Why Mental Effort Feels Unpleasant: A Meta-Analysis

Author: American Psychological Association
Published: 5 Aug 2024 - Updated: 8 Nov 2026
Publication Details: Peer-Reviewed | Meta-analysis

Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content

Synopsis

This research is a peer-reviewed meta-analysis published in August 2024 in Psychological Bulletin by researchers from Radboud University and Maastricht University, pooling 170 studies with 4,670 participants from 29 countries. Across 358 different tasks, from learning new technology to practicing golf swings, it found that the harder people had to think, the more unpleasant feelings such as frustration, irritation and stress they reported. The link held for workers, students, athletes and military staff, though it was weaker in studies from Asian countries, possibly because students there spend more time on schoolwork. It matters to teachers, employers and designers of apps, tools and instructions, and is useful for people with cognitive disabilities, brain injury or fatigue conditions, for whom heavy mental demands may be especially draining.*

At a Glance

• 1 - The studies were published in 2019 and 2020.
• 2 - Participants included health care workers, college students and amateur athletes.
• 3 - People still choose effortful activities such as chess when they expect a reward.
• 4 - The authors advise supporting or rewarding people whenever tasks demand substantial mental effort.

Topic Definition

Cognitive Fatigue

Cognitive fatigue is a state of mental tiredness that follows sustained or demanding mental activity, marked by reduced concentration, slower thinking, irritability and a growing reluctance to keep working. Everyone experiences it after long periods of effort, but it can be more frequent, severe and lasting in people with conditions such as multiple sclerosis, traumatic brain injury, long COVID, depression or chronic fatigue syndrome.

Overview

If somebody complains that it hurts to think, they may be onto something, as mental exertion appears to be associated with unpleasant feelings in many situations, according to research published by the American Psychological Association.

"Managers often encourage employees, and teachers often encourage students, to exert mental effort. On the surface, this seems to work well: Employees and students do often opt for mentally challenging activities," said senior author Erik Bijleveld, PhD, of Radboud University. "From this, you may be tempted to conclude that employees and students tend to enjoy thinking hard. Our results suggest that this conclusion would be false: In general, people really dislike mental effort."

Researchers conducted a meta-analysis of 170 studies, published between 2019 and 2020 and comprising 4,670 participants, to examine how people generally experience mental effort. They did so by testing whether mental effort is associated with unpleasant feelings and whether that association depends on the task or the population involved.

The studies used a variety of participants (e.g., health care employees, military employees, amateur athletes, college students) from 29 countries and involved 358 different cognitive tasks (e.g., learning a new technology, finding one's way around an unfamiliar environment, practicing golf swings, playing a virtual reality game). In all studies analyzed, participants reported the level of effort they exerted as well as the extent to which they experienced unpleasant feelings such as frustration, irritation, stress or annoyance.

Across all populations and tasks, the greater the mental effort, the greater the unpleasantness experienced by participants.

"Our findings show that mental effort feels unpleasant across a wide range of populations and tasks," said Bijleveld. "This is important for professionals, such as engineers and educators, to keep in mind when designing tasks, tools, interfaces, apps, materials or instructions. When people are required to exert substantial mental effort, you need to make sure to support or reward them for their effort."

One interesting finding, according to Bijleveld, was that while the association between mental effort and adverse feelings was still significant, it was less pronounced in studies conducted in Asian countries compared with those in Europe or North America. This fits with the general idea that the aversiveness of mental effort may depend on people's learning history. High school students in Asian countries tend to spend more time on schoolwork than their European or North American counterparts and may therefore learn to withstand higher levels of mental exertion early on in their lives, he said.

More important is the real-world observation that despite the aversive nature of mentally challenging tasks, people still voluntarily engage in them, said Bijleveld.

"For example, why do millions of people play chess? People may learn that exerting mental effort in some specific activities is likely to lead to reward. If the benefits of chess outweigh the costs, people may choose to play chess, and even self-report that they enjoy chess," he said. "Yet, when people choose to pursue mentally effortful activities, this should not be taken as an indication that they enjoy mental effort per se. Perhaps people choose mentally effortful activities despite the effort, not because of it."

