50 Shades of Grey Matter by Dr Karl Kruszelnicki – Extract

50 Shades of Grey Matter


What’s the link between marshmallows, money and the munchies? Willpower and self-control!

Back in 1968, Walter Mischel from Stanford University in California came up with the now-famous “Marshmallow Test”. It tested self-control in some 600 children aged between four and six.


The kids were each individually offered a treat: a marshmallow, a pretzel, or an Oreo cookie. If they wanted, they could eat the treat immediately. But if they waited 15 minutes and didn’t eat the single treat, they would then be rewarded with an additional treat. As you might expect, the older kids were better at waiting longer.

Looking at the whole group, a small minority didn’t even think about waiting and immediately ate their treat. Most of the kids tried to hold off – and most failed. About one third were able to wait it out successfully for a full 15 minutes and be rewarded with their additional treat.

It was very hard for the kids. Some covered their eyes or turned around so that they couldn’t see the tempting treat, others kicked a desk or stamped their feet on the floor or even pulled their hair to divert themselves from thinking about it.

Others stared into the mirror, or began talking to themselves.

The more they avoided looking at the treat, the more successful they were at waiting the full 15 minutes. Rather than stoically “willing” themselves to stare down temptation, they simply engaged in other activities to avoid looking at the treat. Some sang songs, while others hid their heads in their arms, or prayed to the ceiling. Dr Mischel noted, “In one dramatically effective self-distraction technique, after obviously experiencing much agitation, a little girl rested her head, sat limply, relaxed herself, and proceeded to fall sound asleep.”

Mind you, once they had managed to successfully distract themselves for the full 15 minutes, they didn’t wait any longer and immediately rewarded themselves by eating both treats.


Originally, Dr Mischel had no intention of doing any follow-up. But his three daughters went to the same school as some of the four­-to-six-year-old kids in his study. As part of idle dinner conversation, he would ask his daughters about these kids. As the years rolled by, he thought he could see a link between their ability to wait for the second marshmallow and how well they did in school.

So he then followed up the kids as they grew up (1981, 1990 and 2011). The results were amazing. In the USA, the SAT exams are standardised tests for admission to university, with a maximum possible score of 2400. The students who as kids could wait 15 minutes for their treat had an SAT score that was 210 points higher than those of the children who could wait only 30 seconds. These kids also ended up being more successful and popular at school and at work, and more respected by their co-workers. The ones who couldn’t wait 15 minutes were more likely to have behavioural problems, both at home and in school. They were less likely to have done well at school, less able to deal with stress, and more likely to get fatter and to have more personal problems. They were also more likely to have been arrested, and to have problems with drugs. Dr Angela Duckworth from the University of Pennsylvania found a similar result with eighth-grade students. She gave them a choice between a dollar right then, or two dollars one week later. The ones who could wait also did better at school. Surprisingly, this ability to delay gratification was a much better predictor of the students’ academic performance than their IQ (about two times better).

It’s Not Just Marshmallows

If you can hold out for 15 minutes so that you get two marshmallows instead of one, then in later life you will probably do your homework before watching TV.

Dr Mischel found that children from poor families tended to be worse at delaying gratification. He says, “When you grow up poor, you might not practise delay as much. And if you don’t practise then you’ll never figure out how to distract yourself.

You won’t develop the best delay strategies, and those strategies won’t become second nature.”

But Dr Mischel found a workaround. For example, he taught the kids to pretend that the tempting treat was not really a treat, but only a photograph surrounded by an invisible frame. This simple trick dramatically improved their self-control.


Part of what makes up self-control is your ability to change what you do and think. So it covers how you guide your thoughts and emotions, and how well you perform your duties and tasks.

We used to think of self-control or willpower as being some kind of “moral attribute”, with “stronger” people having more while others had less. But now we think of it as being more like a muscle. It can be overworked and tire out, it can get stronger with exercise, and it can be recharged after a rest and a feed.

First, even though you don’t realise it, you use your self-control throughout your day. Dr Wilhelm Hoffman, currently at the University of Chicago, monitored 200 German adults by getting them to wear a beeper. When the beeper went off, they would report what they were doing at that exact moment. It turned out that his subjects were spending an amazing three to four hours every day simply resisting desires and temptations, by using their willpower and self-control.

Second, willpower is finite, and exists in a single “pool”.

Each day, there are many different desires and temptations that assault you – rational thoughts, irrational emotions, desires to eat or to exercise and so on. But you do not have a separate “pool” of willpower for each of these. Instead, it appears as though you have one single “pool” of willpower that has to cover all the different temptations that confront you.

This “pool” of willpower is not very big. If you use up a lot of willpower in resisting temptation on one task, the amount that you have left to deal with a subsequent, completely unrelated, task is much lower.

Think of willpower as being like a muscle. In a race, athletes might conserve their strength and not use up all of their muscle power early, so that they have some left for a big finish. The same logic applies to willpower.

Third, this depletion of willpower can be halted, or even reversed, by glucose.

Studies have been done in which the subjects had to perform a series of willpower/self-control tasks. As expected, they gradually got worse as they moved from one set of tasks to the next. But if they drank regular lemonade they performed better than people who drank diet lemonade.

Satan – Get Thee Behind Me

In the Bible, the Devil comes to tempt Jesus during his 40-day fast in the desert. Eventually, Jesus says the now-famous sentence, “Get Thee Behind Me, Satan!”

Jesus chose an excellent strategy. If you deliberately remove the things that are tempting you from your immediate environment, then the strength of the temptation is weakened. You do not have an infinite amount of self-control. So if you remove or lessen the temptation, you will be able to spread your limited amount of self-control over a longer period of time.

This strategy is not Rocket Science (but some people might consider it Divine Intervention). It can be learned at an early age, and then be used to lessen temptation. Unfortunately, some people are never taught this.


So what about people who need to exert continual self-control so that they do not overeat? On one hand, they need some glucose to top up their “pool” of willpower. But eating to get their glucose adds to the risk of actually overeating. It’s a vicious circle. That’s part of the reason why diets are devilishly difficult – and why 85 per cent of all diets fail.

The way around this is for dieters to have a lifestyle change. By changing the way they view food and meals, so that they select food that is both healthy and satisfying, they get a fuller tummy, which boosts their willpower and helps protect them from overeating. This is a real win-win situation.

Getting back to Dr Mischel, he has some simple advice on teaching self-control. “We should give marshmallows to every kindergartner. We should say, ‘You see this marshmallow? You don’t have to eat it. You can wait. Here’s how.’”

Sirens – Get Thee Behind Me

We all have different shortcomings, or weaknesses, in our personality. We can’t always fix them, but we can work around them or outsmart them.

If you love a certain fatty food, deliberately try not to buy it in the shop or supermarket. If you succeed, it won’t be in your pantry at home, tempting you. (You should think of this love for fatty foods as an excellent survival tactic, not a “weakness”. It’s a direct result of 200,000 years of evolution, from a time when food was scarce.)

In Greek Mythology, Odysseus (or Ulysses, as the Romans called him) knew that he could not resist the song of the Sirens. He cleverly had his crew tie him to the mast so that he couldn’t obey their haunting song and be lured to his death on the rocks. He also had his crew block their ears so that they could hear neither the Sirens’ song nor his entreaties to release him – and so avoided the Sirens (and Doom).

Excerpted from 50 Shades of Grey Matter by Dr Karl Kruszelnicki. Copyright © 2012 by Dr Karl Kruszelnicki.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Pan Macmillan Australia solely for the personal use of visitors to this web site.


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