If you run up a long steep incline, it doesn’t take very long before you burn through the energy stored in your muscles and find your legs turning to rubber. We learn this at a relatively early age, and as a result, some of us make it a habit to avoid running up steep inclines.
What you might not realize is that this exhaustion, this depletion of fuel, happens in the exact same way when you exert yourself mentally.
Your brain, like your muscles, runs on glucose. Give your brain a mental workout and your ability to focus, or demonstrate what we call ‘will power’, is spent as well.
This was proven out in a well-known experiment done by psychology Professor Roy Baumeister and his team at Florida State University. They conducted a test where people where randomly assigned to eat either radishes or freshly baked chocolate chip cookies. The radish eaters were instructed to resist eating the cookies. In this case, the noble radish eaters were able to exert enough will power to avoid the cookies 100% of the time.
Both groups were then presented with a series of problems that required extreme eye and hand coordination. The radish eaters gave up noticeably sooner — their focus was about 10% shorter.
In this and in other experiments, Baumeister was able to show that the more often and more recently you resist a desire, the less likely you’re able to complete the next tough task that comes along. This might explain why you were able not to eat those cookies your workmate brought in at lunchtime, only to find yourself with no energy to scrub the bathroom that evening.
Interestingly, will power seems to work just like your leg muscles when you tackle a hill. At some point you run out of gas. And you only possess one store of glucose that both your brain and body share in common.
Luckily people can choose to conserve their glucose and hang onto some will power, and so for this reason we are not necessarily reduced to mush after a series of extremely temping situations.
Not only that but one can build their will power by practicing restraint in four key areas: thought, impulse, feeling control and task performance. The muscle analogy holds up, the more you exercise your will power the better you become at resisting whatever temptation might befall you.
It’s therefore not surprising to discover that the ability to demonstrate will power along with intelligence are the only two reliable predictors about a person’s success measured across a variety of areas including, relationship, happiness, and income generation.
Editors note; don’t try running up a hill with a quart of Hagan Dass in your hand; none of us have enough reserve glucose to pull that one off, not even the most sanctimonious radish eaters...