The Science Behind Mental Overload and How to Avoid It (the overload, not the science...)

A subject that's been talked about increasingly over the last few months is burnout among IT workers. There was a large and positive response to Stephen Nelson-Smith's presentation on the subject at Devopsdays Tel Aviv in October 2013, and again to Mike Preston's ignite talk at Devopsdays London in November.

They were both roundly praised for their courage in speaking publicly about their own burnout, but more than that they encouraged other people to share their own experiences. And the more people speak up, the less the stigma, and the more clearly we see the magnitude of the problem.

I don't think it's an overreaction to say that burnout is not an occasional unfortunate event, but rather it is a serious and frequently-occurring occupational hazard amongst knowledge workers in the tech industry and elsewhere. Just as athletes have to take especial care of their bodies, and both accept and try to reduce the occupational risk of injury, so we as knowledge workers must take equally good care of our minds. We need to ensure that our minds are trained and fit for the work we give them. We need to design and adhere to sustainable working habits and procedures. And we need to be ever vigilant for signs of mental stress or exhaustion, because they are very very common.

Academic psychology has a lot to say about how we may create optimal working conditions for our mighty but fragile brains. This article explores how cognitive hard work and effortful self-control interact and combine to deplete our mental energy and leave us prone to impaired intellectual performance and unwise decision-making.

Self-control and deliberate thought are both types of mental work, and draw from the same limited budget of mental energy. In his book, "Thinking, Fast and Slow" (Penguin, 2011), Nobel laureate psychologist Daniel Kahneman gives an example illustrating this, in which self-control refers to exerting the effort to walk faster than one's natural pace, whilst trying to do some serious creative thinking. He found that walking at a leisurely pace, which can be maintained automatically with no self-control effort, aids thought; deliberately maintaining a faster pace, however, impacts on the ability to make serious cognitive effort.

This effect isn't only apparent when we overload with simultaneous mental exercises; it also holds true with successive tasks. Kahneman describes experiments conducted by Roy Baumeister, which showed that efforts of will are tiring. Following one mentally challenging task, of cognition or self-control, we are less able - or willing - to undertake and succeed in another challenge of intellect or self-control. This effect is known as "ego depletion". Ego-depleted people more readily acquiesce to the urge to give up on a demanding task. And it holds true for a range of combinations of tasks: tests of emotional self-control followed by tests of physical stamina, resisting temptation followed by hard cognitive exercises, among others. Moreover, the list of activities and situations shown to deplete self-control is even wider, including deliberately trying not to think of certain things, making difficult choices, being patient with the bad behaviour of others and overriding our prejudices. All these draw on the same budget of mental energy, and that budget is finite. However, it seems that it's motivation that gets reduced, more than actual mental energy. Unlike with cognitive load - which really does reach hard limits - with sufficient incentive, people can override the effects of ego-depletion.

Out of the lab and back in the real world of burnout, this is most readily applied to the self-control required to make wise choices and not give in to the urge to do dumb things. Experiments have shown that when the brain is heavily taxed by cognitive effort, it becomes much harder to resist temptation. In the work environment maybe that temptation is to slack off, check email, play games, read something irrelevant (and less effortful), eat unhealthy foods, or turn to potentially addictive temptations like drink, drugs, smoking, porn and so on. And when a person is suffering from stress, anxiety, depression - all the uncomfortable mental states that go with burnout - they will often try to "self-medicate" with the same kind of things; to avoid those painful feelings by way of control strategies, typically involving distraction or numbing, which almost certainly make them feel worse, and playing right into that depleted ability to resist temptation, resulting in a damaging feedback loop.

Interestingly, when we speak of "mental energy", the word energy isn't just a metaphor. It's been shown that in cognitive effort (and efforts of will), the brain consumes a substantial amount of glucose. Kahneman uses the analogy of "a runner who draws down glucose stored in her muscles during a sprint", and Baumeister's work has further confirmed that ego-depletion can be cured in the short term by ingesting glucose.

Unsurprisingly, in addition to cognitive effort and hunger, our mental energy is also depleted by fatigue, consumption of alcohol and a short-term memory full of anxious thoughts. There's a paradox here, in that there's a danger that some of the guidance around avoiding overload and burnout - eat well, sleep enough, don't work too long, don't drink too much, don't worry - is so damn obvious and well known that it's actually very easy to ignore (There's another interesting issue going on here - Akrasia: knowing the right thing to do and still not doing it - but I plan to write about that separately, so I won't go into it in this article.). And yet it's fundamental to our personal and professional wellbeing - our vital intellectual resources are finite and need to be stewarded wisely and replenished often. This is why I'm finding it so interesting and helpful to understand the science behind these things. It makes them feel more real, more serious, and less like something our parents told us years ago and we promptly ignored.

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