Psychology_____________________

not necessarily conscious. TS;o person who
has them may be unaware oi their naiure
and they are thus homelimes paradoxically
referred to as 'unconscious ideas/

Instincts are wishes in this sense, and the
sexual and nutritive instincts in their vari-
ous forms are important in determining con-
duct. The wish to conform to the social code
of ethics is called the 'censor/ for the reason
that it conflicts with and often represses un-
ethical wishes, notably those based on the
sexual instinct. The conflict between the cen-
sor and a repressed wish may lead to a dis-
social ion of the personality, in which each
of the conflicting tendencies is expressed in a
portion of the personality. Such an individual
is persistently inconsistent. The phenomena
of hysteria, 'shell-shock,' and many nervous
disorders are of this form. Repressed wishes
are normally partially realized in the con-
tent of dreams; in the dream-state, as in
reverie and hypnosis, the censor is weakened.
The nature of repressed wishes can often be
arrived at by the method of psycho-analysis,
a method in which the behavior of the in-
dividual under shrewd but sympathetic ques-
tioning his inadvertent admissions, the con-
tent of his dreams, and many other symp-
toms of conflict are ptaced together by the
expert clinician to give the information that
the censor tends to repress,

Mental Teats.—The mental test is a simple
procedure for a quick determination of the
degree of some human capacity. In a mental
test the subject is given under standard con-
ditions a simple task to perform rind the de-
gree or quality of his performance is noted.
It is often impossible to define any general
capacity of which tlie test is diagnostic. Ex-
cept as they bear on intelligence, the use of
tests has not as yet contributed greatly to a
knowledge of the fundamental human capaci-
ties. A very great variety of tests have been
invented and used experimentally. There are
tests of motor capacity (speed of tapping
with pencil, accuracy of aiming with a pencil,
steadiness of the hand), of sensory capacity
(visual and auditory acuity, discrimination
of brightnesses, colors, tones, and weights),
of concentration (counting dots on a paper,
crossing out all the a's on a page of pi, per-
forming disparate activities simultaneously),
of description and report (including the tests
of fidelity of report which bear on the relia-
bility of testimony), of learning (repeated
tracing of a design by seeing the hand and
pencil only in a mirror), of memory, of sug-
gestibility, of imagination (seeing images in

J3860__________________________Psychology

I ink - Mots, supi living missing words in a
| t'*xi)- of LOW of information, and of gen-
eral iniel!i,i;t-iice.

Intelligence is the capacity of an individual
adequately to adjust his behavior to new
situations. It is a general ability, independent
of the nature of the particular novel situa-
tion, and appears as a constant factor in a
given adult individual. In childhood intelli-
gence develops steadily from infancy to adol-
escence. In the early years the development
of intelligence is the most marked mental
change that occurs; in adulthood almost all
development is an advance in specific abilities
and knowledge whkh is limited only by a
maximum of intelligence already achieved.
Since nearly all mental tests require adjust-
ments to novel situations, it follows that in-
telligence is conducive to success in mental
tests, no matter what their specific nature,
and that, conversely, any mental test may
in part measure intelligence. Hence intelli-
gence is ordinarily not measured by any
single test, but by a combination of many
tests. However, no combination of tests can
more than partly measure the intelligence.
Psychology has as yet attained to no more
definite conception of intelligence. The sanc-
tion for the concept lies snlely in the fact
that it works for progress both in the prac-
tical use and in the scientific development of
mental tests, and that there is as close agree-
ment between the results of intelligence tests
and individual estimates of intelligence as
there is between the various individual esti-
mates themselves.

The principal method for testing intelli-
gence is that of the Binet scale, which has
passed through several revisions and is now
in wirle practical use in the tenting of chil-
dren. The scale in its latest form consists of
a graded series of ninety simple tests \vhich
are grouped in the series anording to the
age at which the developing intelligence of a
normal child is adequate to them- The scale
is administered by determining the level of
difficulty ut which the subject is unable to
'pass* the tests. A child who pusses all the
tests normal to bix years of age, and fails on
half of those for the seventh year and all of
those for the eighth year has the intelligence
of the 'average* child of wven and a half
years, or, in technical terms* a 'mental age'
of seven and a half. The tests run from the
third year on through the fourteenth year
to groups of tests for 'average adults' and for
'superior adults.' The mental age of average
adult is considerably less than sixteen years.