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We are heavily influenced by numbers. Just how much might surprise you – and I’m not referring to superstition, even though it has led to the disappearance of the number 13 from hotels the world over. Salon recently ran an extract from Alex Bellos’ new book The Grapes of Math: How Life Reflects Numbers and Numbers Reflect Life, and I find it fascinating how our brains are easily swayed by the appearance of a 9 or 0.

Bellos highlights the relationship we have to numbers and how we can be easily manipulated when it comes to shopping. We are all aware that retailers routinely use prices that end in 99c rather than a round number. He highlights the example of a Southern Brittany restaurant that had five pizzas on the menu. When one of the pizzas was reduced in price to €7.99, its share of sales rose from a third of the total to a half. All it took was one cent to make a difference.

We also tend to view large round numbers as being more expensive than a precise one that is actually higher. Our psychology tends to assess it as being more carefully thought through, and therefore fairer. So if you’re selling your house, you’re better off putting the price at $431,935, rather than $430,000. The influence of numbers on our decision-making goes much further. In another study, experienced German judges rolled dice loaded to make up a total of either 3 or 9, having read an account of a shoplifting case. Those that rolled a 3 handed down a sentence on average of five months prison. Those that rolled a 9 were harsher, dishing out eight. Logic says that shouldn’t happen. It’s been said here before: reason leads to conclusions, emotion leads to action.

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Kevin Roberts

Kevin Roberts is founder of Red Rose Consulting; business leader and educator; author and speaker; adviser on marketing, creative thinking and leadership.


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