It’s a story known by few...the most popular personality profile of all time and the improbable duo who created it.

In the early 1940s, Edward N. Hays and Associates was a successful consultancy specializing in workplace aptitude testing. The tests quantified a worker’s intelligence and personality in order to match them to the job best suited to their profile. There were hundreds of such tests on the market at the time. For sales people there were tests for ‘gregariousness’ and ‘on your feet thinking’. For executives... To learn more, download the full paper.