Turning the Bell Curve Upside Down

In “The Shape of Things to Come” Daniel H. Pink argues that the bell curve or normal distribution discovered during the 19th century statsitcal renaissance is losing its validity. More and more parts of the statistical world are distributing themselves as ‘well curves’, high on the ends and low in the middle. For examples he gives wage distribution in the U.S. (growing at the top and the bottom), consumer electronics (miniturization of screens and the gigantism of home theaters), and business (mega-corporations and the single entrepreneur). He concludes:

Of course, not everything we can measure conforms to this new shape. In national politics, the fastest-growing affiliation is Independent. Diversity and interracial marriage are rendering the old bimodal and trimodal racial categories irrelevant. Yet almost everywhere we look closely, we find ourselves staring down a distributional well. The implications are huge: insurers, marketers, and policy-makers may be basing decisions on faulty premises about what is normal. They’re assuming a vibrant center - Middle America, middlebrow tastes - when the action has migrated to the edges. The 180 from bell curve to well curve has turned their logic on its head.

Galton and his contemporaries believed that conditions would deviate from the bell curve only during periods of transition. Every age, of course, supposes it is living through a unique era of profound change. But in our case, the conceit might actually prove true. The madness of our times might simply reflect our stumbling effort to revert to the mean. Either that or one of the world’s eternal verities is less eternal than we supposed. This deviation may turn out to be anything but standard.