DesignMove two things together and the eye weds them — whether you meant it or not.
Common fate is the strongest grouping cue in perception: elements moving the same way at the same time read as one unit — outranking colour, shape, even proximity. A murmuration of starlings is thousands of birds seen as a single body, because they turn together. Nothing binds them but shared motion — and the instant they scatter, the body is gone.
Common fate is a Gestalt principle of perception stating that visual elements moving in the same direction and at the same speed are perceived as a single group, regardless of differences in their colour, shape, or position. It is regarded as one of the strongest grouping cues in visual perception.