Key Concepts in Psychology: Chapters 1-3 Definitions

Hindsight Bias

Thinking you knew the outcome all along.

Overconfidence

Thinking you know more than you do.

Critical Thinking

Examining assumptions, evaluating evidence.

Theory

Explanation that organizes and predicts.

Hypothesis

Testable prediction.

Operational Definition

Definition of a variable in specific terms.

Replication

Repeating a study to test reliability.

Case Study

Studying one or more individuals in depth.

Survey

Asking questions to gather self-reported data.

Random Sample

Fair representation; everyone has an equal chance.

False Consensus Effect

Overestimating how much others agree.

Population

All cases in a group being studied.

Naturalistic Observation

Observing in natural settings.

Correlation Coefficient

Statistical measure of relationship strength.

Scatterplot

Graph showing the relationship between two variables.

Illusory Correlation

Thinking there's a relationship when none exists.

Experiment

Manipulating variables to observe effects.

Placebo

Fake treatment.

Double-Blind Procedure

Neither participants nor researchers know group assignment.

Experimental Condition

Group receiving treatment.

Control Condition

Group not receiving treatment.

Random Assignment

Randomly placing participants in conditions.

Independent Variable

Variable manipulated.

Dependent Variable

Variable measured.

Mode

Most frequent score.

Mean

Average.

Median

Middle score.

Range

Difference between high and low scores.

Standard Deviation

How much scores vary around the mean.

Statistical Significance

How likely a result is due to chance.

Culture

Shared ideas, traditions, passed to future generations.

Biological Psychology

Study of links between biology and behavior.

Neuron

Basic nerve cell.

Dendrite

Branches that receive messages.

Axon

Sends messages away.

Myelin Sheath

Fatty layer that speeds impulses.

Action Potential

Brief electrical charge down axon.

Threshold

Level needed to trigger impulse.

Synapse

Gap between neurons.

Neurotransmitters

Chemical messengers.

Acetylcholine (ACh)

Triggers muscle movement.

Endorphins

Natural painkillers, pleasure.

Agonist

Mimics neurotransmitter.

Antagonist

Blocks neurotransmitter.

Nervous System

Body's fast communication network.

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

Connects CNS to rest of body.

Sensory Neurons

Send info to CNS.

Interneurons

Connect sensory and motor neurons in CNS.

Motor Neurons

Carry info from CNS to muscles.

Somatic Nervous System

Controls voluntary movements.

Autonomic Nervous System

Controls glands and internal organs.

Sympathetic Nervous System

Arouses body, stress.

Parasympathetic Nervous System

Calms body.

Reflex

Automatic response.

Neural Networks

Neurons linked by experience.

Brainstem

Oldest part, survival functions.

Medulla

Controls heartbeat, breathing.

Reticular Formation

Controls arousal.

Thalamus

Sensory switchboard.

Cerebellum

Balance, movement.

Limbic System

Emotions, drives.

Amygdala

Emotion processing.

Hypothalamus

Hunger, thirst, body temp.

Cerebral Cortex

Information processing center.

Glial Cells

Support neurons.

Frontal Lobes

Planning, speech, movement.

Parietal Lobes

Sensory input.

Occipital Lobes

Vision.

Temporal Lobes

Hearing.

Motor Cortex

Voluntary movements.

Sensory Cortex

Processes touch, sensations.

Aphasia

Language impairment.

Broca's Area

Speech production.

Wernicke's Area

Language comprehension.

Plasticity

Brain's ability to change.

Corpus Callosum

Connects brain hemispheres.

Split Brain

Two hemispheres disconnected.

Endocrine System

Slow chemical messaging via hormones.

Hormones

Chemical messengers.

Adrenal Glands

Release adrenaline.

Pituitary Gland

Master gland, controls others.

Chromosomes

DNA structures that contain genes.

DNA

Genetic material in double-helix form.

Genes

Units of heredity, segments of DNA.

Genome

Complete genetic instructions.

Natural Selection

Traits that enhance survival are passed on.

Mutations

Random gene changes causing diversity.

Evolutionary Psychology

Study of how evolution shapes behavior.

Gender

Traits by which we define male/female.

Behavior Genetics

Study of genetic and environmental effects on behavior.

Environment

Non-genetic influences.

Identical Twins

One egg split into two.

Fraternal Twins

Two separate eggs.

Temperament

Emotional reactivity.

Heritability

Proportion of variation due to genes.

Interaction

Effect of one factor depending on another.

Molecular Genetics

Study of gene structure and function.

Culture

Shared ideas, traditions passed through generations.

Norm

Accepted behavior rule.