and said "We learn _only_ by
doing". For human beings, at least, learn also by observing.

The "insight" just spoken of consists in observing some fact--often
some relationship--and the value of insight in hastening the process
of learning is a proof that we learn by observation as well as by
actual manipulation. To be sure, observation needs to be followed by
manipulation in order to give practical mastery of a thing, but
manipulation without observation means slow learning and often yields
nothing that can be carried over to a different situation.

Learning by observation is typically human. The adult's superiority in
tackling a maze may be summed up by saying that he observes more than
the child--much more than the animal--and governs his behavior by his
observations. The enormous human superiority in learning a simple
puzzle, of the sort used in experiments on animals, arises from seeing
at once the key to the situation.

A chimpanzee--one of the most intelligent of animals--was tested with
a simple puzzle box, to be opened from outside by turning a button
that prevented the door from opening. The device was so simple that
you would expect the animal to see into it at once. A banana was put
into the box and the door fastened with the button. The {318}
chimpanzee quickly found the door, and quickly found the button, which
he proceeded to pull about with one hand while pulling the door with
the other. Without much delay, he had the button turned and the door
open. After about three trials, he had a practical mastery of the
puzzle, showing thus considerable superiority over the cat, who would
more likely have required twelve or fifteen trials to learn the trick.
But now a second button was put on a few inches from the first, both
being just alike and operating in the same way. The chimpanzee paid no
attention to this second button, but turned the first one as before,
and when the door failed to open, kept on turning the first button,
opening it and closing it and always tugging at the door. After a
time, he did shift to the second button, but as he had left the first
one closed, his manipulation of the second was futile. It was a long,
hard job for him to learn to operate both buttons correctly; and the
experiment proved that he did not observe how the button kept the door
from opening, but only that the button was the thing to work with in
opening the door. At one time, indeed, in order to force him to deal
with th