other creature. But his instinctive behavior has not the
hard-and-fast, ready-made character that we see in the insects. Man is
by all odds the most pottering, hem-and-hawing of animals. Instinct
does not lead him straight to his goal, but makes him seek this way
and that till he finds it. His powers of observation, memory and
thought are drawn into the game, and thus instinct in man is
complicated and partly concealed by learning and reasoning.

For example, when an insect needs a nest, it proceeds in orderly
fashion to construct a nest of the pattern instinctive to that species
of insect; but when a man needs a home, he goes about it in a
variable, try-and-try-again {112} manner, scheming, experimenting,
getting suggestions from other people, and finally producing--a
dugout, a tree house; a wigwam, a cliff dwelling--something that
differs altogether from many other human habitations, except in the
fact that it is a habitation and thus satisfies a need which is
undoubtedly as instinctive in man as in the insect.

A fully organized instinct is one where the necessary preparatory
reactions are linked up closely with the main reaction-tendency, so
that, once the main tendency is aroused to activity, the preparatory
reactions follow with great sureness. The main team of neurones is
closely connected with the subordinate teams that give the preparatory
reactions; and these connections do not have to be acquired by
experience and training, but are well formed by native growth. Just
the right preparatory reactions are linked to the main tendency, so
that the whole series of acts is run off with great regularity.

In a loosely organized instinct, the main tendency is not firmly
linked with any specific preparatory reactions, but is loosely linked
with a great many preparatory reactions, and so gives quite variable
behavior, which, however, leads on the whole towards the main goal.

While a creature under the spell of a fully organized instinct is
busy, one driven by a loosely organized instinct may be better
described as restless. He tries this thing and that, and goes through
the kind of behavior that is called "trial and error". A closely knit
instinct, then, gives a perfectly definite series of preparatory
reactions, while a loosely organized instinct gives trial and error
behavior. We shall see later how trial and error furnishes a starting
point for learning, and how, in an animal that can learn, those among
the trial