Libido—life/sexual energy force of the id (according
to Freud).
Linguistic relativity hypothesis—Whorf ’s belief
that the language you speak guides and determines
your thinking; largely discredited.
Lithium carbonate—the drug treatment of choice
for bipolar disorder; it reduces levels of certain neu-
rotransmitters and decreases the strength of neural
firing.
Locus of control—the degree to which we expect
that a reinforcement or outcome of our behavior is
contingent on our own behavior or personal char-
acteristics (internal locus of control) as opposed to
the degree to which we expect that a reinforcement
or outcome of our behavior is a function of luck or
fate, is under the control of others, or is unpre-
dictable (external locus of control).
Long-term memory (LTM)—the relatively perma-
nent and unlimited capacity memory system into
which information from short-term memory may
pass.
Long-term potentiation (LTP)—an increase in a
synapse’s firing potential after brief, rapid stimula-
tion and possibly the neural basis for learning and
memory.
Longitudinal research—a method of assessing devel-
opmental changes by evaluating the same group of
people at different times in their lives.
Lucid dreaming—the ability to be aware of and
direct your dreams.
Magnetic resonance imaging (MRI)—detailed
computerized images using a magnetic field and
pulses of radio waves that cause emission of signals
that depend upon the density of tissue.
Maintenance rehearsal—repeating a given item over
and over again extends your short-term memory;
usually limited to about 20 seconds.
Major (clinical) depression—persistent and severe
feelings of sadness (dysphoria) and worthlessness
accompanied by changes in appetite, sleeping, and
behavior.
Maladaptive behavior—behavior which is counter-
productive; interferes with one’s interaction in soci-
ety, and is a factor in mental illness.
Mandala—According to Jung, a type of magical
circle symbolizing the self archetype in the collec-
tive unconscious.
Mania—excessive emotional arousal (euphoria) and
wild, exuberant, unrealistic activity.
Manifest content—according to Freud, the remem-
bered story line of a dream.
Maturation—the biological growth processes that
bring about orderly changes in behavior, thought,
or physical growth; relatively unaffected by
experience (nature argument).
Mean—the arithmetic average of a set of scores.
Median—the middle score when a set of data is
ordered by size.
Medulla oblongata—part of brainstem that regulates
heart rhythm, blood flow, breathing rate, diges-
tion, vomiting.
Memory—human capacity to register, retain, and
retrieve information over time; the persistence of
learning.
Menarche—first menstrual period at about age 12^1 / 2 ;
marks female fertility.
Menopause—the cessation of the ability to repro-
duce accompanied by a decrease in production of
female sex hormones at about age 50.
Mental age—a measure of your intellectual develop-
ment; the level of mental development relative to
others.
Mental retardation—intellectual deficiency charac-
terized by intelligence quotient at least two stan-
dard deviations below the mean and difficulty in
adapting to and coping with environmental
demands of independent living.
Mental set—tendency to apply problem-solving
methods that have worked in the past rather than
trying new or different strategies to solve a new
problem, which may or may not help solve the
problem.
Mere exposure effect—the formation of a positive
attitude toward a person, place, or thing based
solely on repeated exposure to that person, place,
or thing; often used in advertising as form of subtle
persuasion.
Mesomorph—one of three body types (domineering,
aggressive, muscular) developed in Sheldon’s per-
sonality theory that correlates personality traits and
physique.
Meta-analysis—systematic statistical method for
synthesizing the results of numerous research stud-
ies dealing with the same variables.
Metabolism—the sum total of all chemical processes
that occur in our bodies which are necessary to
keep us alive.
Metacognition—thinking about how we think.
Method of loci—a mnemonic device which uses
visualization of familiar objects on a familiar path
to recall information in a list.Glossary Ü 327