In order to do his part to help modern science understand what goes on in the minds of children, Jace has gone over to Harvard a couple of times to be an experimental test subject.
Here’s one of the experiments he worked on:
Researchers have determined that 7 & 8 month old babies can recognize the difference between a large object and a small object. They’ve reached this conclusion by showing each baby a small cube a bunch of times until they reach the point that the baby is bored with the object, and will look away fairly quickly if shown the same thing again. If a larger cube is then presented, the baby will tend to stare at it for a longer period of time, thus demonstrating that there is some recognition that the new object is different from the one that the kid had already gotten tired of looking at. This same basic methodology has been used for a wide variety of experiments. For example, it has been shown that babies this age can easily tell the difference between one object and two objects.
One of the grad students at Harvard is interested in the ways babies reason about what she calls “non-cohesive” substances like sand and water versus solid objects. Using something like the experimental approach described above, she noticed that babies did not care about or notice the difference between one pile of sand and two piles of sand, even though the same kids easily demonstrate recognition between one solid object and two. She has a few different hypotheses for why this might be true. For example, one hypothesis is that perhaps infants reason differently about sand than solid objects: “maybe to an infant, one pile or two piles of sand are simply represented as ‘some sand’.”
While Jace was there, she was testing a slightly different hypothesis, which was that, “maybe infants quantify amounts of sand not by number or portions but by total amount and just need a large enough ratio of difference to distinguish different amounts.” So she was comparing babies viewing a large pile of sand versus a small pile of sand. At the same time, she was still also trying to sort out what characteristics of a pile of sand make babies treat it differently from a solid object. So to explore the boundary between these concepts, Jace was actually shown a solid object which was designed to look like a pile of sand. He got to touch it and watch it bounce around on a string in order to understand its solid nature, and then he got to try to distinguish between a big solid fake pile of sand and a small solid fake pile of sand. Unfortunately, I don’t know how he responded, because I had my eyes closed, so as to avoid giving him cues based on knowledge of what was being shown.
So what’s the conclusion? We’ll have to wait until the paper is published before we find out the results…
In the meantime, I have my own hypothesis:
Children view a scene in terms of how they could play with the objects. I can easily imagine Jace thinking to himself, “one teddy bear versus two teddy bears… that’s interesting — I can do all sorts of things with two teddy bears that I couldn’t do with just one. But some sand that happens to be split into two piles instead of one? Who cares? Nothing new to play with there…”
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