Psychological Bias in UX Design

How human cognitive tendencies shape user behavior—and how we can design for them

Timeline: Pioneers of Cognitive Bias

Source: Compiled from publications by Kahneman, Tversky, Fitts, Hick, and others

Confirmation Bias

People tend to favor information that confirms their existing beliefs, ignoring contradictory data.

Origin: Leon Festinger (1957), Cognitive Dissonance Theory

UX Application: Confirmation Bias

• Design should guide users to re-evaluate assumptions (e.g., onboarding tutorials).
• Use progressive disclosure to shift mental models.
• Example: Netflix recommendation system subtly challenges assumptions by suggesting genre blends.

Hick's Law

The time it takes to make a decision increases with the number of choices.

Origin: William Edmund Hick & Ray Hyman (1952)

UX Application: Hick's Law

• Minimize number of options on screens.
• Use filters, dropdowns, or smart defaults.
• Example: Google homepage with just one input field.

Fitts's Law

The time to acquire a target is a function of the distance to and size of the target.

Origin: Paul Fitts (1954)

UX Application: Fitts's Law

• Make buttons large and close to user’s focus.
• Don’t place important links in hard-to-reach corners.
• Example: Apple's larger target area in iOS toggles and call buttons.

Serial Position Effect

Users remember the first and last items best in a list.

Origin: Hermann Ebbinghaus (1885), later validated by Glanzer & Cunitz (1966)

UX Application: Serial Position

• Place key CTAs at beginning or end of lists.
• Avoid burying critical content in the middle.
• Example: Amazon often puts “Buy Now” and “Add to Cart” at top and bottom of product pages.

Anchoring Bias

People rely heavily on the first piece of information they see.

Origin: Tversky & Kahneman (1974)

UX Application: Anchoring

• Use higher-priced options first to make lower ones more appealing.
• Set expectations with sample outputs or defaults.
• Example: SaaS pricing pages often lead with premium plans.

Cognitive Load

The total amount of mental effort required to complete a task.

Origin: John Sweller (1988), Cognitive Load Theory

UX Application: Cognitive Load

• Break tasks into steps (e.g., progress wizards).
• Use icons and visual cues over dense text.
• Example: TurboTax uses one-question-at-a-time flows.

Loss Aversion

People feel the pain of loss more intensely than the pleasure of gain.

Origin: Tversky & Kahneman (1991)

UX Application: Loss Aversion

• Frame options in terms of avoiding loss.
• Use language like "Don't miss out" or "Limited time left".
• Example: Booking.com uses scarcity and urgency: "Only 1 room left at this price!"

Takeaways

• Psychological biases aren’t flaws—they are predictable patterns.
• Understanding them allows us to design intuitive, persuasive, and ethical interfaces.