Unlocking Visual Psychology: 6 Design Secrets Every Designer Must Know

Design is closely linked to everyday life, and human psychology can guide us to create products that users love and experience better. Designers need to understand key psychological insights to improve their work.

Overview of "Designers Must Understand Psychology"

The book by renowned design psychology expert Susan Weinschenk presents 100 concise psychological questions that designers must know, each readable in a short moment, revealing the motivations behind design decisions.

Understanding how users observe, think, and decide is crucial for user experience. The book answers questions such as how users browse interfaces, how they think, and what content can guide desired actions.

The content is organized into ten dimensions of psychological knowledge:

How people observe

How people read

How people remember

How people think

How people focus attention

Sources of motivation

People as social animals

How people perceive

Human errors

How people make decisions

Below are the first dimension, "How people observe," with six visual psychology insights for designers.

1. Unique Illusion: Kanizsa Triangle

The left image appears to show a black‑bordered triangle with a white inverted triangle, but actually contains only fragmented lines and three circular gaps. The right image seems to show a white rectangle, yet it also consists of four circular gaps. This illusion, discovered by Gaetano Kanizsa, is known as the "Kanizsa Triangle."

Design tip: Negative‑space logo design

Use this illusion to create distinctive negative‑space logos.

2. Visual Illusion: Müller‑Lyer

The two lines are the same length, but the left line appears longer due to the arrowheads—this is the Müller‑Lyer illusion.

Design tip: Use keylines for visual consistency

When drawing icons, identical sized shapes may be perceived as different; applying keylines helps the brain interpret them as the same visual size.

Human vision consists of central and peripheral vision. Central vision captures fine details; peripheral vision scans the surrounding area.

Peripheral vision is crucial for recognizing overall scenes, often more so than central vision.

Leveraging Peripheral Vision in Page Design

Users use peripheral vision to assess page content; designers should thoughtfully place peripheral elements to enhance experience.

Design tip: Avoid distracting ads

Flashing ads at screen edges disrupt immersive reading; such distractions should be minimized on important pages.

Design tip: Use corners for effective promotions

Well‑designed peripheral ads can outperform central banners, as seen in e‑commerce platforms.

Our brains seek patterns; even random dots are grouped into perceived structures.

Creating Order with Grouping and Spacing

Use regular patterns, spacing, and alignment to give pages rhythm and improve readability.

Design tip: Repetitive visual language

Consistent, patterned graphics can build a strong visual brand across banners and posters.

Design tip: Rhythmic layout for refined pages

Applying uniform spacing and grid systems creates a harmonious visual flow.

Users develop mental models that guide where they look first; altering familiar element positions can confuse them.

1. Primacy of Mental Models

Users tend to scan pages based on expectations, often bypassing top navigation to find desired content.

Design tip: Keep common functions where users expect them

Do not relocate search bars or navigation elements without a strong reason.

2. Reading Order Aligned with Language Habits

Most users read left‑to‑right, top‑to‑bottom, employing immersive reading for understanding and scanning for locating information.

Design tip: Align layout with reading flow

Arrange elements to follow logical task sequences and natural eye movement.

Proximity Principle (Gestalt)

Elements placed close together are perceived as related.

Design tip: Group related items

Place associated elements side by side, use spacing to separate unrelated groups.

Color Vision Considerations

Approximately 9% of men and 0.5% of women are color‑blind, most commonly red‑green. Designers should avoid relying solely on color to convey information.

Design tip: Provide non‑color cues

Use underlines or bold for links.

Combine icons with text for status.

Vary line thickness, texture, or patterns.

Employ distinct patterns to convey meaning.

Choose color palettes that are color‑blind friendly, such as using yellow‑blue contrasts or the viridis palette.

Cultural Color Meanings

Colors carry different meanings across cultures; red may indicate deficit in the West but profit in China, while green can mean money abroad but loss domestically.

Design tip: Research cultural color connotations

When designing for international audiences, consult resources like David McCandless’s colour wheel to avoid misinterpretation.