Researchers developed a video to figure this out. In it, characters (who look like tiny blobs) attempt to reach various goals by jumping onto higher blocks, or jumping from one tall block to another one with a gap between. Some characters take risky maneuvers, while others go through a safer route. When 10-month-olds (80 of them, to be precise) watched these characters, they paid more attention if a blob took a high-risk route to an object it had previously taken a low-risk route for. The longer look suggests infants were surprised by what they saw.