342 ❯ GlossaryPersonal fable—exaggerated belief in a person’s
unique ness and immortality in adolescence.
Personal unconscious—according to Jung, a store-
house of all our past memories and hidden instincts
and urges unique to the individual.
Personality—a unique pattern of consistent feelings,
thoughts, and behaviors that originate within the
individual.
Personality disorders—chronic, maladaptive thought
and behavior patterns that are troublesome to
others, harmful, or illegal.
Phallic stage—Freud’s third stage of psychosexual
development; the primary erogenous zone is the
genital area; during this time children become
attached to the opposite-sex parent.
Phenotype—the expression of the genes.
Phenylketonuria (PKU)—recessive trait that results
in severe, irreversible brain damage unless the baby
is fed a special diet low in phenylalanine.
Phobia—irrational fear of specific objects or situa-
tions, such as animals or enclosed spaces.
Phonemes—smallest possible sound units of spoken
language.
Photoreceptors—modified neurons (rods and cones)
that convert light energy to electrochemical neural
impulses at the retina.
Physiological motivations—such as hunger, thirst
and sex. Each is influenced by biological factors,
environmental factors and learned preferences and
habits. The hypothalamus and endocrine system
are implicated in each of these motives.
Pineal gland—endocrine gland in brain that produces
melatonin that helps regulate circadian rhythms
and is associated with seasonal affective disorder.
Pitch—the highness or lowness of a sound. The
shorter the wavelength, the higher the frequency
and pitch. The longer the wavelength, the lower
the frequency and the lower the pitch.
Pituitary gland (sometimes called master gland)—
endocrine gland in brain that produces stimulat-
ing hormones which promote secretion by other
glands, including TSH (thyroid-stimulating hor-
mone); ACTH (adrenocorticotropic hormone),
which stimulates the adrenal cortex; FSH (follicle
stimulating hormone), which stimulates egg or
sperm production; ADH (antidiuretic hormone),
to help retain water in your body; and HGH
(human growth hormone).
Place theory—the position on the basilar membrane
at which waves reach their peak depending on
the frequency of a tone. Accounts well for high-
pitched sounds.
Placebo—a physical or psychological treatment given
to the control group that resembles the treatmentgiven to the experimental group, but contains no
active ingredient.
Placebo effect—a response to the belief that the
independent variable will have an effect, rather
than to the actual effect of the independent vari-
able; can be a confounding variable.
Plasticity—modifiability of neural connections that
enables generation of new synapses which results in
storing and retrieval of memories or one part of the
brain taking over the function of another.
Pleasure principle—Freud’s claim that the id part of
the personality seeks immediate gratification of its
wants and needs.
Pons—part of brainstem that includes portion of retic-
ular activating system or reticular formation critical
for arousal and wakefulness; sends information to
and from medulla, cerebellum, and cerebral cortex.
Population—all of the individuals in the group to
which the study applies.
Positive psychology—the scientific study of optimal
human functioning.
Positive reinforcement—a rewarding consequence
that follows a voluntary behavior thereby increas-
ing the probability the behavior will be repeated.
Positron emission tomography (PET)—shows
brain activity when radioactively tagged glucose
rushes to active neurons and emits positrons.
Postconventional level—Kohlberg’s third and final
level of moral development, in which people come
to understand that moral rules include principles
that apply across all situations and societies.
Post-traumatic stress disorder (PTSD)—disorder
in which the individual has feelings of social
withdrawal accompanied by atypically low levels
of emotion caused by prolonged exposure to a
stressor, such as a catastrophe; may experience
flashbacks and nightmares.
Power tests—difficulty level measured; untimed tests
which include easy to more difficult questions,
used to assess intelligence and other capacities.
Preconscious—the level of consciousness that is
outside of awareness but contains feelings and
memories that can easily be brought to conscious
awareness.
Preconventional level—Kohlberg’s first level of
moral development, which bases moral behavior
on obedience and punishment, or acting in one’s
own best interests.
Predictive validity—the extent to which a test accu-
rately forecasts a specific future result.
Prefrontal lobotomy—a surgical procedure that
destroys the tracts connecting the frontal lobes to
lower centers of the brain, once believed to be an
effective treatment for schizophrenia.BM.indd 342 27-05-2018 15:32:47