Optimization glossary

Decision fatigue

What is decision fatigue?

Decision fatigue is when the mind becomes fatigued after a sustained period of decision making. Making decisions is a cognitively taxing process, and decision making ability declines after long sequences of decisions.

Why is it important to think about decision fatigue?

It is important to consider the effects of decision fatigue when designing your website or mobile app, because users only have a limited amount of cognitive bandwidth, and presenting them with too many decisions and options can cause them to become overwhelmed.

Presenting users with too many choices at once can lead them to take the cognitively easy route and not make any decisions at all, leaving your site entirely.

It is always a good practice to limit the number of actions a user can take at any given point in the user flow and make the navigation process as frictionless as possible. This reduces the amount of willpower a user needs to complete your desired user flow. The temptation for website owners is often to throw everything that a user could possibly want onto their homepage, but a strong web design requires restraint and thoughtful selection of the big decisions versus all of them at once.

What causes decision fatigue?

Decision fatigue is caused by being forced to make too many decisions over a fixed period of time.

When users begin a decision-making process, they start by weighing their choices carefully. Over a period of time, their mental energies become sapped from the effort spent weighing all the various trade-offs and requiring people to use willpower instead of default systems.

Once their mental energy is depleted, users are reluctant to engage in the thinking that requires them to make these trade-offs due to the cognitive effort their brain must exert. People mindful of this will often structure their to-do lists to include important decisions that require the most mental energy to be early in the day, to ensure they have mental energy to give to these items first.

Users with decision fatigue become ‘cognitive misers,’ hoarding their energy as their self-control is used up and effectively shutting down their capacities. They end up taking the path of least resistance, which is sometimes a complete shutdown, resulting in no or poor choices.

Decision fatigue is linked to the ‘paradox of choice,’ made famous by the Columbia University’s research project on jam samples which showed that more choices don’t lead to a higher conversion rate. In fact, people overwhelmed by too many choices can end up making no choice at all.

When 6 flavors of jam were available, 30% of those who tasted samples made a purchase. When 24 flavors of jam samples were made available to shoppers, only 3% who tasted the jam samples went on to make a purchase. Even small decisions become overwhelming with the introduction of the 'paradox of choice'.

Another example, is that of Roy Baumeister and his colleagues who saw that making test participants resist the temptation of eating chocolate chip cookies they could both see and smell by instead eating radishes made them have less energy to persist when trying to solve a puzzle that both the cookie eating group and the radish eating group were subsequently given. This single experiment showed that willpower was a scarce resource that could be depleted over time, causing the participants to not have the energy to make good decisions, like pressing on to solve the puzzle.

Decision fatigue often also increases as the end of the day due to the amount of daily decisions that have already been made, so it's important to consider what time of day users come to your site the most.

How to avoid decision fatigue

The best way to avoid decision fatigue in your users is to minimize the number of decisions they need to make or to space them out strategically throughout their path.

When designing your website or app, make sure to design your customer path with as few choices as possible and that important decisions are early on – moving the customer down the path towards one conversion goal and one call to action.

In addition to reducing the choices available, marketers can also make default choices for their consumers, for example selecting more expensive add-ons and making them look like a good decision, subtly nudging them towards spending more.

Additionally, making customer journey paths that feel familiar with other daily routines a customer might already have can be helpful to reduce the amount of additional decision making that can lead to poor decisions around conversion.

By doing the decision making for your users, you free up their mental energy and attention to complete their desired objectives of your site, leading to higher conversions.