Introduction
The Gestalt school of psychology was founded in early twentieth-century Germany. The essence of Gestaltism is that “the whole is greater than the sum of its parts.” While the visual world is physically composed of small, individual elements (colors, lines, blobs, etc.), the Gestaltists showed that we naturally and automatically perceive the world as perceptual groups—combinations of elements that are different than the elements in isolation. The Gestaltists went on to describe a number of “principles” that appear to guide the organization of elements into perceptual groups. These principles are demonstrated in this activity.
The initial image the user sees is a 5 × 5 array of homogeneous elements (green circles). As the user views each grouping principle, see some of the elements change. These changes will cause the user to perceive some or all of the elements as belonging to distinct groups.
Similarity
Elements that are similar to each other group together.
In the first example, the second and fourth columns of the grid of circles becomes blue. The image now seems to be organized into columns, whereas the organization was ambiguous before. Items with similar colors automatically seem to group together.
In the second example, the second and fourth rows become stars, while the first, third, and fifth rows are composed of circles. The image now appears to be organized in rows. Items with similar shapes automatically seem to group together.
Proximity
Elements that are relatively close to each other group together.
Initially, the green circles are organized in a 5 x 5 grid with the elements equally spaced apart. It does not appear to be organized into either rows or columns. In the first example, the green circles are moved closer together vertically, causing the display to group into columns. In the second example, the circles are moved so that they are close to each other horizontally, and the display seems to break into rows.
Good Continuation
Elements group to form smoothly continuing lines.
In this example, the dots are moved close together and form two intersecting lines that cross in an X shape. The natural tendency should be to group the elements into two lines, with one line going from upper left to lower right, and another going from upper right to lower left.
Note, however, that this is not the only possible interpretation. One could imagine the dots to be organized as a V on top and an inverted V on the bottom, with the points of the two Vs meeting in the middle. However, this is not the typical impression one has when viewing the display. The principle of good continuation causes the dots to appear grouped together like two diagonal lines crossing to form an X.
Common Region
Elements perceived to be part of the same region group together.
In this display, the grid of green dots is displayed with the dots being close together in the vertical dimension, which should cause the display to be perceived as forming columns according to the grouping principle of proximity. However, there are three orange rectangles beneath the first, third, and fifth rows of dots, causing them to be perceived as grouped horizontally rather than vertically. The green circles group into rows because some of them lie within the same rectangular orange region. Without these orange regions, the dots would group into columns rather than rows. This indicates that common region is a stronger Gestalt grouping cue than proximity.
Connectedness
Elements that are connected to each other group together.
At first, the display starts with the standard 5 x 5 grid of green dots, which does not appear to group vertically or horizontally. Next, the green dots are each connected by vertical lines to the dots above and/or below them, making them appear to group into columns. This is a powerful grouping principle. Finally, an entirely different configuration of green dots is connected by black lines, and all the dots that are connected by lines immediately seem to be part of the same perceptual group.
Parallelism
Parallel elements group together.
In the display, five twisted but mostly vertical lines are shown. Two of the twisty, vertical lines are parallel with each other, and they seem to group together more than they do with the other lines in the display.
Symmetry
Elements that are symmetrical to each other group together.
In the display, twisted but mostly horizontal lines are shown. Two of the twisty, horizontal lines are mirror images of each other, and they seem to group together more than they do with the other lines in the display.
Common Fate
Elements that move in the same direction group together.
The first display is the standard 5 x 5 grid of green dots. In the next display, nine of the dots start moving diagonally, in lock step with each other. These nine dots instantly appear to group together because of their common movement.
Synchrony
Elements that change at the same time group together.
The display contains a 5 x 5 grid of many different colored dots. None of the dots seem to group together at first. After clicking the display, some of the dots change color at the same time and immediately seem to be grouped. The synchronous change of color causes the perceptual system to treat them as a single unit.
Conclusion
In some of the images in this activity, you may have noticed that two or more principles are actually in effect. Sometimes the principles contradict each other, with each one pulling you toward a different interpretation of the image. At other times, the principles are complementary, converging to push you toward a single interpretation.