It seems like an iron rule of nature: the longer you do something, the more tired you get.
During the first mile of your daily run, you’re all amped up. You may even run a little too quickly. But after three or four miles—whew. You’re exhausted.
The same thing seems to be true of thinking: the first hour of studying is easy, but after two or three… we hit a wall. We’re mentally fried.
Behavioral scientists have looked for this same pattern, and they’ve found some remarkable things:
- Judges that have been deciding cases all morning seem to get tired and just go with the default judgement by late morning. But, after eating, they seem to get re-energized and make more thoughtful decisions.
- Consuming a sugary drink, like lemonade, can replenish one’s diminished self control.
- Like a muscle, willpower can be increased with practice.
- And so on…
However, I’ve always been a bit skeptical of this line of research. It sounds reasonable, but it seems to be an example of taking a metaphor (“the mind is a muscle”) a bit too far.
All of us have encountered people who seem to gain momentum and energy as the day goes on. Their ability to push through pain and make hard decisions only increases. What’s going on with them? Are they just an exception to the rule? Or does mental energy and self control only decrease in some people and not others?
Well, some recent research has come out showing that the mind does not always act quite like a muscle–fatiguing with use. In fact, according to these researchers, doing a hard task can actually increase performance / energy on a subsequent task.
As Christian Jarrett writes in the BPS Research Digest:
“Exercising self-control leaves you feeling drained. That’s what many of us in the West believe and it’s what we seem to experience – think of the fatigue after a morning spent dealing with difficult clients or focused on spreadsheets on a computer screen. But in Indian culture, there is a widespread belief that mental effort is energising – that the more concentration and self-control you expend in one situation, the more invigorated you will feel for the next challenge.
Psychology has, so far, mostly backed up our Western intuitions. Over 100 studies – nearly all conducted in the West – have shown that participants are less able to resist temptation or exercise mental focus after completing a mentally taxing task, an effect that researchers call “ego depletion”. But now a paper in the Journal of Personality and Social Psychology has tested Indian participants and it shows for the first time a “reverse ego-depletion effect” – the more difficult an initial mental task, the better participants performed on a subsequent challenge.
Exercising self-control leaves you feeling drained. That’s what many of us in the West believe and it’s what we seem to experience – think of the fatigue after a morning spent dealing with difficult clients or focused on spreadsheets on a computer screen. But in Indian culture, there is a widespread belief that mental effort is energising – that the more concentration and self-control you expend in one situation, the more invigorated you will feel for the next challenge.
Psychology has, so far, mostly backed up our Western intuitions. Over 100 studies – nearly all conducted in the West – have shown that participants are less able to resist temptation or exercise mental focus after completing a mentally taxing task, an effect that researchers call “ego depletion”. But now a paper in theJournal of Personality and Social Psychology has tested Indian participants and it shows for the first time a “reverse ego-depletion effect” – the more difficult an initial mental task, the better participants performed on a subsequent challenge.
Belief in the benefits of exercising self-control permeates Indian Culture. Children are taught concentration techniques, such as focusing on a candle flame in a dark room. Regular prayers and meditation are widely encouraged. It’s a cultural view that appears to manifest in education: Indian children have longer class times and spend more time on homework than American children; Indian students spend more time reading books than Americans.
To test how these beliefs and practices might shape the basic psychological processes underlying self-control, Krishna Savani at Nanyang Technological University and Veronika Job at the University of Zurich completed four studies involving hundreds of Indian participants, as well as participants in Switzerland and the US.
The usual procedure was that participants completed an initial easy or difficult ten-minute challenge, such as solving mazes, the Stroop test (naming the ink colour of words denoting a different colour, e.g. “blue” written in red), word searches, or an editing type task, and then they proceeded to second, unrelated task of a similar kind. For example, the first task might be easy or difficult mazes, and the second task might be a Stroop test.
Indian participants who completed a more difficult initial task tended to perform better on the second challenge than Indian participants who completed an easier initial challenge – in other words, reverse ego-depletion. In most cases, Western participants showed the opposite pattern of performance, showing worse results after a tougher initial test, which is the established ego-depletion effect.
Among Indian participants, the more strongly they endorsed the idea that mental effort is energising, the stronger the reverse ego-depletion that they tended to exhibit.
These new findings challenge the established theory in Western psychology that self-control or willpower is like a fuel, that if you use it up in one situation, you will have less left over for the next challenge.
It’s even been suggested that self-control depends on sugar in the body and that you can enhance your willpower by consuming glucose drinks.
But as is so often the case in psychology these days, the story is not that simple. Recently, there have been several failed attempts to replicate the ego-depletion effect, even with Western participants. Doubts have been raised about the links between self-control and glucose. Other studies have suggested that if people believe their willpower is unlimited, then expending self-control doesn’t harm their performance. All this points to motivation as the key factor underlying the exercise of self-control, not some energy-based physiological process.
These new results are in line with the motivation account. They show for the first time that if people believe mental effort is energising, not only is their performance not adversely affected by prior mental demands, but it is actually enhanced.
How malleable are these beliefs? In a final study, Savani and Job tested the effects of manipulating Indian and American participants’ beliefs about self-control. One group read a 600-word article about how exerting willpower is energising, the other group read an article of the same length about how exerting willpower is mentally draining. Then both groups completed two tests of mental concentration in succession.
Participants from India and America who read the energising text showed reverse ego-depletion: their performance on the second task was better if the first task was more challenging. In fact the worse performance on the second task was for participants who read the “exerting willpower is energising” text and then completed an initial easy task. If you believe mental effort is energising, then it seems it is tasks that are too easy that take more of a toll.
The researchers said their results “can be viewed as casting further doubt on claims that ego-depletion is a pan-cultural phenomenon rooted in human biology, and instead supports the argument that motivational factors play a crucial role in determining how strenuous tasks influence subsequent self-control exertion.”
