way we live our lives trying to make sense out of
what happens.
Personal 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 trouble-
some 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 pro-
duces 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 stimulating
hormones which promote secretion by other
glands, including TSH (thyroid-stimulating hor-
mone); ACTH (adrenocorticotropic hormone),
which stimulates the adrenal cortex; FSH, which
stimulates egg or sperm production; ADH (antidi-
uretic 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 treatment
given 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
reticular activating system or reticular formation
critical for arousal and wakefulness; sends informa-
tion 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
increasing 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)—an anxiety
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 out-
side of awareness but contains feelings and memo-Glossary Ü 331