Babies perform pure reasoning

Gibberish may come out of the mouths of babies, but their minds are able to form surprisingly sophisticated expectations about how events should unfold.

Researchers at Massachusetts Institute of Technology (MIT) have developed a computational model of preverbal infants' pure reasoning abilities that accurately predicts their surprise at situations that deviate from basic rules of the physical world.

They studied 60 one-year-old Americans who participated in a series of experiments that gauged how long they would look at animated scenarios that were routine. In one case, the babies were shown four objects - three blue, one red - bouncing around a container. After some time elapsed, the scene would be covered and one of the objects would be removed from the container through an opening. Based on prior research showing that infants look longer at unexpected events, the study showed they would be surprised if the object farthest from the opening disappeared when the scene was blocked very briefly, for 0.4 seconds. With a two-second interval, they showed surprise only if the red object disappeared first.

The computational model correctly predicted how long babies would look at the same exit event under a dozen different scenarios and varying number of objects, positions and time delays. This suggests that infants reason by mentally simulating possible scenarios and figuring out which outcome is most likely based on a few physical principles.

The research is part of a larger effort to observe babies at 3 months, 6 months and 12 months, and map out their perceptions of the physical world. The researchers are in the midst of developing similar computational models of infants' intuitive psychology, or their understanding of how people act. These models could help scientists understand about changes in the human brain when a child develops autism, which often involves an inability to form appropriate expectations of social behaviour.