Who Pays the Bill for Thinking?

COCenk Onur Ozan ·6 Aug 2026Published 6 Aug 2026 ·4 min read

The human brain makes up only about two per cent of our body weight, yet even at rest it uses roughly a fifth of the body’s energy. Every thought, every choice and every decision carries a quiet cost. Seen from customer experience, employee experience and VoC, that is a very important fact, and one that is often overlooked. I believe protecting customers and employees from unnecessary thinking should sit at the centre of experience design.

The brain’s energy economy is well known in neuroscience. The study Marcus Raichle and his colleagues published in 2001 is among the key works showing that the brain stays highly active even when it seems idle, and how much energy that takes. The brain is constantly busy processing information, making decisions and responding to what is around it. Conscious, complex decisions add to mental fatigue, and a tired mind either postpones the decision, avoids complicated processes or falls back on automatic choices. That is why, when you design a brand or a service, you need to account for the customer’s mental energy cost.

The ideas Roy Baumeister and his team developed from 1998 onwards suggested that mental fatigue lowers the quality of decisions; the concept we now call “decision fatigue” comes from there. Some of those findings later proved hard to replicate, but everyday observation points in the same direction: tired people put decisions off or reach for the easier option that brings short-term relief. A shelf lined with fifty kinds of coffee beans can feel exciting at first. The longer the choice drags on, the harder it gets, and in the end you either walk away with nothing or pick a bag at random. Amazon’s one-click purchase and the saved favourite orders in the Starbucks app exist precisely to reduce this fatigue.

The same energy question applies to employees. Sapolsky’s work on primates shows that individuals on the lower rungs of a social hierarchy live with chronically high levels of stress hormones. In organisations you can see a similar load in employees who have little say, are constantly monitored and deal with complicated processes. Think of a call-centre agent trying to keep up with several customers at once while holding long procedures in their head. They produce a separate decision for every customer, and each one costs energy. Chronic stress and a heavy mental load increase errors and lower satisfaction, and this shows up directly in the customer experience.

Brands compete on an invisible field: how well they manage the mental energy of customers and employees. Every extra option and every complicated step sends a bill to that energy. A confusing category structure, weak filters and a long checkout wear customers out on an e-commerce site and push them to abandon their basket. If a bank’s internal procedures are complex, employees have to make a separate decision for every transaction, which tires them and reaches the customer too. Good design lowers this cost, and it is not limited to the interface; processes, communication and company culture can do the same job.

In Sapolsky’s work, empathy and social context are among the factors that determine behaviour. Under pressure, it becomes harder for employees to show empathy to customers, and stressed customers give more negative feedback. Psychological safety and support mechanisms protect employees’ mental energy and increase their capacity for empathy. It is no surprise that a customer service team that gets support during the busy season feels less stress and has better conversations with customers; you can see the trace of this in VoC measurements, in customer satisfaction as well as employee engagement.

The lesson I draw is this: thinking is expensive, and simple design is valuable. Simplifying menus, limiting options to the ones people really need and shortening checkout and sign-up are the first steps. Giving employees autonomy and cutting complicated procedures is the same principle seen from the inside. Empathy belongs at the centre, because a tired mind first wants to feel good. This approach also matches the two systems Kahneman describes in Thinking, Fast and Slow. Fast thinking is economical in energy terms; slow thinking is mentally costly. In experience design, the aim is not to force people into slow thinking unless it is truly needed.

The support team I described in Thinking About Sapolsky in a Bank Branch is a good example: new scenarios every day, long procedures and managers who kept stepping in wore out employees and customers alike. Once the company simplified its processes and gave employees decision-making authority and psychological support, the mental load eased, and both customer satisfaction and employee motivation went up.

The human brain is an expensive machine to run, and loading that cost onto customers or employees directly lowers the quality of the experience. Making processes predictable, lightening employees’ mental load and looking at observed behaviour as well as survey answers in VoC are ways to reduce it. Thinking comes with a bill. In your company, who is paying it?

Cenk Onur Ozan COO, Cloud4Feed

Writes about customer experience, behaviour and the decisions that follow from listening.

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