What is the Hick-Hyman Law?

Hick’s Law Video

Hey, guys! Welcome to this Mometrix video on the Hick-Hyman law, more commonly known as Hick’s law.

Calculating Reaction Time

This law is named after the American psychologist Ray Hyman and the British psychologist William Hick.

Hick’s law states that the time it takes for a person to make a decision increases as the amount of possible choices increase. So, essentially, Hick’s law illustrates one’s ability to make decisions with different amounts of uncertainty.

To fully understand this, there are a few terms you need to be familiar with:

  • Reaction time – reaction time refers to the time between the onset of a stimulus and the start of the response.
  • Movement time – movement time is the time it takes to complete the onset of a movement.
  • Response time – response time is the time it takes to process information and then to make a response.

reaction time + movement time = response time


Now, there are different types of reaction times.

There is the simple reaction, which is relevant to a single stimulus and a single possible response.

Then there is choice reaction time, which means that there are several stimuli given, but only one must be selected for response; and as Hick’s law states, the more choices a person has, the slower their reaction time.

There are several factors that affect reaction time:

  • Age – someone’s age can play a role into how fast or how slow they react. As a person gets older, their reaction time becomes slower.
  • Gender – on average, males have faster reaction times than females do; however, reaction times reduce less with age in females than they do with males.
  • Stimulus intensity – increasing the stimulus intensity will also improve one’s reaction time. For example, a loud bang will increase our reaction time more so than a more quiet bang.
  • Height – taller people will have slower reactions, because of the greater distance the information has to travel from a person’s brain to the active muscles. Shorter sprinters tend to win shorter races.
  • Level of Alertness – being more alert can improve reaction time.


Hick actually came up with an equation to calculate reaction time:

reaction time = movement time + processing speed × log²(n)<\p>


In this case, n is the variable for the number of choices.

You can find application for Hick’s law wherever you look. Advertising companies use it to determine features on their websites, restaurants use it to determine certain features on their menus, it’s used to output effective commercials, and so on.

I hope this video was helpful. See you next time!



by Mometrix Test Preparation | Last Updated: February 12, 2024