AP PSYCH 2026 ALL TERMS

Heredity (Nature)

Genetic or predisposed characteristics that influence physical, behavioral, and mental traits and processes; characteristics we are born with.

Environmental Factors (Nurture)

External factors that influence us, such as family interactions or education.

Interactionist Perspective

The middle ground that merges the nature versus nurture debate, arguing that genetics and environment both influence human behavior.

Evolutionary Perspective

Explores how natural selection affects human behaviors and mental processes.

Natural Selection

Traits that ensure survival and reproductive success become dominant traits in humans.

Eugenics (Debunked Theory)

The idea that people can improve the human race by encouraging those with desirable traits to have children and preventing those with undesirable traits from reproducing; rejected due to ethical and scientific reasons.

Twin Studies

Compare identical twins (nearly 100% shared genes) and fraternal twins (average 50% shared genes) to assess the influence of genetics.

Family Studies

Look at how traits run in families by comparing parents, siblings, and extended relatives.

Adoption Studies

Compare adopted children to both their biological (genes) and adoptive (environment) families to determine the stronger effect.

Nervous System

The body's communication network for transmitting signals and coordinating actions.

Central Nervous System (CNS)

Includes the brain and spinal cord.

Brain

The command center controlling thoughts, emotions, movement, and vital functions.

Spinal Cord

A highway relaying messages between the brain and the rest of the body; plays a key role in reflexes.

Peripheral Nervous System (PNS)

Extends beyond the brain and spinal cord, carrying messages between the CNS and the rest of the body.

Autonomic Nervous System

Controls involuntary bodily functions.

Sympathetic Nervous System

Prepares the body for action in stressful situations (fight-or-flight response).

Parasympathetic Nervous System

Calms the body after stress has passed (rest and digest system).

Somatic Nervous System

Controls voluntary movements.

Neurons

Responsible for carrying electrical and chemical signals.

Glial Cells

Provide support by maintaining structure, insulating neurons, facilitating communication, and removing waste.

Reflex Arc

Rapid, automatic responses to stimuli that do not require input from the brain.

Neurotransmitters

Chemicals released into the synapse (the tiny gap between neurons).

Dopamine

Movement, motivation, and the brain's reward system.

Serotonin

Mood, appetite, and sleep.

Acetylcholine

Involved in muscle movement, attention, and memory.

Brain Stem

The oldest and most primitive part of the brain.

Cerebellum

Coordinates movement, maintains balance, and supports procedural learning.

Cerebral Cortex

The largest and most complex part of the brain; divided into two hemispheres.

Corpus Callosum

The connection between the brain's two hemispheres.

Brain Plasticity

The brain's ability to adapt and reorganize itself by forming new connections and compensating for damage.

Electroencephalograms (EEGs)

Measure electrical activity in the brain.

Functional Magnetic Resonance Imaging (fMRI)

Tracks blood flow to different brain regions, showing which areas are active during tasks.

Consciousness

Includes the two primary states of sleep and wakefulness.

Circadian Rhythm

A biological process (internal clock) that follows a roughly 24-hour cycle, regulated by environmental cues (e.g., light, temperature).

Jet Lag

Occurs when traveling across multiple time zones, misaligning the internal clock.

Shift Work

Requires being awake at night and sleeping during the day, interfering with natural sleep patterns.

NREM Sleep (Non-Rapid Eye Movement)

Consists of three progressively deeper stages.

Stage One

The lightest stage of sleep.

Hypnagogic Sensations

Brief sensory experiences (e.g., the feeling of falling).

Stage Two

A transitional stage preparing the body for deep sleep.

Stage Three

The deepest stage of sleep, crucial for physical restoration and immune function.

REM Sleep (Rapid Eye Movement)

Becomes more frequent as the night progresses; where most dreaming occurs.

Paradoxical Sleep

Called this because brain activity resembles wakefulness, but the body remains relaxed due to temporary muscle paralysis.

REM Rebound

Entering REM sleep more quickly and spending more time in this stage after being deprived of REM sleep.

Activation-Synthesis Theory

Dreams result from random neural activity in the brain stem that the brain then interprets as meaningful experiences.

Consolidation Theory

Dreams help process and store memories, strengthening learning and problem-solving skills.

Functions of Sleep

Memory consolidation, restoration of energy, and replenishment of biochemical resources.

