much less so, when they are age five to eight, the age range of the children I just showed you.
And actually if we even look at eight to 11-year-olds, getting into early adolescence , they still don't have quite an adult-like brain region.
And so, what we can see is that over the course of childhood and even into adolescence,
both the cognitive system, our mind's ability to think about other minds, and the brain system that supports it are continuing, slowly, to develop.
But of course, as you're probably aware, even in adulthood, people differ from one another in how good they are at thinking of other minds , how often they do it and how accurately.
And so what we wanted to know was, could differences among adults in how they think about other people's thoughts be explained in terms of differences in this brain region?
So, the first thing that we did is we gave adults a version of the pirate problem that we gave to the kids. And I'm going to give that to you now.
So Grace and her friend are on a tour of a chemical factory, and they take a break for coffee . And Grace's friend asks for some sugar in her coffee.
Grace goes to make the coffee and finds by the coffee a pot containing a white powder, which is sugar.
But the powder is labeled "Deadly Poison," so Grace thinks that the powder is a deadly poison.
And she puts it in her friend's coffee. And her friend drinks the coffee, and is fine.
How many people think it was morally permissible for Grace to put the powder in the coffee?
Okay. Good.
So we ask people, how much should Grace be blamed in this case, which we call a failed attempt to harm?
And we can compare that to another case, where everything in the real world is the same. The powder is still sugar, but what's different is what Grace thinks.
Now she thinks the powder is sugar.
And perhaps unsurprisingly, if Grace thinks the powder is sugar and puts it in her friend's coffee, people say she deserves no blame at all.
Whereas if she thinks the powder was poison, even though it's really sugar, now people say she deserves a lot of blame,
even though what happened in the real world was exactly the same.
And in fact, they say she deserves more blame in this case, the failed attempt to harm, than in another case, which we call an accident.
Where Grace thought the powder was sugar, because it was labeled "sugar" and by the coffee machine, but actually the powder was poison.
So even though when the powder was poison, the friend drank (the powder) the coffee and died,
people say Grace deserves less blame in that case, when she innocently thought it was sugar, than in the other case, where she thought it was poison and no harm occurred.
People, though, disagree a little bit about exactly how much blame Grace should get in the accident case.
Some people think she should deserve more blame, and other people less.
And what I'm going to show you is what happened when we look inside the brains of people while they're making that judgment.
So what I'm showing you, from left to right, is how much activity there was in this brain region, and from top to bottom, how much blame people said that Grace deserved.
And what you can see is, on the left when there was very little activity in this brain region, people paid little attention to her innocent belief and said she deserved a lot of blame for the accident.
Whereas on the right, where there was a lot of activity, people paid a lot more attention to her innocent belief, and said she deserved a lot less blame for causing the accident.