Page:Popular Science Monthly Volume 59.djvu/286

276 of place. In the other case I pulled a hook out from a catch but he yanked at the bar to which the hook was attached and so jerked the latter free.

It might be that although the monkeys did not succeed after tuition where they had previously failed, yet they attempted acts which they had not previously attempted. This is not the case, however. There were no signs that the monkeys tried more after tuition to do the things they saw me do than they did before. Their behavior was unmodified by the tuition save that in general they tried less.

It may be objected that the acts I failed to teach the monkeys were not consistent with their make-up, that a monkey might be very intelligent and still not manifest his intelligence by depressing levers, unwinding wires or pulling off loops, that monkeys might be able to learn to do certain things from seeing them done and still be unable to learn the particular acts needed in these experiments. But as a matter of fact, these particular acts were quite natural for the monkeys, quite in accord with their interests and propensities. They learned by the typical animal method acts of the same general sort, e. g., to open boxes and operate the mechanisms throwing food into their cages by pulling bars around, unhooking hooks and pulling at strings. And often the very same act with which I tested one monkey in the experiments just described had been learned by another through the repetition and selection of a chance success. Thus No. 1 learned of himself to unwind a wire though No. 3 failed to do so after seeing me do it 30 times.

The systematic experiments designed to detect the presence of ability to learn from human beings are thus practically unanimous against it. So too was the general behavior of the monkeys, though I do not consider the failure of the animals to imitate common human acts as of much importance save as a rebuke to the story-tellers and casual observers. The following facts are samples: The door of No. 1's cage was closed by an iron hoop with a slit in it through which a staple passed, the door being held by a stick of wood thrust through the staple. No. 1 saw me open the door of his and other cages by taking out sticks hundreds of times, but though he escaped from his cage a dozen times in other ways he never took the stick out and to my knowledge never tried to. I myself and visitors smoked a good deal in the monkeys' presence but a cigar given to them was always treated like anything else.

The following is a sample of the tests of the monkey's ability to learn to do a thing from being made to do it: A box was arranged with its door held closed by a bar of wood held in position in a slot. When it was pushed back an inch and a half further into this slot the door could be opened. It was fastened so that it could not be pulled out from the slot altogether. The only way to get the door open was