Insomnia

Characterized by difficulty falling or staying asleep.

Narcolepsy

A neurological disorder causing sudden and uncontrollable sleep episodes during the day.

REM Sleep Behavior Disorder (RBD)

Body does not experience normal REM sleep paralysis, allowing individuals to physically act out their dreams.

Sleep Apnea

Repeated interruptions in breathing during sleep.

Somnambulism (Sleepwalking)

Engaging in complex behaviors while still asleep, typically during deep NREM sleep.

Sensation

The process of detecting information from the environment and converting it into neural signals for processing in the brain.

Absolute Threshold

The minimum intensity at which a stimulus can be detected at least half the time.

Just Noticeable Difference (JND)

The smallest detectable change in stimulus intensity.

Weber's Law

The ability to detect differences depends on the proportion of change rather than a fixed amount.

Sensory Adaptation

Occurs when the body becomes less sensitive to unchanging stimuli over time.

Sensory Interaction

The way different senses work together to enhance perception.

Synesthesia

A condition in which stimulation of one sense leads to experiences in another.

Retina

Contains specialized cells that detect light and convert it into neural signals.

Lens

Achieves focus through accommodation (adjusting focus for near or far objects).

Rods

Photoreceptor cells in the periphery of the retina that detect shapes and movement; highly sensitive to dim light.

Cones

Photoreceptor cells concentrated in the fovea that process color and fine detail.

Blind Spot

Area where the optic nerve exits the eye (the brain fills in missing details).

Attention

The mental process that allows us to focus on certain information while filtering out everything else.

Internal Factors

Our interests, emotions, and level of alertness influence what we pay attention to.

External Factors

Sudden changes in the environment that grab our attention.

Cocktail Party Effect

The ability to immediately pick up your name (or other important information) in a crowded, noisy room.

Inattentional Blindness

Failing to notice an unexpected object in the field of vision because attention is focused elsewhere.

Change Blindness

Failing to notice a change in a visual scene, even when the change is large.

Binocular Depth Cues

Require both eyes.

Retinal Disparity

The slight difference in the images perceived by each eye, which the brain uses to determine depth.

Convergence

The inward movement of the eyes when focusing on a nearby object.

Monocular Depth Cues

Require only one eye.

Relative Clarity

Clearer and sharper objects appear closer, while hazy or blurred objects appear farther away.

Relative Size

When two objects are known to be similar in size, the smaller one appears farther away.

Texture Gradient

The gradual decrease in detail and texture as an object's surface recedes into the distance.

Linear Perspective

The appearance of parallel lines converging as they extend into the distance.

Interposition

The perception that an object blocking part of another object is closer than the one it partially obscures.

Visual Perceptual Constancy

The brain's ability to perceive objects as stable and unchanging despite variations in sensory input.

Apparent Movement

Occurs when stationary objects are perceived as moving due to visual cues.

Concepts

Mental categories that help us group similar things together.

Prototype

The best or most typical example of a category.

Schemas

More complex mental frameworks that include not just a category, but also expectations, knowledge, and associations about that category.

Assimilation (Piaget)

Taking in new information but not changing the existing schema.

Accommodation (Piaget)

When new information forces a change in the schema itself.

Problem Solving

The process of finding solutions to difficult or complex issues.

Algorithm

A step-by-step procedure that guarantees the right answer if followed correctly.

Heuristics

A mental shortcut or rule of thumb that simplifies problem-solving.

Representativeness Heuristic

Judging something based on how well it matches expectations or stereotypes.

Availability Heuristic

Making decisions based on the first or most vivid example that comes to mind.

Mental Set

Relying on strategies that worked in the past, even if they are not the best solution in a new situation.

Priming

Exposure to certain stimuli influences decision-making.

Framing

How a decision is presented; people make different choices based on framing.

Gambler's Fallacy

Believing that past events affect future probabilities in situations where the outcomes are actually random.

Sunk Cost Fallacy

Continuing to invest time, money, or effort into something because one has already invested so much.

Executive Functions

Mental skills that allow people to set goals, make plans, stay organized, and control impulses.

Creativity

The ability to generate new ideas or concepts.

Divergent Thinking

Exploring many unique possible solutions to a single problem.

Convergent Thinking

Focusing on finding a single correct solution.