What psychological principle refers to the tendency to fill in gaps in incomplete figures?

The principle that refers to the tendency to fill in gaps in incomplete figures is known as closure. This Gestalt principle suggests that our minds are inclined to perceive a complete image even when part of the visual information is missing. For example, when presented with a circle that has breaks in its outline, our perception tends to "close" the gaps, and we see a complete circle rather than an incomplete shape. This cognitive process demonstrates how our brains actively interpret visual information to create a coherent structure, relying on learned patterns and context.

In terms of the other concepts: proximity relates to how we group items that are close together, similarity refers to our tendency to group figures that share similar characteristics, and continuity describes our perception of lines or patterns that are smooth and uninterrupted. While these principles contribute to how we perceive and organize visual information, closure specifically highlights our ability to complete incomplete forms, making it the correct answer for this question.