What is Mental Load?
For most of us, the first thing we do in the morning is open our phone and scroll through social media. Within seconds, information from across the globe floods our minds, trying to trigger an emotional response—and often succeeding. Most of it has no real impact on our lives, and by the time we go to bed, we’ve already forgotten it. But in that brief moment, we have to process what we see, using up a limited resource: our mental space.
It might not feel like a big deal—how much harm can a short video or tweet really do? But because each piece of content delivers a quick dopamine hit,[1] we begin to crave more… and more… and more. By the time we finally get out of bed, we’ve already used up a chunk of our mental space—space we’ll be missing in other parts of our lives throughout the day.
As the day goes on, every advertisement, email, news headline, and notification demands another sliver of our attention. Each one nibbles away at what’s left of our mental capacity.[2]
And that can have real consequences.[3] As our mental space shrinks, so does our ability to make good decisions. With less cognitive energy available, our brains begin to rely more heavily on mental shortcuts—also known as cognitive biases—when navigating daily choices.
Daniel Kahneman, in his book Thinking, Fast and Slow, describes the brain as operating through two systems: System 1 and System 2.[4] System 1 is our default mode—fast, automatic, and effortless. It leans on mental shortcuts to conserve energy. System 2, on the other hand, is slow, deliberate, and requires real effort. When we’ve depleted our mental space, we simply don’t have the capacity to engage System 2 as often. So, we fall back on System 1, making us more vulnerable to the cognitive biases baked into that system.
Here’s a simple example: It’s the evening after a busy workday. Your brain is tired from processing information all day long. Now it’s time to decide what to eat for dinner. If your mind were fresh and your mental space intact, you might engage System 2 and consider several options—factoring in health, budget, and how much effort a meal would take. But if you’re mentally exhausted, you’ll default to System 1. Your decision will likely be influenced by cognitive biases [5] like the availability heuristic, which leads you to pick the first thing that comes to mind—often something easy, comforting, unhealthy, and maybe expensive.
Many people like to think their food choices—or any daily decisions, really—are just a matter of willpower. But in reality, those choices are often shaped by mental load. One of the most effective ways to improve decision-making isn’t to beat yourself up for bad choices [6] —it’s to reduce the load on your mind in the first place.
References
[1] Nasti, L., Michienzi, A. and Guidi, B., 2020, October. Discovering the impact of notifications on social network addiction. In International symposium: From data to models and back (pp. 72-86). Cham: Springer International Publishing. Available at: https://link.springer.com/chapter/10.1007/978-3-030-70650-0_5
[2] Hallowell, E.M., 2005. Overloaded circuits. Harvard business review, 11, pp.1-10.
[3] Misra, S. and Stokols, D., 2012. Psychological and health outcomes of perceived information overload. Environment and behavior, 44(6), pp.737-759. Available at: https://doi.org/10.1177/0013916511404408
[4] Kahneman, D., 2011. Thinking, fast and slow. Macmillan.
[5] Wang, Z. and Begho, T., 2024. A review of the impact of decision heuristics on calorie underestimation and the implications for unhealthy eating. Nutrition & Food Science, 54(3), pp.627-636. Available at: https://www.emerald.com/insight/content/doi/10.1108/nfs-08-2023-0199
[6] Inzlicht, M. and Friese, M. (2021) ‘Willpower is overrated’, Behavioral and Brain Sciences, 44, p. e42. Available at: https://www.cambridge.org/core/journals/behavioral-and-brain-sciences/article/abs/willpower-is-overrated/A226C68E100477F27D0099221F814E25