Dr. Wallace’s Favorite Mental Models

Hick’s Law

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The more options you put in front of someone, the longer they take to decide. That relationship is not a straight line. Each added choice adds a shrinking amount of extra time, so the first few options cost far more than the next few.

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Learn it. Apply it. Save as Skill.

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30-Second Understanding
More choices, slower decisions.

Every option you add places a small, predictable tax on decision time. That tax grows with the logarithm of the number of choices, not with the raw count, so going from 2 options to 4 costs more time than going from 16 to 18.

Core question: How many choices am I really asking this person to evaluate before they can act?

The shrinking cost of each new option

Important: doubling the options does not double the time. The curve bends, so the biggest gains usually come from cutting the first few unnecessary choices, not the last few.

Mental Model Compass

Use it when options are piling up.

The model is most useful when someone has to look at a list, a menu or a set of alternatives before they can act, and speed or completion rate matters.

SimplifyPrimary use case
BeginnerDifficulty
3 minUnderstand
10–30 minApply to a real screen or list
UX and product designMenus and navigationCheckout and formsMeeting agendasCustomer support scriptsDaily decision fatigue
Model at a Glance

Count → Chunk → Cut → Test.

Hick’s Law does not tell you which choice is correct. It tells you how the number and structure of choices affects how long someone takes to choose at all.

01Count

List every option a person must weigh before they can act, including the rarely used ones hiding in a submenu.

02Chunk

Group related options into categories. A large, well-organized set can feel faster than a short, disorganized one.

03Cut

Remove, merge or default the options that rarely change the outcome. Keep the ones that carry real weight.

04Test

Time how long people actually take, and watch where they pause, backtrack or give up.

When Should I Use This?

Recognize the situation.

Open a use case to see what the model changes.

Product and UX
A menu or settings page keeps growing

Group items by task rather than by internal category, and check whether people can jump straight to a known item instead of scanning the whole list. Alphabetical or task-based order lets people search in a pattern closer to halving the list each step, instead of reading it line by line.

Operations
A form has a long dropdown of rarely different values

Chunk the list into a few categories, pre-select the most common value, and move rare options behind a clearly labeled “more options” control rather than deleting them.

Personal
Small daily choices are draining your attention

Pre-commit to routines for recurring, low-stakes choices such as meals or outfits. Removing a repeated decision point frees attention for the choices that actually deserve it.

Customer support
A script tree branches into too many paths

Present four to six top-level reasons first, written the way customers describe their problem rather than how the internal team organizes it, then branch further only once narrowed.

Leadership
Meetings stall on too many live options

Pre-filter proposals to a short list before the room decides, so discussion time goes to real tradeoffs. Keep a visible record of what was cut and why, so filtering does not look like suppression.

Marketing and sales
A checkout or signup page lists many plans and add-ons

Show a small number of tiers with sensible defaults rather than every individual add-on at once. Let people expand to see detail instead of forcing them to evaluate it up front.

Worked Example

A checkout page lists 14 add-ons. Where do you start?

This is an illustrative example designed to teach the method.

14 add-ons, flat list
4 categories, then pick
3 pre-built tiers
1 default, edit optional
SITUATIONStreaming checkout, 14 optional add-ons listed one by one
COUNT14 raw choices stand between the visitor and the “Subscribe” button
CHUNKAdd-ons grouped into four categories: sports, kids, premium video, ad-free
CUTA sensible default plan is pre-selected; add-ons collapse behind “Customize”
INSIGHTDecision time drops sharply without deleting a single real option
NEXTWatch for the opposite failure: hiding the one add-on most visitors actually want
Do not conclude: “Fewer visible options means a better decision.” Hick’s Law predicts decision speed, not decision quality. A fast choice can still be the wrong one.
History and Accuracy

The law has a longer history than one 1952 paper.

Expand for the research behind the logarithmic relationship and where it holds less well.

What did Hick actually study?

