Hick's Law: More Choices, Slower Decisions

Why it exists

Hick's Law was developed to create a mathematical model for a common observation: people take longer to make a decision when faced with more options. It quantifies the relationship between the number of choices and the time it takes to react, moving it from a vague intuition to a predictable principle.

The mental model

Think of it as choosing a TV show to watch. With 5 options on your watchlist, you decide quickly. With 500 options across multiple streaming services, you spend more time scrolling than watching. The time you spend deciding increases with every new option, but the jump from 100 to 101 options is far less painful than the jump from 2 to 3.

How it works

The law states that decision time increases logarithmically, not linearly. This means doubling the number of choices does not double the decision time. The key insight is that as the number of choices grows, the time it takes to make a decision increases at a progressively smaller rate. This is because the cognitive task is essentially a process of elimination, which is efficient with more options.

When to use it

This is a foundational principle in UI/UX design. Use it to justify simplifying interfaces and reducing cognitive load. It applies directly to designing navigation menus, dropdown lists, radio button sets, and any control where a user must select from a list. It's the reason designers break down complex forms into multi-step wizards or use progressive disclosure to hide advanced options until they are requested.

When not to use it

Hick's Law is most accurate for simple, quick-reaction choices where options are roughly equivalent. It's less applicable to complex decisions that require significant reading, comparison, and deliberation, like choosing a health insurance plan. It also doesn't apply if the user already knows what they want and can find it directly, bypassing the scanning and decision process.

One canonical example

A TV remote control. An old remote with 50 buttons is a classic violation; the user has to scan dozens of options to find 'Volume Up'. A modern Apple TV remote with only a few buttons relies on on-screen menus, applying Hick's Law by presenting fewer choices at any given moment. This reduces cognitive load and makes the device feel easier to use.