Willpower kicks in when there is a gap between what we want (donut) and what we are engaged in (diet). Exercising willpower in one instance, like saying no to that donut in the morning, reduces our ability to exert self-control later in the day. So instead of being rewarded for our resistance, our willpower takes a nap and bad decisions creep in.
The interesting twist to ego depletion is how our work or lifestyle is hindering our willpower. Participating in difficult cognitive tasks, like making big decisions, solving problems, etc. throughout the day exhausts our capacity to resist temptations. We become passive and make more impulsive decisions that fall out of line with our true values.
Related to ego depletion is decision fatigue. It’s the deteriorating quality of decisions made by us after already making a series of decisions. We’re constantly trying to make the best decision possible in each situation. As our brain calculates outcomes, weighs values, and processes details, each decision hurdle we encounter drains our ability to make smart decisions. Counterproductive, right?
But the fight for willpower begins at breakfast time! When we're trying to eat healthily yet give into those tempting donuts, it makes it hard for us to maintain our resolve. In fact, engaging in one self-disciplined act—like choosing salad over fries—weakens our ability to do so again later in the day. And this isn't just because of a simple lack of energy - say hello to decision fatigue! Decision fatigue can be loosely defined as the deterioration of quality over successive choices.
What do you think will happen when we make all these decisions during an average workday? It starts pretty easy with minor choices here and there, but things ramp up quickly. Inevitably by 3 o'clock, we're exhausted from all the difficult cognitive tasks required throughout the day. We're passive and start making impulsive decisions that aren't aligned with who we are - whether you mean to or not!
Want to learn a bit more? Check out Dan Gilbert: Why we make bad decisions.