Common Fate - Common fate is a Gestalt concept the refers to the visual tendency to group shapes together if the shapes move in a similar direction. The shapes do not have to exhibit similarity or exhibit proximity.
Before playing the animation, examine how groups are perceived.
The circles create one group due to similarity and the squares to the right create a second group due to similarity. All of the figures can be perceived as one large group due to proximity.
Now play the animation and examine how common fate alters the previous sense of grouping.
Look at the image above and determine what would be a group, then watch the animation below.
Pausing the animation at almost any point makes it difficult to distinguish groups. However, when motion is visible and common fate is exhibited, a group of orange circles becomes apparent.
Common fate allows the perception of figures that would be imperceptible without motion.