Viewers of the “climber” event described above—infants and adults alike—readily interpret it in terms of intentional action. First they see the ball as “trying” to move up a hill, but then rolling back down, thereby “failing” to achieve its goal of reaching the top. On some trials, after the ball starts to roll back down, a triangle appears below the ball and seems to “push” it upward, “helping” it get to the top. On other trials, a cube appears in front of the ball and “hinders” it by seeming to “push” it down the hill.

HAMLIN, WYNN, & BLOOM, 2007/RIGHTS MANAGED BY NATURE PUBLISHING GROUP