A triangle, a circle and a square chase each other on screen — viewers see a love story
In 1944, Fritz Heider and Marianne Simmel showed people a 90-second animation of two triangles and a circle moving around a rectangle, with no faces, sounds or plot. Almost everyone described the shapes as if they were people with intentions, calling one triangle a 'bully' or the circle 'frightened.' The film became a foundational demonstration that humans read agency and emotion into motion automatically, even in bare geometric shapes.