"all keyed up". So far as known, the
organic response (including the adrenal secretion) is the same in
these various instances of excitement: anger, fear, zeal and so on.
When an individual is in this organic state, his muscles will work
harder and longer than is otherwise possible; and thus are explained
those remarkable cases of extraordinary strength and endurance in
great emergencies, as in escaping from a fire or from a bombarded
city.

The fear-anger state of the organism, being certainly a state of
preparedness for attack or defense, suggests the following
generalization: "Any emotion represents internal preparation for some
type of overt action." This holds good, at least, for food appetite
and sex appetite. Regarding the other emotions, we know too little of
the internal responses that may occur, to judge whether or not they
have any utility as preparatory reactions.

"Expressive Movements," Another Sort of Preparatory Reactions

Though we know little of any internal response in many of the
emotions, we almost always find some characteristic external movement,
such as smiling, scowling, pouting, sneering, sobbing, screaming,
shouting or dancing. By aid of such "expressive movements" we are
sometimes able to judge the emotional state of another person. But
what is the sense of these movements? At first thought, the question
itself is senseless, the movements are so much a matter of course,
while on second thought they certainly do seem odd. What sense is
there is protruding the lips when sulky, {127} or in drawing up the
corners of the mouth and showing the canine teeth in contempt? Perhaps
they are just odd tricks of instinct--for we agreed in the preceding
chapter not to assume all instinctive responses to be useful. Darwin,
however, after studying a great many of these expressive movements,
both in men and in animals, reached the conclusion that, if not of
present utility, they were survivals of acts that had been useful
earlier in the life of the individual or of the race.

Shaking the head from side to side, in negation or unwillingness,
dates back to the nursing period of the individual's life, when this
movement was made in rejecting undesired food. Directly useful in this
case, it was carried over to analogous situations that aroused the
child's reluctance.

Showing the teeth in scorn dates back, according to Darwin, to a
prehuman stage of development, and is seen in its useful form in
animals