Chapters 1-4

Empiricism

The idea that knowledge comes from experience, and that science should rely on observation and experimentation.

Structuralism

An early school of psychology that used introspection to explore the structure of the human mind; associated with Edward Titchener.

Functionalism

An early school of psychology focused on how mental and behavioral processes function—how they enable organisms to adapt, survive, and flourish; linked to William James.

Experimental Psychology

The study of behavior and thinking using the experimental method.

Behaviorism

The view that psychology should be an objective science that studies behavior without reference to mental processes.

Humanistic Psychology

A perspective that emphasized human growth potential and the importance of having our needs for love and acceptance satisfied.

Cognitive Neuroscience

The interdisciplinary study of brain activity linked with cognition, including perception, thinking, memory, and language.

Psychology

The scientific study of behavior and mental processes.

Nature–Nurture Issue

The debate over the relative contributions of biology (nature) and experience (nurture) to the development of psychological traits and behaviors.

Natural Selection

The principle that traits contributing to reproduction and survival are most likely to be passed on to future generations.

Levels of Analysis

The different complementary views—from biological to psychological to social-cultural—for analyzing any phenomenon.

Biopsychosocial Approach

An integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.

Behavioral Psychology

The scientific study of observable behavior and its explanation by principles of learning.

Biological Psychology

The scientific study of the links between biological (genetic, neural, hormonal) and psychological processes.

Cognitive Psychology

The scientific study of mental activities such as thinking, knowing, remembering, and communicating.

Evolutionary Psychology

The study of the evolution of behavior and mind using principles of natural selection.

Psychodynamic Psychology

The study of how unconscious drives and conflicts influence behavior, used in treating psychological disorders.

Social-Cultural Psychology

The study of how situations and cultures affect behavior and thinking.

Psychometrics

The scientific study of the measurement of human abilities, attitudes, and traits.

Basic Research

Pure science that aims to increase the scientific knowledge base.

Developmental Psychology

The study of physical, cognitive, and social change throughout the life span.

Educational Psychology

The study of how psychological processes affect and can enhance teaching and learning.

Personality Psychology

The study of an individual’s characteristic pattern of thinking, feeling, and acting.

Social Psychology

The scientific study of how we think about, influence, and relate to one another.

Applied Research

Scientific study that aims to solve practical problems.

Industrial-Organizational (I/O) Psychology

The application of psychological concepts to optimizing human behavior in workplaces.

Human Factors Psychology

A subfield of I/O psychology that explores how people and machines interact and how to make environments safe and user-friendly.

Counseling Psychology

A branch of psychology that assists people with life problems and helps them achieve well-being.

Clinical Psychology

A branch of psychology that studies, assesses, and treats people with psychological disorders.

Psychiatry

A branch of medicine dealing with psychological disorders; practiced by physicians who can prescribe medication and offer therapy.

Positive Psychology

The scientific study of human flourishing, with the goal of promoting strengths and virtues that help individuals and communities thrive.

Community Psychology

The study of how people interact with their environments and how social institutions affect individuals and groups.

Testing Effect

Improved memory after retrieving information, rather than simply rereading it.

SQ3R

A study method involving five steps: Survey, Question, Read, Retrieve, Review.

Hindsight Bias

The tendency to believe, after learning an outcome, that one would have foreseen it.

Critical Thinking

Thinking that does not blindly accept arguments and conclusions; it examines assumptions, evaluates evidence, and assesses conclusions.

Theory

An explanation using an integrated set of principles that organizes observations and predicts behaviors or events.

Hypothesis

A testable prediction, often implied by a theory.

Operational Definition

A carefully worded statement of the exact procedures used in a research study.

Replication

Repeating the essence of a research study, usually with different participants in different situations, to see if the findings extend to other circumstances.

Case Study

A descriptive technique in which one individual or group is studied in depth to reveal universal principles.

Naturalistic Observation

Observing and recording behavior in naturally occurring situations without trying to manipulate or control the situation.

Survey

A technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative sample.

Sampling Bias

A flawed sampling process that produces an unrepresentative sample.

Population

All those in a group being studied, from which samples may be drawn.

Random Sample

A sample that fairly represents a population because each member has an equal chance of inclusion.

Correlation

A measure of the extent to which two factors vary together and how well one predicts the other.

