stories from the wilder side of science

1900 Rat on a Detour

In 1690, to the southwest of London, the royal gardeners George London and Henry Wise began laying out a maze. At the behest of King William III, they planted small beech trees to mark out 2625 ft (800 m) of winding paths in the grounds of Hampton Court Palace – paths on which some 330,000 visitors still lose their way every year.

Two hundred years later, the psychologist Willard S. Small used some chicken wire and a wooden board to construct his own Hampton Court Maze – for his lab rats. This researcher from Clark University in Worcester, Massachusetts, got the idea when he was searching for a way of finding out how intelligent rats are. The experiment had to be conducted in a controlled environment, but as far as possible the rats’ behaviour was not to be affected by unnatural conditions.

Since rats have a predilection for winding passageways, Small lighted on the idea of building a miniature labyrinth. In all likelihood, he was influenced by an article he had recently read about kangaroo rats. An illustration in this piece that showed their burrows ‘bore a striking resemblance to the apparatus used in these experiments’, as Small later wrote.

He couldn’t have imagined how far reaching a resonance the contraption he devised for his experiment would have, not just in psychology but in the wider world as well. The rat in the maze came to epitomize scientific research per se, but also became a metaphor for a person who is unable to get his bearings in the labyrinth that is modern life. If you type the term ‘like a rat in a maze’ into an internet search engine, you get literally thousands of hits.

For example, someone out there is claiming that the US government is acting ‘like a rat in a maze’, or a certain Chris says on his website that he feels like one whenever he wakes up on a Monday morning. The site provides a so-called ‘Happiness Formula’ that is designed to stop you from feeling ‘like a rat in a maze’. The image has also spawned an entire cartoon genre – no other piece of apparatus used in scientific experiments appears more often in cartoons than the maze.

The reason for Small copying the Hampton Court Maze in particular had to do with the fact that he looked up the term ‘Labyrinth’ in the Encyclopaedia Britannica and chanced upon a map of the famous English maze. His version was a square measuring 8 ft x 6 ft (2.4 m x 1.8 m) – the Hampton Court Maze is trapezoid in shape. He separated the passageways off from one another with pieces of chicken wire 4 in (10 cm) high. He strewed sawdust on the floor of the maze and put some food in the centre.

Then he introduced his rats to the labyrinth. The first two failed the test because noise in the laboratory spooked them. The third rat, a male, found its way to the centre after 15 minutes, while the fourth took 10 minutes, the fifth 1 minute 45 seconds, the sixth 3 minutes, and the seventh 50 seconds. Each time a rat was reintroduced to the maze, it knew its way around better. Though this might seem a somewhat banal result, it was actually quite astonishing, for it was only when the rat located the food that it learned which of the many routes it had tried to take was the correct one. In other words, it was clear that it had the capacity to memorize where it had turned left or right five minutes previously.

On the basis of these experiments, the psychologist Edward Lee Thorndike formulated his ‘law of effect’, which states that actions (such as discovering the correct route through a maze) that have satisfying consequences for an organism (namely, finding food) are more likely to recur than those that lead to unpleasant consequences. Thirty years later, the psychologist B.F. Skinner was to apply a new set of terms to this basic theory, invent another piece of apparatus that became a favourite with cartoonists, and earn himself much opprobrium with his hypotheses concerning human behaviour.

from "The Mad Science Book", copyright 2010 Reto U. Schneider