One reason for the problems with the “willpower depletion” theory is that people think it should work like a gas tank. As long as you have gas, you can drive. When it runs out, your car stops, and that’s it.
Obviously, willpower does not work like that, and it would be bad if it did. If it did, you would feel normally and do whatever you wanted, until you ran out, when you would suddenly lose all control.
Now the gas analogy is not totally false, and there are people who do run into a point like that, just like you can run and run until you literally fall to the ground. But that’s not what normally happens, either with running, or with will power.
Instead, you get lots of warning signals when your willpower is running low, and therefore your brain starts telling you to conserve willpower by avoiding activities that seem especially unnecessary or especially difficult.
It also tends to work a bit like money. Money does not work like gas. How many people do you know who literally run out of money, so that they can’t spend a single cent more? Not many. Instead, people become less willing to spend money as they have less left. Similarly, if you are planning to spending $300 on a party for your friends, you might do so fairly easily, but if you go out for dinner with your friends without planning on that, and suddenly they ask you to pay for it, that might be a bit upsetting. In a similar way, if you are planning to work Mon-Fri, it may be easy enough to do so. But if your boss calls you up and tells you that you have to work on the weekend, that might be a bit upsetting, in a similar way.
Basically, it is just really complicated and people who expect to confirm willpower depletion by simplistic testing are just doing it wrong. But it does work like a quantity, and as gwern says, lots of different things will tend to build it up, generally things you feel like doing, so which aren’t using up as much willpower.
One reason for the problems with the “willpower depletion” theory is that people think it should work like a gas tank. As long as you have gas, you can drive. When it runs out, your car stops, and that’s it.
Obviously, willpower does not work like that, and it would be bad if it did. If it did, you would feel normally and do whatever you wanted, until you ran out, when you would suddenly lose all control.
Now the gas analogy is not totally false, and there are people who do run into a point like that, just like you can run and run until you literally fall to the ground. But that’s not what normally happens, either with running, or with will power.
Instead, you get lots of warning signals when your willpower is running low, and therefore your brain starts telling you to conserve willpower by avoiding activities that seem especially unnecessary or especially difficult.
It also tends to work a bit like money. Money does not work like gas. How many people do you know who literally run out of money, so that they can’t spend a single cent more? Not many. Instead, people become less willing to spend money as they have less left. Similarly, if you are planning to spending $300 on a party for your friends, you might do so fairly easily, but if you go out for dinner with your friends without planning on that, and suddenly they ask you to pay for it, that might be a bit upsetting. In a similar way, if you are planning to work Mon-Fri, it may be easy enough to do so. But if your boss calls you up and tells you that you have to work on the weekend, that might be a bit upsetting, in a similar way.
Basically, it is just really complicated and people who expect to confirm willpower depletion by simplistic testing are just doing it wrong. But it does work like a quantity, and as gwern says, lots of different things will tend to build it up, generally things you feel like doing, so which aren’t using up as much willpower.