I never really thought of my decision making capacity as something that gets depleted by using it. I’ve certainly experienced that ‘brain dead’ state where making decisions seems hard, but I’ve always associated that with simply being tired, and everything is hard when I’m tired (well, except sleeping).
But a better way of thinking about our capacity to make decisions, is that it’s like a muscle. Exercising it helps to improve its capacity, and using it means it gets tired and needs recuperation.
In 2011 Shai Danzigera, Jonathan Levavb, and Liora Avnaim-Pessoa published research about judicial parole decisions after studying 1,112 rulings over 10 months. These were experienced judges, used to making hard decisions that may have a profound effect on peoples lives. But it seems even they suffer from decision making fatigue.
Apart from the details of case, the researchers knew the order and time the prisoner appeared in front of the parole board, along with their break times and the outcome. They summarise the results in a very revealing graph:
The vertical axis shows the proportion of favourable decisions, a higher value means a higher proportion were given parole; along the bottom is the position or order of the hearing, and the small circles are food breaks – breakfast, late morning snack and lunch.
In summary – a prisoner seen just after a food break, has a much higher chance of being granted parole than a prisoner seen just before a break, even if their offense and record are very similar. Judges are human, and even their decision making ability, as practiced as they are, depletes. What does that mean for the rest of us?
Exercising our self control, making decisions or otherwise using up energy erodes our decision making capability. Being forced to make decisions in this state pushes us towards taking the easy or safe option (denying parole is a ‘safer’ option than allowing it) – and we often don’t realise it.
I’ve heard many times that good leaders have the ability to make fast decisive decisions. Don’t let your ego fool you into that trap when your decision ‘muscle’ is tired. Good leaders make good decisions, and one of them might be to take a break!
P.S. I highly recommend the book by Roy F. Baumeister and John Tierney, “Willpower: Why Self-Control is the Secret to Success”, my inspiration for this post.