Law of Proximity
Place related things close together and separate unrelated things with more space.
Distance can explain a group before any label does.
Picture a form with four questions. Each label sits close to its field, and a wider gap separates each question from the next. The structure is clear before you read. Remove those spacing differences and the form becomes one block.
Origin
Max Wertheimer described proximity as a grouping principle in 1923. In his dot patterns, elements separated by the smallest gaps were usually seen together. Modern reviews still treat proximity as a basic cue in perceptual grouping.
Keep labels, values, and controls close to the content they describe. People should not have to trace across the page to work out what belongs together.
Use a smaller gap inside a group and a larger gap between groups. The difference matters more than choosing one universal spacing value.
Check the grouping at every screen size. A responsive layout can accidentally separate a label from its control or pull unrelated items together.
Do not expect color or borders to repair misleading spacing. Start with a clear spatial relationship, then add other cues when they help.
Digital systems
Form Labels and Fields
A label placed close to its input reads as part of that field. A wider gap before the next label separates one question from the next without adding boxes or divider lines.
Physical signals
Tables in a Cafe
People sitting around one table are usually read as a group. The larger gap to the next table separates two groups even when the chairs and tables look the same.
When every gap is the same, the page loses its structure. People have to read each item before they can tell which label, control, or message belongs to which group.
Keep related items close and open more space between separate groups. Use the same spacing pattern throughout the interface so the relationship stays predictable.