As we turn from the objective to the subjective conditions of
deception, we enter the true domain of psychology; for the most
scientific deceiver is he who employs least external aids, and
counts most upon his power of captivating the intellect. Just as we
interpret appearances by the forms they most commonly assume, so it
is our average normal selves that interpret them. A variation in our
sense-organs or in our judging powers will lead to illusion. The
effects of contrast may serve as apt illustrations. When passing
from a dark to a light room the light seems glaringly bright; a hand
immersed in hot water and then in lukewarm water will feel the latter
as cold; when accustomed to the silence of the country the bustle of
the city seems unusually noisy. Fatigue produces similar results.
Fatigue the eye for red, and it sees white light as green; the last
mile of a long walk seems the longest; the last hour of a long wait,
the most tedious. So long as we recognize our unusual condition and
allow for its effects, we are not deceived; but under the influence
of emotion this power is readily lost, as it may be permanently lost
in the insane. The delusions of the insane are often influenced by
misinterpretations of real but abnormal sensations under the guidance
of a dominant idea. On the basis of an anæsthetic skin a patient may
come to believe that he is made of glass or stone; subjective noises
in the ear, due to disturbances of the circulation, are transformed
into the jeers and taunts of an invisible persecutor. But for the
present we will assume that the judging powers do not vary beyond
their normal limits.
In every perception two factors contribute to the result. The one is
the nature of the object perceived, the other that of the percipient.
The effect of the first factor is obvious and well recognized; the
importance of the second factor is more apt to be overlooked. The
sunset is a different experience to the artist from what it is to the
farmer; a piece of rocky scenery is viewed with quite a different
interest by the artist and the geologist. The things that were
attractive in childhood have lost their charm; and what was then,
if noticed at all, considered stupid, has become a cherished hobby.
Even from day to day, our interests change with our moods, and our
views of things brighten with the weather or the good behavior of
our digestive organs. Not only will the nature of the impression
change with the interests of the observer, but even more, whether or
not an object will be perceived at all, will depend upon the same
cause. The naturalist sees what the stroller entirely overlooks; the
sailor detects a ship in the distant horizon where the landsman
sees nothing; and this is not because the naturalist and the
sailor have keener vision, but because they know what to look for.
Whenever an impression is vague, or an observation made under poor
conditions, this subjective element comes to the front. Darkness,
fear, any strong emotion, any difficulty in perception reveal the
same influence. "La nuit tous les chats sont gris." Expectation, or
expectant attention, is doubtless the most influential of all such
factors. When awaiting a friend, any indistinct noise is readily
converted into the rumbling of carriage-wheels; the mother hears
in every sound the cry of her sick child. After viewing an object
through a magnifying-glass, we detect details with the naked eye
which escaped our vision before. In spite of the fact that the answer
in the book happens to be wrong, a considerable proportion of the
class succeeds in reaching it. Everywhere we are apt to perceive
what we expect to perceive, in the perception of which we have an
interest. The process that we term "sensation," the gathering of
evidence by the senses, is dual in character, and depends upon the
eyes that see as well as upon the things that are present to be seen.
Accordingly, the conjurer succeeds in his deception by creating an
interest in some unimportant detail, while he is performing the real
trick before our eyes without our noticing it. He looks intently at
his extended right hand, involuntarily carrying our eyes to the same
spot while he is doing the trick with the unobserved left hand. The
conjurer's wand is extremely serviceable in directing the spectator's
attention to the place where the performer desires to have it.[5]
A call upon the attention in one direction prevents its dispersion
in another. When engrossed in work, we are oblivious to the noise
of the street or even to the knock at the door. An absent-minded
person is one so entirely "present-minded" to one train of thought
that other stimuli go unperceived. The pickpocket is psychologist
enough to know that at the railway station, the theatre, or wherever
one's attention is sharply focused in one direction, is he apt to
find the psychological moment for the exercise of his pursuit. It
is in the negative field of attention that deception effects its
purpose. Houdin, the first of the famous prestidigitateurs (died
1871), gives it as one of his rules never to announce beforehand the
nature of the effect which you intend to produce, in order that the
spectator may not know where to fix his attention. He also tells us
that whenever you count "_one_, _two_, _three_," as preliminary to
the disappearance of an object, the real vanishing must take place
before you say "_three_,"--for the audience have their attention
fixed upon "_three_," and whatever is done at "one" or "two" entirely
escapes their notice. The "patter" or setting of a trick often
constitutes the real art of its execution, because it directs or
rather misdirects the attention. When performing before the Arabs,
Houdin produced an astounding effect by a very simple trick. Under
ordinary circumstances the trick was announced as the changing of the
weight of a chest, making it heavy or light at will. The mechanism
was simply the attachment and disconnection of an electro-magnet, in
those days a far less familiar affair than now. To impress the Arabs
he announced that he could spirit a man's strength away and restore
it again at a moment's notice. The trick succeeded as usual, but was
changed from a mere trick to sorcery--the Arabs declaring him in
league with the devil.
