The stereotype is that we suddenly capitulate to our chocolate craving once 3pm hits, struggle to work well in the afternoon or evening, and smash the chardies after work because our will has been weakened from exercising self-control all day.
This model – that we have finite self-control that, once depleted, leaves us vulnerable to our automatic impulses and desires (as well as leaving us with the attention span of a gnat) – is one many psychologists have subscribed to.
An afternoon slump in productivity and attention is common and over 200 studies have shown that sustained mental effort or impulse control in one area subsequently leads to “inhibition failures” in another area.
To understand whether the time of day affects our ability to handle mental load and what can be done to assuage our mental fatigue, researchers from the University of Toronto monitored more than 16,000 psychology students over four months as they engaged in voluntary learning and self-testing using an online program.
The researchers tracked what times the students logged into the program, how long they spent in the program and how they performed on memory tests.
“Working under the assumption that our users engage in moderately mentally stressful activities throughout the day, the resource model of self-control would predict that users will be most willing to exert voluntary effort most in the morning and least in the evening,” the authors explained. “The assumption that the general population shows self-control depletion throughout the day is a fairly strong one.”
However, they found that the students worked well at any time of the day or night, provided they took breaks and switched up what they were doing.
“We have strong evidence for within-task declines in performance that emerge after about 50 minutes of continuous performance,” they said, adding there was “only weak or inconsistent evidence that time-of-day impacts performance”.
They also said that their findings demonstrate that energy or self-control depletion is not the cause of the afternoon slump (or chocolate-eating or chardy-drinking to excess).
“Users’ login patterns were steady throughout the day and increased substantially towards the evening, while their session lengths were longest later in the day relative to earlier,” they wrote. “This is the exact opposite of what we would have expected from our predictions derived from the resource model of self-control, where a mentally effortful task should be unappealing later in the day.”
It is not to suggest that we don’t get brain drain, but that it is not for the reason researchers once believed (blood sugar or lack of sleep are another story). To deal with mental fatigue and keep our attention fresh, a popular technique among successful people is chunking.
It’s understood that the human brain can only cope with about four different items at once. ‘Chunking’ is when we break down or group together relevant tasks (into no more than four) to make bite size chunks. The idea is that we tackle one task at a time (spending no more than about 50 minutes on it), before taking a break and moving on to the next chunk.
Entrepreneur and leadership expert, Jurgen Appelo explains that it involves four components:
- Focus on one thing at a time and don’t let yourself be distracted.
- If work takes more than an hour to do, cut it up in chunks that each take less than an hour to complete.
* If you have lots of little things to do, bundle them into bigger chunks that take at least 10 minutes each
- Allow yourself frequent little breaks between the chunks to clear your mind and enjoy your progress and accomplishments.
So if you’re struggling to make it through the day, it’s not because you lack self-control or because it’s 3pm, you may just need to switch it up and chunk down your day, whatever time it is.