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The Wiki Man

The Wiki Man: If you want to diet, I’m afraid you really do need one weird rule

13 April 2013

9:00 AM

13 April 2013

9:00 AM

‘Never play cards with a man called Doc. Never eat at a place called Mom’s. And never sleep with a woman whose -troubles are worse than your own.’ These were Nelson Algren’s Three Rules of Life.

You may have noticed a few more ‘rules of life’ appearing recently. After years of our being advised to drink some forgettable number of units of alcohol every week, a new rule seems to have emerged: ‘Don’t worry much about how much you drink but do abstain from alcohol completely for at least two days in seven.’ The hottest diet of the moment, sometimes called the 5:2 Diet, lets you eat freely except for two days of fasting each week. Other diets focus on total abstinence from carbohydrates, especially sugar.

Something about this black-and-white, binary approach makes sense. For any diet or health regimen to work, it must be based on rules we find psychologically easy to follow. And as the world’s religions have known for thousands of years, abstinence is far easier than the continuous exercise of self-restraint. Or, as the neuroscientist V.S. Ramachandran suggests, humans may not have free will but they do have free won’t.

Let’s consider the old rule of restricting yourself to a maximum number of units of alcohol a week. It demands constant vigilance. It often requires you to stop drinking while drunk. And it is fiendishly easy to cheat: you simply convince yourself that a 25cl glass of 14.7 per cent Chilean Merlot is one unit when it is really three. Better men than us have deceived themselves this way: Immanuel Kant rationed himself to one pipe of tobacco after breakfast; he stuck to his rule, but friends noticed that by the end of his life, all his pipes were enormous. Quantitative rules make self-deceit easier.

Absolute rules (if X, then Y) work with the grain of human nature. We feel far more guilt running a red light than breaking a speed limit. Notice that almost all religious laws are absolute: no food is half kosher; it is or it isn’t. No Old Testament prophet proposed something as daft as the French 35-hour ‘working-time directive’: they invented the Sabbath instead.

In a more complex world weighed down by Big Data, convoluted tax structures and impenetrable legislation, do we actually need more of what religion once gave us: simple, unambiguous, universal absolutes? In law such rules are known as Bright Line Rules: rather than 20 million words of tax law, you simply declare ‘any financial transaction whose only conceivable motivation is the avoidance of tax is by definition illegal’.

Does a complex world need simpler rules? And simpler metrics? The temptation is that because we have gigabytes of data, we feel the need to use all of it. Perhaps all you need is a few bits of the right information?

During the second world war, experts needed to decide whom to train as RAF fighter pilots. Today this would mean a battery of complex tests. Back then they used two simple questions: 1) Have you ever owned a motorcycle? 2) Do you own one now? The ideal recruits were those who answered 1) Yes and 2) No. They wanted people who had been brave enough to ride a motorbike but were sane enough to abandon the habit.

How many of the world’s problems could be solved if we abandoned this pretence of perfect rationality and fell back on simple, heuristic rules of thumb? According to the brilliant German decision-scientist Gerd Gigerenzer, quite a few.

So here’s my heuristic suggestion to improve social mobility. All Russell Group universities should be compelled to reserve 50 per cent of their places for people who have never been on a skiing holiday.

Rory Sutherland is vice-chairman of Ogilvy Group UK.

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