Psychology Glossary: A Index

An ABA design is a type of experimental design in which participants are first introduced to a baseline condition (A)...

A segment of psychology that deals with psychopathology and abnormal behavior...

The smallest detectable level of a stimulus...

Initially proposed by Piaget, the term refers to part of the adaptation process...

Acetylcholine (often abbreviated ACh) is the most common neurotransmitter and can be found in both the central nervous system (CNS) and the peripheral nervous system (PNS)...

The first stages of learning during which a response is established...

An action potential is an important part of the neural firing process. Learn more about what an action potential is and how it contributes to transmitting neural messages...

The activation-synthesis model is a theory of dreaming developed by researchers J. Allan Hobson and Robert McCarley...

In social psychology, we tend to attribute our own actions to external factors and other people's actions to internal ones. Why do we do this? Learn more about the psychology behind the actor-observer bias.

The acute stress response is commonly referred to as the flight-or-flight response. It describes how the body reacts when confronted with a stressful situation.

A term referring to the ability to adjust to new information and experiences...

Addiction is marked by drug-seeking behaviors in addition to the abuse of psychoactive substances...

Attention Deficit Hyperactivity Disorder (ADHD) is a behavioral and developmental disorder that usually becomes apparent during the preschool and early school years...

Adrenal glands are a type of endocrine gland that are triangle-shaped and located on top of the kidneys...

The symptoms of adult ADHD are the same as those experienced by children with ADHD, but it is usually more difficult to recognize the symptoms of impulsivity, distractibility and restlessness in adults...

Ageism is a form of prejudice characterized by discrimination against people based on their age. Much like other forms of prejudice, agism involves holding negative beliefs about people of certain ages...

In psychology, aggression involves numerous types of actions that can hurt or harm oneself or other people...

Agoraphobia is an anxiety disorder marked by fear and avoidance of public places. Find out more about symptoms and treatments for this agoraphobia.

Algorithms are often used in mathematics and problem solving. Learn more about what an algorithm is and how it compares to other problem-solving strategies.

The all-or-none law is a principle that applies to the firing of neurons. Learn more about what the all-or-none law is and how it relates to neural firing.

The amygdala is a small structure found in the limbic system and association with emotions, aggression and memory...

The anal stage is the second stage of Freud’s stages of psychosexual development, lasting from age 18 months to three years...

An eating disorder characterized by a distorted body image and self-starvation despite extremely low body-weight...

A personality characterized by symptoms such as fire-setting, cruelty to animals, lack of remorse and a lack of empathy...

Applied research refers to scientific study and research that seeks to solve practical problems...

Swiss psychiatrist Carl Jung believed that archetypes are models of people, behaviors or personalities. Jung suggested that the psyche was composed of three components: the ego, the personal unconscious and the collective unconscious..

Assimilation refers part of Jean Piaget's adaptation process in which people take in new information...

Attachment involves an enduring emotional bond between people...

Attention is a concept studied in cognitive psychology which refers to how we actively process specific information present in our environment...

Authoritative parenting is a parenting style characterized by strict rules, harsh punishments and little warmth. Learn more about the authoritarian parenting style and the effect it has on children...

Authoritative parenting is characterized by parents who hold high expectations and set clear guidelines, but are responsive and nurturing to their children...

Autocratic leadership, also known as authoritarian leadership, is a leadership style characterized by individual control over all decisions and little input from group members...

The autonomic system is the part of the peripheral nervous system that is regulates involuntary body functions including digestion and heartbeat.

Aversion therapy is a form of treatment that utilizes behavioral principles to eliminate unwanted behavior. Learn more about the uses, effectiveness and criticisms of aversion therapy.

Avoidant personality disorder is characterized by a chronic and pervasive pattern of distorted thought, emotion, behavior, and functioning...

The axon is an essential part of the neuron and is vital for the transmission of nerve impulses. Learn more about what an axon is and how it works...

Altruism is the opposite of selfishness, and involves doing for others without any expectation of reward...

An availability heuristic is a type of mental shortcut that involves basing judgements on information and examples that immediately spring to mind.