What Is Hick's Law?
In 2000, researchers Sheena Iyengar and Mark Lepper set up a tasting table in a California grocery store. On one day shoppers saw 24 flavours of jam; on another, just 6. The 24-jam table drew more browsers, but only 3% of them bought a jar. At the 6-jam table, 30% did - ten times the conversion, from a quarter of the options.
That result is a real-world demonstration of Hick's Law (formally the Hick-Hyman Law): the time it takes to make a decision grows with the number and complexity of the choices on offer. William Hick documented the relationship in 1952 in "On the Rate of Gain of Information"; Ray Hyman extended it in 1953 with "Stimulus Information as a Determinant of Reaction Time." The formula - T = a + b × log₂(n + 1), where T is decision time and n is the number of choices - comes from information theory, not guesswork.
"The time it takes to make a decision increases with the number and complexity of choices." - Laws of UX
Why Designers Must Care
- Navigation menus with a dozen top-level items force scanning, comparing, and second-guessing before a user commits to a click.
- Product pages with several competing calls to action produce hesitation - and hesitation on the web usually ends in leaving, not deciding.
- Onboarding flows that expose every setting on day one slow first-time users down before they've seen any value.
How to Apply Hick's Law
- Cap primary navigation. Five to seven top-level items is a reliable range; push depth into progressive disclosure rather than a flat, wide menu.
- One primary action per screen. If there's only one thing a user should do next, make it visually dominant and unambiguous.
- Group before you list. Twenty items sorted into four labelled categories of five let users skip whole branches by reading one label.
- Mark a recommended option. "Most popular" pre-decides for hesitant users without removing choice for anyone else.
- Stagger complexity. Introduce advanced features after the basics are working, not in the same screen.
Real-World Examples
Apple's original Siri Remote for Apple TV (2015) shipped with about half a dozen buttons and a trackpad, in place of the dense button grid found on a typical universal remote. Fewer controls meant less scanning and fewer wrong presses. Google's homepage takes the idea further: one input field on an otherwise empty page removes every competing decision before the user has typed a character.
Key Takeaways
- More choices mean slower decisions and a higher risk of no decision at all - Iyengar and Lepper's jam study put a number on it: 3% versus 30%.
- Grouping and categorisation reduce apparent choice without cutting capability.
- A recommended default speeds up hesitant users without constraining anyone else.
- Apply Hick's Law hardest where abandonment is most expensive: checkout, sign-up, and primary navigation.
