Self-regulation is our capacity to override or to alter what feels like a natural or instinctive response to a certain stimulus.

At the core of what keeps us civilised as humans is our capacity firstly to define desirable or agreeable responses that are socially acceptable to certain stimuli that occur to us and to regulate our behaviour in the face of that stimuli. We all have agreed standards of behaviour. That’s what makes us reasonably culturally homogeneous in our various countries or societies.

The strength model of self-regulation stipulates that we have limited internal regulatory resources to manage that self-regulation (Baumeister, 2014). When we initially resist a particular impulse, like early in the day it’s pretty easy but come late in the day, the same stimulus might actually be much harder to resist.

A simple example might help to demonstrate.

You’ve made a resolution to cut down on sweet treats as they’re going straight to your waistline. You’re finding this easier said than done and a typical day might look like this. Around

10.00am – you have your first urge for the day to eat something sweet with a cup of tea or coffee. That leftover cake in the fridge is tempting, but you pass at this time. It took some discipline, but you figure you can have an early lunch and you’ll be fine. So you have a coffee and get back to work.

12.00pm – lunch was a salad, which while tasty, has left you feeling a little unsatisfied and with a slightly salty taste in your mouth. Something sweet would be perfect. That cake would hit the spot. No, you manage to resist the temptation. It took some doing, but you’re still on track.

3:00pm – when you walk past the fridge, it’s much more difficult to resist. You tell yourself that you won’t make it until dinner and if you do some exercise later, you’ll be fine. So you have a slice. It tastes okay, but it’s not worth the grief that you then proceed to give yourself.

The point here is that during the day, each time you’ve resisted eating the cake, you’ve engaged internal regulatory resources to prevent you.

The strength model of self-regulation basically says that, given that you’ve used up some of your resources to avoid the temptation of eating the cake during the day, you have less resources available to resist late in the day. This is what’s referred to as ego depletion. The more resources you employ to resist temptation, the more your ego becomes depleted.

Interestingly, the more resources you use to resist temptation effectively, the more likely you are to engage in risky behaviour (Fischer, Kastenmüller and Asal, 2012).

That’s also why later in the day, you’re more inclined to engage in online activities that are not particularly productive; like getting caught by click bait websites, whether shopping, gossip, gambling or pornography. Vices are more likely to grab you late in the day if you’ve been resisting them throughout the day.

(As an aside; from a risk management perspective, if you’ve used a lot of regulatory resources to resist temptation, ie you are in a state of ego depletion, then this is not a good time to be considering taking risk, because in this state, you’re generally more likely to engage in more risky behaviour.)