Generally, humans recognize that while animate objects can create order, inanimate objects can only increase disorder (although I’m sure you Arsians will come up with several clever counterexamples). For example, avalanches and bouncing balls can’t assemble do-it-yourself bookshelves, but they sure can knock them down. A new study in PNAS last week showed that children as young as one year old can understand of the difference between the type of agents that can increase order and those that cannot.

In these experiments, children were shown an image or video featuring either an animate object or an inanimate object. This object was shown approaching a set of blocks, which was either ordered neatly or in disarray. However, when the object intersected with the blocks, the video was blacked out. Then, the children were shown the aftermath of the convergence: either an ordered set of blocks or a chaotic set.

These pictures and videos were arranged in several scenarios: some children saw an animate object (such as a hand) approaching an ordered set of blocks, then were shown a disordered set of blocks, implying that the hand sent the blocks into disarray. Another group of children were shown a messy set of blocks that “became” ordered via the hand. Two other groups of subjects were shown these same two sequences, yet with an inanimate object (such as a rolling ball), performing the action.

Depending on the amount of time the children looked at the resulting set of blocks, the researchers inferred how surprised they were by the series of events: the longer they looked, the more unexpected they found the outcome. The events in which inanimate objects seemed to create order were expected to be the most surprising to the children.

There was no difference in the responses of 7-month old children to ordering and disordering events for either the animate or inanimate objects; it seems that they had no expectations about what the objects can and can't do. However, 12-month old children looked significantly longer when the rolling ball created order than when it caused chaos.

They were not surprised, however, that the hand could either create order or increase disorder. These results suggest that a child’s expectations about animate and inanimate objects may develop between 7 and 12 months.

Interestingly, it’s very hard for children to actually verbalize these expectations. In another part of the study, children aged 3 to 6 were told a story about a boy who went outside to play. Half the children were told that his sister came into his room and changed things, while the other half were told that the wind blew into the window and changed things. The children were then showed two pictures—one of a clean room and one of a messy room—and asked which picture the room looked like when the boy came home.

While most of the children picked the correct picture (the sister could cause either the clean or messy room, but the wind could cause only the messy room), very few could explain why they chose the picture they did. For example, one girl who picked the clean room in response to the sister story explained that “She made it like that because it was beautiful.” Although children as young as one year old seem to understand this difference between animate agents and inanimate objects, children as old as six still can’t verbalize these expectations.

At the end of the paper, the authors suggest that this early ability to see animate agents as responsible for order—and inanimate objects capable only of disorder—may help explain some people's tendency toward creationism. Those who extend this framework too far and mistakenly assume that all observable patterns are a result of intentional work by an animate agent may be especially unwilling to embrace evolution.

PNAS, 2010. DOI: 10.1073/pnas.0914056107 (About DOIs).