Barron’s AP Psychology Comprehensive Vocabulary Review

A collection of essential vocabulary terms covering major units of AP Psychology, including research methods, biological bases, cognition, development, and social psychology.

Humanist Perspective

A psychological perspective that stresses individual choice and free will, believing that behaviors are guided by physiological, emotional, or spiritual needs.

Biopsychosocial Perspective

A modern perspective that acknowledges human thinking and behavior result from combinations of biological, psychological, and social factors.

Hindsight Bias

The tendency for people to believe, after an event has occurred, that they could have predicted the outcome or that they knew it all along.

Applied Research

Psychological research conducted to solve practical, real-world problems, such as comparing different methods of teaching children to read.

Operational Definitions

A clear, measurable explanation of how a researcher will define and measure a specific variable in a study.

Random Sampling

A selection process where every member of the population has an equal chance of being selected for the sample, allowing for generalization.

Confounding Variable

Any difference between the experimental and control conditions, except for the independent variable, that might affect the dependent variable.

Double-blind Study

An experimental procedure where neither the participants nor the researcher interacting with them know which group (experimental or control) the participants are in.

Hawthorne Effect

The finding that merely selecting a group of people to be part of an experiment can affect the performance of that group, regardless of the treatment.

Positively Skewed

A distribution that includes an extreme score (outlier) that is very high, causing the mean to be higher than the median.

Z-scores

A measure that indicates how many units of standard deviation a score is away from the mean; scores below the mean are negative, and scores above the mean are positive.

Normal Curve

A theoretical bell-shaped curve where approximately $68\%$ of scores fall within $1$ standard deviation, $95\%$ within $2$, and $99\%$ within $3$ standard deviations of the mean.

P-value

The probability that the difference between groups in a study is due to chance; researchers typically use a cutoff of $0.05$ for results to be considered statistically significant.

Informed Consent

An ethical guideline requiring that participants know they are involved in research and voluntarily agree to participate.

Resting Potential

The slightly negative charge of a neuron when it is not firing, typically measured at $-70\,mV$.

All-or-none Principle

The principle that a neuron either fires completely once it reaches its threshold or it does not fire at all; the impulse is the same every time.

Dopamine

A neurotransmitter associated with motor movement and alertness; a lack is linked to Parkinson's disease, while an overabundance is linked to schizophrenia.

Sympathetic Nervous System

The part of the autonomic nervous system that mobilizes the body's 'fight-or-flight' response to stress by accelerating heart rate and respiration.

Broca’s Area

A region in the frontal lobe, usually in the left hemisphere, responsible for controlling the muscles involved in producing speech.

Wernicke’s Area

A region in the temporal lobe involved with linguistic processing and the ability to understand written and spoken language.

Blood-brain Barrier

Thick walls surrounding the brain's blood vessels that protect the brain from harmful chemicals in the bloodstream.

Circadian Rhythm

A biological pattern of metabolic and thought processes that follows a 24-hour cycle, including the typical pattern of sleep.

Transduction

The transformation of sensory signals (like light or sound waves) into neural impulses that the brain can interpret.

Weber’s Law

A psychophysics principle stating that the amount of change needed to notice a difference in a stimulus is proportional to the original intensity of that stimulus.

Algorithm

A problem-solving rule that guarantees the correct solution by testing every possible option using a specific formula.

Functional Fixedness

The inability to see a new or unconventional use for an object, which acts as an impediment to problem-solving.

Chunking

A memory technique of grouping items into no more than seven meaningful units to expand the capacity of short-term memory.

Retroactive Interference

A phenomenon where the learning of new information interferes with the ability to recall older information.

Fluid Intelligence

The ability to solve abstract problems and pick up new information and skills, which tends to decrease as adults age.

Teratogens

Chemicals or agents, such as alcohol or drugs, that can pass through the placenta and cause harm to a developing fetus.

Object Permanence

A cognitive milestone in Piaget's sensorimotor stage where a child realizes that objects continue to exist even when out of sensory range.

Fundamental Attribution Error

The tendency for observers to overestimate the importance of dispositional factors and underestimate situational variables when explaining others' behavior.

Cognitive Dissonance Theory

The theory that people experience unpleasant mental tension when their attitudes and behaviors are inconsistent, motivating them to change their attitudes.

Big Five Personality Traits

The five broad dimensions used to describe personality: extraversion, agreeableness, conscientiousness, openness to experience, and emotional stability (neuroticism).

Yerkes-Dodson Law

The principle that performance increases with physiological or mental arousal, but only up to a certain point; too much arousal can decrease performance on difficult tasks.