Psychology Dictionary -- S


Portion of the entire population used to estimate what is likely happening within a population.

Sample Mean

Abbreviated with a lowercase x with a horizontal line over top (called ‘x-bar’), the sample mean is the true mean of a sample of data often used to estimate the true mean of the entire population.

Sample Standard Deviation

The standard deviation of a sample of the population. Often used to estimate the true population standard deviation. Often abbreviated ‘SD.”

Sampling Error

The amount of error associated with a sample due to its deviation from the population

Scatter Plot

A graphical representation of data received in a correlational study.


The cognitive structure utilized to make sense of the world.

Secondary Reinforcer

A reinforcer other than one which meets our basic needs such as food or water (e.g., intellectual stimulation, money, praise).

Selection Bias

Errors in the selection and placement of subjects into groups that results in differences between groups which could effect the results of an experiment.

Self Actualization

The process of understanding oneself more completely and being aware of issues affecting one’s life.


The subjective perception of the self.

Self Efficacy

One’s belief in his or her own ability.

Self Serving Bias

The tendency to assign internal attributes to successes and external factors to failures.

Semantic Memory

The part of declarative memory that stores general information such as names and facts.

Semi-Interquartile Range

One half of the interquartile range


Information brought in through the senses.

Sensorimotor Stage

The first stage in Piaget’s Stages of Cognitive Development where a child’s primary way of learning about the world is through the senses and movement.

Sensory Adaptation

The reduced ability to sense a stimulus after prolonged exposure.

Sensory Memory

The brief storage of information brought in through the senses; typically only lasts up to a few seconds.

Separation Anxiety

Distress caused by the absence of an infant’s primary caregiver


A neurotransmitter involved in mood, sleep, appetite, and impulsive and aggressive behavior. Too little has been associated with depression and some anxiety disorders (e.g., obsessive-compulsive disorder). Many antidepressants attempt to reduce the amount of serotonin that is taken back (reuptake) into the sending neuron (e.g., Serotonin Reuptake Inhibitors [SRI]).

Sexual Orientation

A feeling of attractedness or arousal associated with a particular gender. Sexual behavior can be a result of this but does not necessarily define a person’s orientation.


Gradually molding a specific response by reinforcing responses that come close to the desired response.

Short Term Memory

The stage of memory where information is stored for up to 30 seconds prior to either being forgotten or transferred to long term memory.

Sigma (lowercase)

The abbreviation for the standard deviation of a population. (s)

Sigma (uppercase)

The abbreviation for summation. (S)

Situational Attribute

An attribute explained or interpreted as being caused by external influences.

Skinner, B. F.

Considered the father of behavioral therapy. He once stated that with the ability to control a child’s environment, he could raise a child to become anything he wanted.

Skinner Box

A cage designed for animals in operant conditioning experiments.


The degree to which a curve or distribution of scores has extreme scores atypical of the majority of scores

Social Facilitation

The effect of other’s presence on one’s performance. Typically we perform simple or well-learned tasks better in front of others and difficult or novel tasks worse.

Social Learning Theory

Developmental theory arguing that personality is learned through the interactions with the environment.

Social Loafing

The tendency for people to work less on a task the greater the number of people are working on that task.

Social Psychology

The branch of psychology which focuses on society and it’s impact on the individual.

Social Roles

Accepted behaviors associated with a particular position within a group.

Social Skills

Skills or behaviors deemed desirable or necessary to effectively interact with society.

Social Support

Term used to describe the degree of emotional support afforded a client by friends, family, and other acquaintances.

Somatic Nervous System

Sub system of the Peripheral Nervous System (PNS). Primary function is to regulate the actions of the skeletal muscles.

Spearman’s Rho

A correlational technique used primarily for rank ordered data (ordinal scale).

Split-Half Reliability

The correlation coefficient determined by comparing first half of the measurement to the second half. Measure of the internal consistency of a test or measuring device.

Spontaneous Recovery

The tendency for previously learned information to resurface rapidly after a period of extinction. Information that is spontaneously recovered is thought to lay dormant but not forgotten (e.g., riding a bicycle after a long period of not riding).


A period of development that occurs at about the same time for each person. Developmental and Personality theories are often made up of a series of stages.

Stage Theory

The idea that an individual must pass through one stage of development before he or she can reach the next stage.

Standard Deviation

A measure of spread within a distribution (the square root of the variance). The most popular and most reliable measure of variability but the more skewed a distribution, the more error there will be in the standard deviation because of its reliance on the mean.

Standard Error of Measurement

a statistical procedure used to determine the amount of error of any measurement device

Standard Error of the Mean

An estimation of the unaccounted for error within a mean. If the mean is 10 and the standard error of the mean is 2, then the true score is likely to fall somewhere between 8 and 12 or 10 +/- 2.


The process of making a test or procedure the same for everyone so that results can be compared to each other.

Standard Score

A score derived by transforming the data based on the standard deviation. Standard scores can then be compared to one another on face value. (See z-score, T-score, NCE score, stanines, and Wechsler’s Deviation IQ Score)


A standard score that literally means Standard Nine, stanines have a mean of five and a standard deviation of approximately two. Stanines 2 through 8 are exactly 1/2 standard deviations and stanines one and nine or open ended.


An observed characteristic of a sample (e.g., 20% improvement rate, range of IQ’s)


A temporary internal characteristic (e.g., depressed, angry)

State Dependent Memory

The theory that information learned in a particular state of mind (e.g., depressed, happy, somber) is more easily recalled when in that same state of mind.

Stem and Leaf Display

A multiple column table depicting the individual digits of the scores. A score of 95 would have a stem of 9 and a leaf of 5, a score of 62 would have a stem of 6 and a leaf of 2. If a particular stem has more than one leaf, such as the scores 54, 58, and 51, the stem of 5 has three leaves, in this case 458.


Anything in the environment to which one responds.

Stimulus Discrimination

The ability to tell the difference and therefore not respond to similar stimuli.

Stimulus Generalization

The response to new stimuli due its similarity to the original stimuli.


The process of saving information in long term memory


The physical and psychological result of internal or external pressure.


Anything, internal or external, which applies psychological pressure on an individual.


School of thought from the 19th century focused on the gathering of psychological information through the examination of the structure of the mind.

Subjective Reality

The perception of reality made by an individual that may be different from the perception made by another person.

Subject Matching

A method of reducing bias in a sample of subjects by matching specific criteria of the sample to the true characteristics of the population. (Example: If the population is 60% female then 60% of the subjects in the sample should also be female)


A defense mechanism where undesired or unacceptable impulses are transformed into behaviors which are accepted by society.


In Psychoanalytical theory, the part of the personality that represents the conscience.


Hans Eysenck’s term for his two distinct categories of personality traits. They include Introversion-Extroversion and Neuroticism. According to Eysenck, each of us fall on a continuum based on the degree of each supertraits.


The defense mechanism where we push unacceptable thoughts out of consciousness and into our unconscious.


A research technique in which subjects respond to a series of questions.


Aristotle’s theory of reasoning where two true statements are followed by a single logical conclusion.

Sympathetic Nervous System (SNS)

Part of the Autonomic Nervous System responsible for the fight or flight phenomenon and which plays a role (along with the Parasympathetic Nervous System) in maintaining the body’s homeostasis.


The space between the axon of one neuron and the dendrites of another through which neurotransmitters travel.

Systematic Desensitization

A treatment technique where the client is exposed to gradually increasing anxiety provoking stimuli while relaxing; the goal is for the client to eventually confront a phobia or fear without the previously associated anxiety.