Correlation Coefficient

A statistical index of the relationship between two things (from −1.0 to +1.0).

Scatterplot

A graphed cluster of dots that represents the values of two variables; the slope suggests the direction of the relationship.

Illusory Correlation

The perception of a relationship where none exists.

Experiment

A research method in which an investigator manipulates one or more factors to observe the effect on a dependent variable.

Experimental Group

The group exposed to the treatment in an experiment.

Control Group

The group not exposed to the treatment; serves as a comparison for evaluating the effect of the treatment.

Random Assignment

Assigning participants to experimental and control groups by chance, minimizing preexisting differences.

Double-Blind Procedure

An experimental procedure in which both participants and research staff are ignorant about whether participants received the treatment or a placebo.

Placebo Effect

Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition.

Independent Variable

The factor that is manipulated; the variable whose effect is being studied.

Confounding Variable

A factor other than the independent variable that might produce an effect in an experiment.

Dependent Variable

The outcome that is measured; the variable that may change when the independent variable is manipulated.

Validity

The extent to which a test or experiment measures or predicts what it is supposed to.

Descriptive Statistics

Numerical data used to measure and describe characteristics of groups, including measures of central tendency and variation.

Mode

The most frequently occurring score in a distribution.

Mean

The arithmetic average of a distribution, obtained by adding the scores and dividing by the number of scores.

Median

The middle score in a distribution; half the scores are above it and half are below.

Skewed Distribution

A representation of scores that lack symmetry around their average value.

Range

The difference between the highest and lowest scores in a distribution.

Standard Deviation

A computed measure of how much scores vary around the mean score.

Normal Curve

A symmetrical, bell-shaped curve that describes the distribution of many types of data.

Inferential Statistics

Numerical data that allow one to generalize—to infer from sample data the probability of something being true of a population.

Statistical Significance

A statistical statement of how likely it is that an obtained result occurred by chance.

Culture

The enduring behaviors, ideas, attitudes, values, and traditions shared by a group of people and transmitted from one generation to the next.

Informed Consent

Giving potential participants enough information about a study to enable them to choose whether they wish to participate.

Debriefing

The post-experimental explanation of a study, including its purpose and any deceptions, to its participants.

Neuron

A nerve cell; the basic building block of the nervous system.

Dendrites

Branching extensions of a neuron that receive messages and conduct impulses toward the cell body.

Axon

The neuron extension that passes messages through its branches to other neurons or to muscles or glands.

Myelin Sheath

A fatty tissue layer segmentally encasing the axons of some neurons; enables faster transmission of impulses.

Action Potential

A neural impulse; a brief electrical charge that travels down an axon.

Refractory Period

A period of inactivity after a neuron has fired.

Threshold

The level of stimulation required to trigger a neural impulse.

All-or-None Response

A neuron's reaction of either firing (with a full-strength response) or not firing at all.

Synapse

The junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.

Neurotransmitters

Chemical messengers that cross the synaptic gaps between neurons.

Reuptake

A neurotransmitter's reabsorption by the sending neuron.

Endorphins

Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Agonist

A molecule that increases a neurotransmitter's action.

Antagonist

A molecule that inhibits or blocks a neurotransmitter's action.

Nervous System

The body’s speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems.

Central Nervous System (CNS)

The brain and spinal cord.

Peripheral Nervous System (PNS)

The sensory and motor neurons that connect the CNS to the rest of the body.

Nerves

Bundled axons that form neural 'cables' connecting the CNS with muscles, glands, and sense organs.

Sensory (Afferent) Neurons

Neurons that carry incoming information from the sensory receptors to the CNS.

Motor (Efferent) Neurons

Neurons that carry outgoing information from the CNS to the muscles and glands.

Interneurons

Neurons within the CNS that communicate internally and intervene between sensory inputs and motor outputs.

Somatic Nervous System

The part of the PNS that controls the body’s skeletal muscles.

Autonomic Nervous System (ANS)

The part of the PNS that controls the glands and the muscles of the internal organs.

Sympathetic Nervous System

Arouses the body, mobilizing its energy in stressful situations.

Parasympathetic Nervous System

Calms the body, conserving its energy.

Reflex

A simple, automatic response to a sensory stimulus.

Endocrine System

The body’s 'slow' chemical communication system; a set of glands that secrete hormones into the bloodstream.