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Babies learn to aim tools by banging toys

During the first six months of life, a baby’s movements are all over the place, says Bjorn Kahrs. But through the second half year the moves become almost straight up and down, which is what humans do when they hammer at something. (Credit: iStockphoto)

Babies have a natural proclivity for banging, but what may seem like haphazard movements—and a lot of noise—may actually offer hints to how humans learn to use tools.

Tool use develops gradually, beginning in infancy when banging is uncoordinated through early toddlerhood when it is more precise and efficient, new research suggests.


“The movements are all over the place at 6 months old,” says Bjorn Kahrs, a postdoctoral research scientist in the department of psychology at Tulane University.

“But through the second half year the moves become more consistent. It’s almost a straight up and down movement, which is what you do when you hammer at something.”

A study published in Child Development examines the developmental trajectory of banging movements and its implications for tool use development. Researchers studied the movements of 20 babies ranging in age from 6 to 15 months at the Tulane Infant and Toddlers Development Project laboratory.

Reflective babies

Using digital motion-capture technology, they covered the arms and chests of the babies with reflective markers that could be detected by the high-speed motion-tracking cameras.

The babies were handed toy hammers, then allowed to bang to their hearts’ content. As they banged, software transformed the images from the cameras into moving three-dimensional images of the activity.

“The way in which they used their hands went from one that was random to one that was consistent with aiming for a target,” Kahrs says.

The project is part of a more extensive child development study being funded by the National Institutes of Health that is also analyzing how infants develop hand-to-mouth coordination during the first year and how they develop early writing skills.

Source: Tulane University