Thinking in sevens


Categories and lists help us to make better sense of a complex world. But they must be chosen carefully.

On the first day of Christmas, my true love sent to me The One Minute Manager, by Kenneth Blanchard and Spencer Johnson. I thought she might be trying to make a point.

On the second day of Christmas, my true love sent me The Two Minute Motivator. A touch of desperation here, I thought.

But from the third day of Christmas on, the task became easier. I was pleased to receive Michael Porter’s three generic strategies – cost leadership, differentiation and focus. On the fourth day, she presented me with the Boston Consulting Group matrix. There are four types of business in the firm’s portfolio – cows, stars, dogs and question marks.

On the fifth day, back to Michael Porter again, for the five forces of buyers, competitors, suppliers, entrants and substitutes. On the sixth day, who better to turn to than Jack Welch, for the six sigmas. And on the seventh day she pointedly drew my attention to Stephen Covey’s Seven Habits of Highly Effective People. And like highly effective people, she stopped at seven.

The literature of business and the tool kits of consultants, are full of lists. Most of these lists are between three and seven items long. Less than three is too few to have the weight of a proper list. Stephen Covey would have done much less well if he had written The Two Habits of Highly Effective People.

But John Maxwell, author of 21 Indisputable Laws of Leadership and The 17 Essential Qualities of a Team Player, erred in the other direction. Seven is the longest list most people can manage. Try to write down the ten commandments. When I made this a Christmas Party game, almost everyone got stuck at eight or nine. Perhaps Moses was leading an unusually intelligent group to the Promised Land. At any rate, the later church trimmed its prohibitions to the seven deadly sins.

Seven sins, seven habits of highly effective people. Seven seas, seven wonders of the world, seven ages of man, not to mention the seven success factors of Tom Peters and Robert Waterman. And there are seven colours in the rainbow.

Our human instinct is to construct lists and impose categories, even where there are no natural categories. And these lists we use are typically between three and seven items long. Neurophysiologists are beginning to understand why. We have a ‘working memory’ rather like the desktop on your computer, which contains the things you are dealing with right now.

The job of the business guru is to find lists of between three and seven items that enable clients to categorise a complex world in an ordered way. That doesn’t mean that any old categorisation will do. I once spent a session with a company which was debating how they should apply the concepts which had just presented by their expensive consultants. Was the company a hunter or a gatherer? Were its customers empty-nesters or surfers?

They couldn’t do it. They couldn’t do it because the consultants’ categories simply didn’t match the way these managers instinctively saw their business or their customers. Categorisation is inevitably rough and ready. We describe both blood and a pillar box as red although we know perfectly well that blood and a pillar box are actually different colours. The similarity seems more important than the difference.

So are our categories innate, or the product of our culture and environment? Some anthropologists tested this issue by showing paint swatches to primitive tribes with simple languages. They discovered that almost every language distinguished white, black and red. The fourth and fifth colour words were always either green or yellow. If a language had as many as six colour words, it had a word for blue. And if it had reached the stage of seven colour words, the language had a word for brown.

Although there are very many ways in which colours could be categorised, the ways in which humans do it are more or less independent of their culture or their language. There are some kinds of description that just somehow feel right to us and others don’t.

Seven colour words seem to be enough. You can describe anything you can see with seven colours. English, with far more words than other languages, has concepts like amber and magnolia, which are muddy hybrids of existing colours. You can have too many categories to guide you in your choices, as you know when you go to a paint shop in search of green and the salesman asks whether you were looking for pistachio or spring grass. Or too few: it is restricting to have to describe either the physical world or the business world in terms of black and white. On this eighth day of Christmas, make a resolution to review your categories.

Berlin, B & Kay, P Basic Colour Terms: Their Universality and Evolution (1969)

Miller, G The Magic Number Seven: Psychological Review (1956)

Porter, M. Competitive advantage (1985)


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