Psychical

science are called psychiatrists or alienists.

Psychical Research, the systematic in-
quiry into such phenomena as allied tele-
pathy, apparitions, clairvoyance, premoni-
tions, mediumistic phenomena, h a u n t e d
houses, dowsing and all residual mental phe-
nomena. Traditionally these alleged phenom-
ena have been associated with the belief in a
spiritual world and generally made evidence
of its existence. The London Society for Psy-
chical Research was incorporated to investi-
gate such phenomena in iXXj and has pub-
lished volumes of Proceedings and a Journal
representing the results of its work. An Am-
erican Society was founded in 1885, but soon
afterward was dissolved by union as a
Branch of the English Society. This branch
was later dissolved and a new society in
1906, to be independent of the parent body,
was organized. It publishes a monthly Journal
and Proceedings similar to those of the Brit-
ish Society.

Psychoanalysis. See Psychotherapy.

Psychology. Psychology is sometimes de-
fined as the science of mind and sometimes
as the science of behavior. These two defini-
tions mark a fundamental divergence of opin-
ion. The older scientific psychology concerns
itself with the study of mind and defines
mind as the sum total of immediate experi-
ence. More recent psychological trends have
been toward behaviorism, which studies, not
the immediate experience of an animal or
human being, but its behavior or actions in
response to certain stimuli. The greater body
of scientific results has been obtained under
the former point of view. The behavioristic
attitude came much later and was first ap-
plied to the study of animals. Afterwards in
mental tests and in diagnosis of mental dis-
ease this attitude was extended to the study
of human beings. All scientific results require
previous observation by highly trained ob-
servers. In the older psychology a trained
observer observes and reports upon his own
mental processes. Jn a behavioristic psychol-
ogy a trained observer observes the behavior
of others, notably of very young children
who have not yet had opportunity to learn
ways of action. In general the two methods
yield disparate results and can not be com-
pared. For the former consult works by
Titchener and Boring; for the latter, works
by John B. Watson.

Of the numerous topics in the older psychol-
ogy memory is selected for discussion here.
Memory can be explained by the law of
association. This law may be stated: when-

3858________________Psychology

ever a sensation or image comes into mind,
there tend to come with it all the other sen-
sations and images that have ever before
been in mind with it. Naturally there are
too many previous associates for them all to
appear at any time; there must be some sel-
ection. The laws of memory state the prin-
ciples under which the selection occurs. A
thing can not lake on meaning for us as idea
or perception unless it is in some way fam-
iliar. The term memory is usually restricted
to a successive revival of sensations and im-
ages by association, e.g., the bringing up of
one idea out ot another or out of a percep-
tion, and thus does not include the almost
simullaneous association of the perceptual
context and core.

The laws of memory have been worked
out by experiments in the psychological lab-
oraton. A subject is required to learn some
material—prose, poetry, or a series of non-
sense syllables like hain-titp-lor-kiz-wex.
Learning is very greatly aided by a mental
grouping of the material into parts. Nonsense
syllables are most easily learned when re-
peated in rhythm, and poetry is easier to
learn than prose. Meaningful material is
much more easily mastered than nonsensv\
and the more meaningful the material the
easier it is to learn it. It is always easier to
learn understanding!}* than blindly.

It is best to go over material slowly if
permanent acquisition is desired. A doctor's
knowledge that must needs be always avail-
able should be acquired as slowly as is com-
patible with good attention, if the learning
is to be efficient. The speaker, however, who
prepares for a particular address should go
over his notes rapidly well in advance and
also just before the time of the speech. He
thus learns more economically for the given
occasion, but forgets faster afterwards than
he would have done with slow learning, Ec-
onomy of learning is also secured by a widv
temporal distribution of the repetitions for
learning. More is learned by two repetitions
of a given material on each of six clays than
by six repetitions on each of two days; and,
within practical limits, the longer the time
through which the effort is distributed the
greater the result.

In a long material economy is served by
repeating the whole material as a unit rathei
than by learning it one part at a time, Op-
posed to this rule is the fact that long ma-
terials are intrinsically difficult; doubling the
length of a task more than doubles the effort
required for its learning. The gain, however,