bodily
movements, are an experience painful even in the recollection.

Movements and contractions due to nervousness are entirely purposeless;
they even defy the most earnest efforts at inhibition. A marked feature
of this type of involuntary action is the contraction of antagonist
groups of muscles, productive of muscular stiffness of the members.

An extreme example of this form of nervousness is offered by the
unfortunate sufferer from stage fright. In this condition the entire
body often stiffens, and purposeful movement of any kind becomes for a
time impossible.

(_c_) _Contractions caused by Special Attention to Certain Members_

Suppose a small boy of sensitive nature to enter a room suddenly, and to
be at once chided for his awkwardness. His body will probably stiffen,
and his awkwardness become more pronounced. Now call his attention to
his hands and tell him he is holding them badly. His arms and hands will
immediately become painfully stiff. Speak of his feet and his legs come
on tension. Whatever member his attention is turned to, the muscles of
that part contract involuntarily.

Photographers sometimes have to contend with this form of involuntary
action on the part of their sitters. When the hands are to be posed the
arms stiffen; so also do the legs, the shoulders, and the neck, each
when its turn comes to receive attention.

Under normal conditions this form of awkwardness is easily overcome.
Sitting for a photograph soon becomes a simple matter. The boy outgrows
the awkward stage and gradually acquires a natural and easy bearing.
Muscular stiffening due to attention to special members is usually the
result of an uncomfortable feeling of being out of one's element, and
ill at ease in one's surroundings. So soon as this feeling wears off the
tendency to this form of stiffness disappears.

(_d_) _Contractions of Muscles due to the Radiation of Nerve Impulse_

A voluntary exertion of some of the muscles of a member sometimes causes
the involuntary contraction of all the other muscles of the part. As
will readily be seen, the exercise then takes place under conditions of
muscular stiffness. This is commonly a feature of the unskilful and
unaccustomed performance of muscular activities. A few examples will
serve to illustrate this type of involuntary contraction better than a
lengthy discussion of the physio-psychological principles involved.

When a novice takes his first lesson in riding a bicy