Developmental psychology.pdf

602 Glossary
telegraphic utterances Word combinations which convey
the essential elements of a message while omitting
nonessential elements; frequent among children in the
early stages of language acquisition.
telepathy An aspect of extrasensory perception in which
someone allegedly is able to know another person's
thoughts without any of the traditional sensory
modalities. See also clairvoyance and precognition.
temporal lobes Areas of the cerebrum below the lateral
fissure, adjacent to the temples. They contain auditory
areas and auditory association areas.
terminal plateau A flat place at the end of a learning curve
indicating no further improvement in performance. This
plateau presumably represents a physiological limit in
the organism; the individual simply cannot perform the
task any more rapidly or successfully.
terminal threshold See threshold.
test battery д group of tests designed to assess an
individual, usually with respect to intelligence,
personality, aptitude, interests, and/or achievement.
testes The male glands; the male organs of reproduction.
testing a hypothesis in research, gathering information for
one view or another; attempting to obtain information in
support of a particular viewpoint.
test-retest reliability The consistency of measurement
obtained when a test is administered on two different
occasions to the same subjects.
texture gradient in the visual perception of space, a cue
to distance based on the haziness of details due to
atmospheric interference. Objects at a distance appear
hazier and less distinct than nearby objects.
T-group See encounter group.
thalamus (thal'-uh-mus) A structure between the brain
stem and cerebrum which serves as a switchboard
mechanism to relay sensory impulses to the appropriate
regions of the cerebral cortex and which also mediates
sensitivity and modifiability at a primitive level.
Thematic Apperception Test (TAT) A projective test in
which the subject makes up stories appropriate to a
series of pictures; themes of his or her stories give an
indication of basic personality structure.
theory A set of principles with some explanatory value.
theory of evolution See evolution, theory of.
theory of psychoanalysis See psychoanalysis.
therapy A procedure designed to cure or alleviate some
disorder.
third-force psychology See humanistic psychology.
threshold The point at which an experience just barely
occurs. A stimulus of threshold strength is one which, if
it were weaker, would have no typical effect. A more
specific term is absolute threshold. A difference
threshold is one in which a difference is just barely
perceptible; the just noticeable difference or j.n.d. The
terminal threshold is the upper limit of sensitivity; the
point beyond which further increases in intensity have
no typical effect. "Typical effect" in these definitions
means no change in the type of experience being
studied. If increasing the intensity of light stimulation
brings pain, that is not a visual effect, hence not typical
for this kind of stimulation. Limen is a synonym for
threshold.
thyroid gland (thi'-royd) An endocrine gland situated near
the windpipe. Its secretion (thyroxin) is important for
metabolism. A marked deficiency of thyroxin in early life
may produce a form of mental deficiency known as
cretinism.
thyroxin (thl-rok'-sun) The secretion of the thyroid gland.
timbre Sound quality, as in the difference between the
same note played on a piano and on a cello. A function
of the complexity of sound waves, i.e., the overtones
produced.
time difference in auditory space perception, a cue to
distance based on the time when a sound reaches each
ear. A sound to the right of the listener will reach the
right ear slightly before it reaches the left ear. See
intensity difference, phase difference.
time expansion in drug usage, experiencing a scene or
event as lasting much longer than it would seem under
conditions of normal stimulation.
token economy A program of therapy based upon operant
conditioning in which secondary reinforcement is widely
used. The secondary reinforcers are tokens or chips,
awarded for certain behaviors, and they can be
exchanged later for some desirable event. The token
economy is most widely used in mental hospitals, where
the tokens are exchanged for permission to leave the
ward, attend movies and dances, and make purchases
on shopping trips.
totally dependent The most extreme condition of
retardation. Persons in this classification require
custodial care for personal needs and survival. See
retarded.
trace conditioning A method of classical conditioning in
which the conditioned stimulus is removed before the
appearance of the unconditioned stimulus.
trainable The middle classification of the mentally
retarded. Judged unable to profit from traditional
classroom education, even at a slower rate, the trainable
child instead is assisted in the development of self-help
skills, including personal care and hygiene and limited
tasks in the home. See retarded.
trait A relatively constant aspect, characteristic, or
dimension of behavior. Usually applied to personality
and exemplified by such terms as introversion,
dominance, sociability, persistence, and honesty.
trait approach The study of personality which focuses
upon personal disposition or traits; techniques of
personality assessment involving inventories and
questionnaires. See trait.
transactional analysis A method of group therapy
emphasizing interpersonal actions. Participants arrange
activities in pairs or small groups, while other members
analyze and interpret these events. The focus is upon
detecting undesirable elements in interpersonal
communication.