Albert Michotte and Attributions of Causality

In 1946, Professor Albert Michotte (1881-1965) of Louvain University in Belgium first reported a series of dexperiments on the perception (now called attribution) of causality. Inspired by the philosopher David Hume and others, Michotte devised an elaborate machanical apparatus that allowed him to manipulate the animation of two objects on a projection screen. Both could move left and right at various speeds and with various delays. Small variations in their movement produced large variations in the way his subjects described what they saw. Sometimes the description would be entirely factual, for example, "The ball on the left moved from left to right about 20 cm, then stopped for about 3 seconds. Then the ball on the right moved about 10 cm from left to right and stopped." At other times the description included words attributing motivations, emotions, age, gendereand relationships between the two objects, for example, "The little ball is trying to play with the big ball, but the big ball doesn't want to play so he chases the little ball away. But the little ball is stubborn and keeps bothering the big ball. Finally, the big ball gets mad and leaves."

Below are four simulations of Michotte's experiments. Please try each and ask yourself to describe what you see. Why did you choose that description? What do they tell you about human tendencies to attribute human and non human causes to such simple events?

Prepared by Warren Thorngate, Professor
Psychology Department, Carleton University
Ottawa, Ontario, Canada K1S 5B6
e-mail =
27 January 1997