I imagine many readers of this blog will have already seen Paul Bloom’s NYT magazine article on “the moral life of babies”:http://www.nytimes.com/2010/05/09/magazine/09babies-t.html?ref=homepage&src=me&pagewanted=all. There’s a lot of interesting stuff in there, but I wanted to focus on something about false beliefs that surprised me. Here’s what Bloom says.

bq. The new studies found that babies have an actual understanding of mental life: they have some grasp of how people think and why they act as they do. The studies showed that, though babies expect inanimate objects to move as the result of push-pull interactions, they expect people to move rationally in accordance with their beliefs and desires: babies show surprise when someone takes a roundabout path to something he wants. They expect someone who reaches for an object to reach for the same object later, even if its location has changed. And well before their 2nd birthdays, babies are sharp enough to know that other people can have false beliefs. The psychologists Kristine Onishi and Renée Baillargeon have found that 15-month-olds expect that if a person sees an object in one box, and then the object is moved to another box when the person isn’t looking, the person will later reach into the box where he first saw the object, not the box where it actually is. That is, toddlers have a mental model not merely of the world but of the world as understood by someone else.

I think the Onishi and Baillaregon paper he is referring to is “Do 15-Month-Old Infants Understand False Beliefs?”:http://www.sciencemag.org/cgi/content/short/308/5719/255, which isn’t behind a paywall. It’s a very interesting study. It certainly seems like a decent challenge to the (Rutgers-inspired) view that children don’t understand that beliefs can be false until they are nearly 4.

I’m not an expert on any of this stuff, so I’m probably missing a lot, but here’s a crude summary of what the experiments seem to show. The more difficult you make the task you set an infant in a false belief task, the later they make the correct ‘predictions’. That’s not too surprising, but what is surprising is how much difference this can make. If you just see what a baby expects by tracking where it looks, then 15-month olds have expectations that allow for the falsity of beliefs. If you try to get the child to explain the action of an agent with false beliefs, or complete some other kind of demanding verbal task, they don’t allow for false beliefs until they are well into their 4th year.

This seems to suggest, to me at least, a kind of System 1/System 2 story. The automatic system that controls things like eye movements, surprise reactions and the like, allows for false beliefs from a very early age. But when babies get the capacity to reflectively reason (which I assume is much later than 15 months) their reflective thought seems not to allow for false beliefs. They don’t incorporate false beliefs into their explicit reasoning for years and years after their automatic processes are sensitive to them.

As I said, this is all a guess based on non-expert reading of a few studies. The main thing I wanted to highlight here is that people should be reading the new studies, especially people (like me) who didn’t realised that the experimental data on infant’s theory of mind look a lot more complicated now than they did in the 1980s.