stimuli and experience drifting thoughts and
images. EEGs of stage 1 sleep show theta waves
which are lower in amplitude and frequency than
alpha waves.
Stage 2 sleep—sleep stage whose EEGs show high
frequency bursts of brain activity called sleep spin-
dles, and K complexes.
Stage 3 sleep—deep sleep stage whose EEGs show
some very high amplitude and very low frequency
delta waves.
Stage 4 sleep—deepest sleep stage whose EEGs show
mostly very high amplitude and very low fre-
quency delta waves. Heart rate, respiration, tem-
perature, and blood flow to the brain are reduced.
Growth hormone involved in maintaining physio-
logical functions is secreted.
Standard deviation(SD)—a measure of the average
difference between each score and the mean of the
data set; the square root of the variance.
Standardization—two-part test development proce-
dure that first establishes test norms by giving the
test to a large representative sample of those for
whom the test is designed, and then ensures that
the test is both administered and scored uniformly
for all test takers.
Standardized tests—set of tasks administered
under standard conditions to assess an individual’s
knowledge, skill, or personality characteristics.
Stanford-Binet intelligence test—Terman’s revision
of Binet’s original individual IQ test.
State-dependent memory—tendency to recall infor-
mation better if you are in the same internal state
as when the information was encoded.
Statistical significance (p)—condition that exists
when the probability that the observed findings are
due to chance is less than 1 in 20 (p<.05) accord-
ing to some psychologists or less than 1 in 100 (p
<.01) according to those with more stringent
standards.
Statistics—field that involves the analysis of
numerical data about representative samples of
populations.
Stereotype—overgeneralized belief about the charac-
teristics of members of a particular group; schema
used to quickly judge others.
Stereotype threat—anxiety that influences members
of a group concerned that their performance will
confirm a negative stereotype.
Stimulants—psychoactive drugs that activate moti-
vational centers and reduce activity in inhibitory
centers of the central nervous system by increasing
activity of serotonin, dopamine, and norepineph-
rine neurotransmitter systems; include caffeine,
nicotine, amphetamines, and cocaine.
Stimulus—a change in the environment that can be
detected by sensory receptors; elicits (brings about)
a response.
Storage—the retention of encoded information over
time.
Stranger anxiety—the fear of strangers that infants
develop at around 8 months of age.
Stress—the process by which we appraise and
respond to environmental threats.
Stressors—stimuli such as heat, cold, pain, that are
perceived as endangering our well-being.
Strive for superiority—according to Adler, this ten-
dency is a result of a need to compensate for our
feelings of inferiority.
Structuralism—early psychological perspective that
emphasized units of consciousness and identifica-
tion of elements of thought using introspection.
Sublimation—Freudian defense mechanism, expres-
sion of sexual or aggressive impulses redirected into
more socially acceptable behaviors.
Subliminal stimulation—receiving messages below
your absolute threshold for conscious awareness.
Sucking—the automatic response of drawing in any-
thing at the mouth.
Sulci—folding-in portions of convolutions of the
cerebral cortex.
Superego—the third part of Freud’s personality sys-
tems which makes us feel proud when we obey its
strict morality and feel guilt when we give in to the
id’s more pleasure-seeking urges.
Superstitious behavior—idiosyncratic, unimportant
behavior associated with anticipation of a reward as
a result of unintended reinforcement.
Surface trait—Cattell’s cluster of personality traits
which stems from deep source traits; the person we
see on the outside.
Survey—research method that obtains large samples
of abilities, beliefs, or behaviors at a specific time
and place through questionnaire or interview.
Swallowing—automatic contraction of throat mus-
cles that enables food to pass into the esophagus
without our choking.
Sympathetic nervous system—subdivision of PNS
and ANS whose stimulation results in responses
that help the body deal with stressful events.
Symptom substitution—the replacement of one
behavior that has been eliminated with another.Glossary Ü 337