Article

"The unpleasantness of thinking: A meta-analytic review of the association between mental effort and negative affect," by Louise David, MSc, Maastricht University; Eliana Vassena, PhD, and Erik Bijleveld, PhD, Radboud University. Psychological Bulletin, published online Aug. 5, 2024.

Related Information

• Why Thinking Hard Makes You Feel Tired: A study found people who spent over six hours working on tedious and mentally taxing tasks had higher levels of glutamate - an important signaling molecule in the brain.
• Exercise May Improve Thinking Ability and Memory: American Academy of Neurology guideline shows exercising twice a week may improve thinking ability and memory in people with mild cognitive impairment (MCI).
• A Shoulder to Cry On - Empathy, Thinking & Feelings: Researchers studying empathy in relationships find in the absence of caring, understanding alone does not cut it when stressful situations arise.
• Why We Believe in Gods: Religious Beliefs Not Linked to Rational Thinking: Studies have suggested people who hold strong religious beliefs are more intuitive and less analytical, and when they think more analytically their religious beliefs decrease.
• Brain and Body Conflict Helps Thinking Outside the Box: New study shows physical and psychological ambivalence leads to expanded creativity and open-mindedness.
• Brain Scans Reveal Hidden Shape of Thinking Predicting Learning Better Than Test Scores: New findings point to a new way of integrating neuroscience with education.
• When Negative Thoughts Turn to Depression: Negative thinking is a red flag for clinical depression stopping such thoughts early can save millions of people from mental illness.
• Help Dealing with Bad Memories and Emotions: Researchers studied mechanisms of focusing away from emotion during recollection of personal negative emotional memories like how sad you were or how embarrassed you felt.

More on this topic: Neurological Disorders Publications - Brain Health Publications - Psychological Disorders Publications

Frequently Asked Questions

NOTE: Researched FAQs by Disabled World (DW)

What is a meta-analysis?

A meta-analysis combines the results of many separate studies on the same question using statistical methods, giving a more reliable overall estimate than any single study.

Does mental effort burn more calories?

The brain uses a lot of energy at all times, and hard thinking increases it only slightly. Feeling drained after mental work is linked more to brain chemistry and motivation than to calories.

How can I reduce mental fatigue at work?

Taking regular short breaks, splitting big tasks into steps, limiting interruptions and doing the hardest work when you feel most alert can all help.

Why do some people enjoy puzzles if thinking is unpleasant?

People may value the sense of achievement, social connection or reward that follows the effort, even if the effort itself feels unpleasant at the time.

Is cognitive fatigue a symptom of illness?

It can be. Persistent mental fatigue that is out of proportion to activity is common in multiple sclerosis, brain injury, depression and long COVID, and is worth discussing with a doctor.

How can teachers support students during hard tasks?

Teachers can explain why a task matters, give clear steps, offer encouragement and feedback, and allow breaks, which can make effort feel more worthwhile.

What is cognitive accessibility?

Cognitive accessibility means designing information, websites and services so that people with memory, attention or learning difficulties can understand and use them, for example with plain language and simple layouts.

Does practice make mental effort feel easier?

Often yes, as skills become more automatic they need less effort. The study also suggests that people may learn to tolerate effort through experience.

Insights, Analysis, and Developments

Editorial Note: It is easy to assume that people who take on hard puzzles or demanding jobs must enjoy thinking hard, but this review suggests they usually do it in spite of the effort, not because of it. That has practical meaning for anyone designing forms, software, classes or workplaces: every extra step that makes people think harder carries a cost in frustration, and that cost falls hardest on those with less mental energy to spare. People with conditions such as traumatic brain injury, multiple sclerosis, long COVID or ADHD often describe cognitive fatigue as one of their most limiting symptoms. Clear instructions, plain language, breaks and recognition for hard work are simple ways to make effortful tasks more bearable for everyone.*

Attribution/Source(s): This peer-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally issued as a press release by American Psychological Association and published on 5 Aug 2024. Last updated on 8 Nov 2026. This content may have been edited for style, clarity, or brevity.

* Editorial additions by Ian C. Langtree.