James Reason, Who Used Swiss Cheese to Explain Human Error, Dies at 86

The story of how James Reason became an authority on the psychology of human error begins with a teapot.

It was the early 1970s. He was a professor at the University of Leicester, in England, studying motion sickness, a process that involved spinning his subjects round and round, and occasionally revealing what they had eaten for breakfast.

One afternoon, as he was boiling water in his kitchen to make tea, his cat, a brown Burmese named Rusky, sauntered in meowing for food. “I opened a tin of cat food,” he later recalled, “dug in a spoon and dolloped a large spoonful of cat food into the teapot.”

After swearing at Rusky, Professor Reason berated himself: How could he have done something so stupid?

The question seemed more intellectually engaging than making people dizzy, so he ditched motion sickness to study why humans make mistakes, particularly in high-risk settings.

By analyzing hundreds of accidents in aviation, railway travel, medicine and nuclear power, Professor Reason concluded that human errors were usually the byproduct of circumstances — in his case, the cat food was stored near the tea leaves, and the cat had walked in just as he was boiling water — rather than being caused by careless or malicious behavior.