William Edmund Hick published “On the rate of gain of information” in 1952 after experiments using ten lamps arranged in a circle, each paired with a response key. He was building on earlier observations: Franciscus Donders had reported in 1868 that reaction time rises with the number of possible responses, and Jakob Merkel found in 1885 that response time increased as the stimulus set grew larger.

What did Ray Hyman add?

Ray Hyman’s 1953 follow-up experiments, using arrangements of lights, established a close-to-linear relationship between reaction time and the information carried by the number of choices. Because of this, the formal version is often called the Hick-Hyman law.

What is the actual formula?

For equally likely choices, T = a + b × log2(n + 1), where T is reaction time, n is the number of choices, and a and b are constants fitted from the data. The “plus 1” accounts for the uncertainty of whether to respond at all. The key point for everyday use: doubling the number of choices does not double the time it takes to choose.

Where does the relationship break down?

A 2018 review by Proctor and Schneider documents real exceptions: well-learned verbal responses to familiar stimuli barely slow down as choices increase, eye movements between targets often show no increase or even a decrease, and searching an unordered list tends to follow a straight line rather than a logarithmic curve. Treat the law as a strong default for unfamiliar, deliberate choices, not a universal constant.

Common Mistakes

Simple does not mean foolproof.

Treating speed as quality

Hick’s Law predicts how long a decision takes, not whether it was the right one. A faster choice is not automatically a better choice.

Assuming a straight line

Doubling the options does not double the time. Because the curve bends, the first few unnecessary choices usually cost more time than the last few you could trim.

Ignoring chunking

Twelve flat, unsorted options can feel slower than twelve well-grouped ones. Good categories effectively shrink the number of things a person weighs at once.

Cutting to look simple

Hiding an option people actually need just pushes the search somewhere else, often adding frustration, a support ticket, or an abandoned task.

Applying it to trained experts

A well-practiced, automatic response, such as an experienced pilot’s trained reaction or a familiar keyboard shortcut, does not slow down the same way a novel decision does.

Using it to rush group decisions

Trimming a team’s options to speed up a meeting can quietly suppress real disagreement. Check this against Groupthink and the Abilene Paradox before calling a quick decision a good one.

When Not to Use It

Some decisions should stay slow.

Use full disclosure when...

legal, medical or financial rules require presenting every material option, even if that makes the choice slower.

Use expert defaults when...

the person is a trained specialist whose speed already comes from practice, not from a shorter menu.

Use deliberate friction when...

the decision is high-stakes or hard to reverse, and you want people to slow down and consider more, not less.

Counterpoint: fewer options can also mean less real choice. Ask who decided which options survived the cut, and whether what remains still covers people’s actual range of needs.
Combine It With

One model rarely does the whole job.

Try It Yourself

Build a choice-simplification prompt.

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Your AI-ready prompt

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Save as Skill

Turn this mental model into a reusable AI skill.

Save as Skill converts the model into portable Markdown instructions that teach an AI when and how to apply Hick’s Law, what questions to ask, what evidence to seek, what mistakes to avoid and how to structure its analysis.

Build your own Mental Models Skills Library

Save the skills you find useful and organize them into your own reusable library. The Markdown is intentionally model-neutral, so it can be used wherever an AI system accepts uploaded files, project knowledge, custom instructions or reusable text context. Platform capabilities differ, so this is a portable skill file rather than a claim of one-click installation.

Go Deeper

For readers who want the nuance.

Does Hick’s Law mean I should always offer fewer options?

No. It predicts time, not whether a shorter list is better. Good chunking and layout can let a large set feel fast, so the goal is matching structure to the real decision, not minimizing the number shown on screen.

How does chunking actually help?

People appear to subdivide a large set into smaller groups and eliminate roughly half of the remaining options at each step, a strategy that resembles a binary search. This is one reason a long, well-organized list can outperform a short, disorganized one.

What is stimulus-response compatibility, and why does it matter here?

When the layout of options matches how people naturally expect to respond to them, reaction time drops regardless of how many options exist. A menu arranged the way people already think about the choice can beat a shorter menu arranged in a confusing order.