The trick, above cited, of supporting a child in mid-air, was
performed by Houdin at the time when the inhalations of ether for
purposes of insensibility were first introduced. This idea was
in the minds of the audience, and magical effects were readily
attributed to etherization. Accordingly the trick was announced as
"suspension in equilibrium by atmospheric air through the action of
concentrated ether," and so successfully was this aspect of the trick
accepted that protests were sent in against "the unnatural father
who sacrificed the health of his poor child to the pleasures of the
public." In the same way, Kellar introduces a "thought-reading"
performance, by going through the movements of hypnotizing the lady
who assists in the trick; this enables him to present the phenomenon
in a mysterious light, and incidentally his manipulations furnish the
opportunity to connect the end of a speaking-tube concealed in the
lady's hair with another portion attached to the chair. In brief, the
effect of a trick depends more upon the receptive attitude of the
spectators than upon what is really done. "Conjuring," Mr. Triplett
observes, "is thus seen to be a kind of game of preperception wherein
the performer so plays upon the psychical processes of his audience
that the issues are as he desires."
There is, too, a class of tricks which illustrate a process, the
reverse of this; and which depend for their éclat upon making the
issues coincide with the apparently freely expressed choice of the
spectator, while really the performer as rigidly determines the
result as in all other cases. One of the best of these proceeds
by collecting some eight or nine questions prepared by as many
persons in the audience, then placing them in a hat, drawing out
one at random, and finding the answer to the question thus selected
written on the inside surfaces of a pair of slates. The deception
begins in the substitution for the collected slips of paper, of the
same number of slips all containing the same carefully prepared
question; the production of the writing on the blank slate is a
chemical technicality. It is a similar result that is obtained in
forcing a card; or when the conjurer asks the audience to select
one of a group of similar objects, and then himself decides whether
the selected object shall be used for the trick or discarded;
likewise, when a magic bottle is presented from which any desired
variety of liquor may be produced, it is easy to suggest the choice
according to the available possibilities. There is thus an imitation
of the psychological factors as well as of the objective factors
of real experience; and both are utilized in the deceptions of the
professional conjurer.
The art of misleading the attention is recognized as _the_ point of
good conjuring, the analogy of the diplomacy that makes the object
of language to conceal thought; and many appropriate illustrations
of this point may be derived from this field. The little flourishes,
tossing an object up in the air, ruffling or springing a pack of
cards, a little joke--all these create a favorable opportunity, a
_temp_ when the attention is diverted and the other hand can reach
behind the table or into the "pocket." It is not necessary to pursue
further these details of technique; it will suffice to analyze the
points of interest in the chest-and-ring trick described above. Here
the moment for the exchange of the rings is the one which is least
suggestive of its being a part of the performance, and therefore
least attended to. The preparations for the shooting absorb the
attention and allow the introduction of the small table at the rear
to pass unnoticed; while the series of drawings of the chests so
entirely prepare the spectator for the appearance of the last chest
from the one preceding, that he actually sees the chest emerge from
where it never had been.
It is necessary, however, not only to provide an opportunity for
non-attention or misdirected attention, but to be able to take
advantage of it when the proper moment arrives. Here enters the
dexterity alike of pickpocket and of conjurer. The training in
quickness and accuracy of motion, in delicacy of touch, in the
simultaneous perception of a wide range of sense-impressions, are
among the psychological requisites of a successful conjurer. He must
dissociate the natural factors of his habits, actually doing one
thing while seemingly attending to another; at the same time his eyes
and his gestures and his "patter" misdirect the attention to what
is apparently the essential field of operation, but really only a
blind to distract attention away from the true scene of action. The
conjurer directs your attention to what he does not do; he does not
do what he pretends to do; and to what he actually does he is careful
neither to appear to direct his own attention nor to arouse yours.