Babies are fearless when it comes to heights. That woozy, faint feeling only starts kicking in around month nine, when babies begin to recoil from the edge of a steep staircase or the drop-off of a changing table. Researchers writing in the journal Psychological Science wondered what changed, and they suspected it was the experience of moving around.
The researchers randomly assigned some babies to receive training in using a powered baby go-cart, providing them with locomotor experience, while other babies received no such training. Critically, none of the babies had begun to crawl. The data revealed that infants who used the baby go-cart showed tell-tale increases in heart rate when confronted with the virtual drop-off, indicating that they were fearful; infants in the control condition did not show such increases.
Read the whole story: Smithsonian Magazine