For the past two years B. F. Skinner, professor of psychology, has been running a slot machine for pigeons in the Psychological Laboratories under Memorial Hall.

The series of experiments, according to Skinner, deals with the "reward principle," that is, the amount of work a creature will perform in gambling against a future pay-off. Skinner compares this with "the incentive for wage-earning in Man."

Skinner places his pigeons in a small closed box with a button in one wall. The birds must peck at this button at least once every five minutes to be paid off with food. The eager but ignorant pigcon, however, not knowing he will get the same reward with less exertion, will hammer away rapidly for great lengths of time to get his dinner.

The latest bird who is matching his powers of endurance against this one-button bandit is attempting to grow fat, according to latest results, by poker-facedly beating a tattoo of 63,000 pecks in 13 steady hours. The time interval that the bird is working is being lengthened, and Dr. Skinner is attempting to learn when this bird will break down, exhibit signs of mental fatigue, and realize that the gambler's life is not for him.

Another test uses three buttons, two of one color and an odd one. This measures quickness of reaction. Birds hit the center button, and then immediately strike the matching one to win their meal.

This places the operation on a skill, rather than gambling, basis, and the pigeons show their appreciation by registering amazing reaction speeds, up to one-tenth of a second. This makes pigeon-speed "greater than that of apes and equal to humans."

According to Professor Skinner, the most interesting development in his tests from a scientific point of view is the "extinction curve" which registers the petering-off of pecks.

A far more difficult process for the birds comes up when the apparatus is set so that a delay between two pecks is necessary for a meal pay-off. He eventually gets wise to this when he discovers that turning around between the first and second peck, or walking across the eage and back, buys him a free meal.

Another example of feathered intelligence was a pigeon used last year, who was taught to play a seven-note tune on a piano--more than a great many people can do.

Professor Skinner gets his birds, or "organisms" as he calls them, from a local pigeon-breeding farm. He admits pigeons are "notoriously dumb creatures," but admires their steadiness of intellect, or lack of it. The farm gives him surplus white homing-pigeons. They are too easy prey for hawks, but make excellent material for the battle of the button.