care for her baby, but an inevitable
and almost invincible tendency to "cuddle it when it cries,
smile when it smiles, fondle it and coo to it in turn."

[Footnote 1: Watson: _Behavior_. H. S. Jennings: _Behavior of
the Lower Organisms_.]

In the last few years, as a result of the observation of
animals under laboratory conditions, there has been increasing
evidence of a large number of specific tendencies to act in
specific ways, in response to specific given stimuli. As no
stimuli are ever quite alike, and no animal organism is ever in
exactly the same physico-chemical condition at two different
times, there are slight but negligible differences in response.
Allowing for these, animals may be said to be equipped with a
wide variety of tendencies to do precisely the same things
under recurrent identical circumstances. The aim of the
experimental psychologist is to discover just what actions
occur when an animal is placed in any given circumstances,
precisely as the chemist notes what reaction occurs when two
chemicals are combined.

While experiments with the human infant are more difficult
and rare (and while it is among infants alone among humans
that original tendencies can be observed free from the
modifications to which they are so soon subjected by training and
environment) careful observers find in the human animal also
a great number of these specific ways of acting. Just which of
the large number of observed universal modes of behavior are
original and unlearned, is a matter still in controversy among
psychologists. There is practically complete agreement
among them, however, with respect to such comparatively
simple acts as grasping, reaching, putting things in the mouth,
creeping, standing and walking, and the making of sounds
more or less articulate. Most psychologists recognize even
such highly complicated tendencies as man's restlessness in
the absence of other people, his tendency to attract their
attention when present, to be at once pitying and pugnacious,
greedy and sympathetic, to take and to follow a lead.

In general, it may be said that man possesses not fewer
instincts than animals, but more. His superiority consists in
the fact that he has at once more tendencies to respond, and
that in him these tendencies are more flexible and more
susceptible of modification than those of animals. A chicken has
at the start the advantage over the human; it can at first do
more things and do them bet