What are the nature and varieties of human error? - Chapter 1

What are absent-minded errors?

On an afternoon in 1970 James Reason was boiling some water for a cup of tea, while his teapot was waiting for the water and for the tealeaves. His cat was meowing for his food, and because Reason was a little scared of his cat he decided to feed the cat first. But instead of spooning the cat food in the cat’s bowl, he spooned the food into his teapot.

This slip had a number of interesting properties. Giving the cat his food and setting some tea are both highly automatic, habitual sequences that he did in a very familiar environment (his home). The meowing of the cat did not usually occur, this captured the attention and lead to the slip. This slip seemed to have nearly all the principal characteristics of absent-minded errors:

• Both acts (tea, food) were highly routine, so attention was absent.
• Both the cat’s bowl and the teapot afforded containment.
• There was a change in the routine sequence (meowing) that misdirected the action.

Another example for this kind of slips was when Reason observed his wife making tea. His wife was boiling water and had the teapot open waiting for the water and the tealeaves. But instead of getting tealeaves she reached for the jar of coffee, put some spoons into the pot and added water. Only when the strong smell of coffee came, she noticed the slip. The thing of importance is the way she put the coffee into the pot. James explained that the tealeaves have a pull-off lit and the coffee has to be unscrewed. He came to the conclusion that well-used familiar objects develop a local control zone. This means that when your hand enters the zone (like close to the fruit bowl) is automatically performs an object-appropriate action (pick up an apple).

Aimless periods, like passing the time waiting on a phone call, show us that a lot of our behaviour is under the control of the environment, which in turn leads to unintended actions.

What are strong-habit-intrusions?

Strong-habit-intrusions are actions that are under-specified (due to forgetting, reduced intention etc.), people tend to lean on the actions that usually occur in that particular context. These situations are called strong-habit-intrusions.

The tip-of-the-tongue phenomenon is a state where strong-habit-intrusions occur. We struggle to retrieve the word that we mean, but we can recall all the words that seem similar to it (blockers).