Neurodiversity: understanding natural variation in human brains Neurodiversity Overview of neurodiversity: concept, common conditions, history of the term, social and practical implications, and approaches to inclusion and accommodation.
Neuropsychology: the study of brain, behavior and cognition Neuropsychology Neuropsychology examines how brain structure and function relate to cognition and behaviour. It combines clinical assessment, experimental methods, and rehabilitation to study inju…
Neurosis: concept, history, symptoms, and modern classification Neurosis Neurosis is an historical psychiatric term for non-psychotic emotional disorders marked by distress and functional impairment. Modern systems reclassify many neuroses as anxiety an…
Night Terror (Sleep Terror): Symptoms, Causes, and Management Night terror A night terror is a sudden episode of intense fear during non-REM sleep, most commonly in children. This article covers signs, likely causes, diagnosis, safety measures and treatme…
Nightmare disorder: causes, symptoms, diagnosis, and treatment Nightmare disorder Nightmare disorder is a parasomnia marked by recurrent, disturbing dreams that cause distress or impairment. This article outlines features, causes, diagnosis, and common managemen…
Observer effect: measurement disturbance and observer bias Observer effect The observer effect describes how measurement or observation can change the phenomenon being measured, in physical experiments, social research and everyday perception.
Obsessive–compulsive personality disorder Obsessive-compulsive personality disorder A personality disorder marked by rigid perfectionism, strict adherence to rules, and interpersonal inflexibility that can impair work and relationships. Distinct from obsessive–com…
Oneirology: the scientific study of dreams Oneirology Oneirology is the scientific investigation of dreams: their neural basis, content, functions, measurement, and clinical relevance, distinct from symbolic interpretation or divinati…
Operant conditioning: principles, history, and practical applications Operant conditioning Operant conditioning is a learning process in which behaviour is shaped by consequences. This article explains core mechanisms, reinforcement types and schedules, history, examples…
Oppositional Defiant Disorder Oppositional defiant disorder (ODD) is a behavioral disorder marked by a persistent pattern of angry, irritable mood and argumentative, defiant, or vindictive behavior, primarily i…
Out-of-Body Experience (OBE): Overview, Causes, and Significance Out of body experience An out-of-body experience is a subjective sensation of perceiving the world from a location outside one's physical body. This article summarizes features, causes, history, and scie…
Palm reading (Chiromancy): Overview, History, Methods, and Cultural Context Palm reading Palm reading (chiromancy) interprets lines, mounts and shapes of the hand to suggest character traits or future events. It is a long-standing cultural practice without scientific v…
Panic attack A panic attack is a sudden episode of intense fear or discomfort with physical and cognitive symptoms. This article explains signs, causes, differences from general anxiety, manage…
Panic disorder: overview, symptoms, causes and treatment Panic disorder Panic disorder is an anxiety condition marked by recurrent unexpected panic attacks and persistent concern or behavioral change. It is treatable with psychotherapy, medication, and…
Pansexuality: definition, history, and distinctions Pansexuality Pansexuality is a sexual orientation characterized by attraction to people regardless of sex or gender. This article explains meaning, history, symbols, common misconceptions, and…
Paranoid Thinking: Causes, Symptoms, and Clinical Distinctions Paranoia Learn about paranoid thinking: its causes, hallmark symptoms, how clinicians distinguish it from normal fear or cultural beliefs, diagnostic considerations, and associated mental h…
Parapsychology: study of reported psychic phenomena, research, and debate Parapsychology Parapsychology examines reported psychic or anomalous experiences — such as ESP, psychokinesis, apparitions and near-death phenomena — and the scientific, historical and cultural d…
Parasomnia: Causes, Types, and Management Parasomnia Overview of parasomnias—abnormal behaviors and experiences during sleep—covering types (NREM and REM), causes, diagnosis, treatment options, safety advice, and when to seek medical…
Pareidolia: perceiving familiar patterns in ambiguous stimuli Pareidolia Pareidolia is the tendency to perceive meaningful images, sounds, or patterns—especially faces—in ambiguous or random sensory input. It reflects normal pattern recognition and diff…
Parenting: Guiding Children from Infancy to Independent Adulthood Parenting Overview of parenting: roles, tasks by developmental stage, major approaches, cultural variations, and social importance. Practical examples and common challenges for caregivers.
Pathological Liar: Overview, Characteristics, History, and Management Pathological liar A clear, neutral overview of pathological lying: definition, typical behaviors, historical notes, clinical context, causes, assessment, and approaches to management and distinction…
Pedophilia: definition, diagnosis, distinctions, and approaches Pedophilia Overview of pedophilia: clinical definition, diagnostic criteria, differences from abuse, history, and treatment options in a neutral, concise style.
Perception (psychology and cognitive science) Perception Perception is the active process by which organisms interpret sensory input to form meaningful representations of their environment, studied across psychology, neuroscience, philos…
Perceptual psychology Branch of cognitive psychology examining how organisms organize sensory input into meaningful experience, emphasizing pre-conscious processes, innate mechanisms, and applications i…
Perfectionism: definition, types, effects, and strategies for management Perfectionism Perfectionism is a tendency to set excessively high, rigid standards. This article surveys forms, causes, consequences for mental health and work, and evidence-based approaches to…
Peripheral vision: function, anatomy, and everyday importance Peripheral vision Peripheral vision is the ability to detect objects, motion and light outside the direct line of sight. This article explains its anatomy, characteristics, clinical testing, everyda…
Persistent vegetative state A persistent vegetative state is a disorder of consciousness in which wakefulness returns without demonstrable awareness; it raises distinct diagnostic, care and ethical issues.
Personal space (proxemics): boundaries, history, and social effects Personal space Personal space is the invisible area people keep around themselves. This article describes its types, origins, cultural differences, causes of invasion, and practical applications.
Personality: Traits, Theories, and Applications Personality Personality refers to the consistent patterns of thinking, feeling, and behaving that distinguish individuals. This article outlines key concepts, major theories, measurement, uses…
Personality disorder Enduring patterns of thinking, feeling and behaving that differ from cultural expectations, cause impairment, and form stable patterns; includes classification, causes, common type…
Pervasive Developmental Disorder (PDD): Overview, Types, and Management Pervasive developmental disorder Pervasive developmental disorder (PDD) is a historical umbrella term for several early-onset neurodevelopmental conditions affecting social, communication, and behavioral developme…
Philosophy of Mind Study of the nature of minds, mental events, consciousness, and their relation to the physical world; examines competing theories, methods, and links to neuroscience, psychology, a…
Phobia: causes, types, symptoms and treatment of intense fears Phobia A phobia is an excessive, persistent fear of a specific object, situation, or social setting that interferes with life. This article explains types, origins, common signs and appro…
Photographic memory (eidetic memory): overview, evidence, and distinctions Photographic memory An overview of photographic (eidetic) memory: definitions, testing methods, scientific evidence, distinctions from related phenomena, prevalence, and practical implications.
Phrenology: 19th-century theory linking skull shape to personality Phrenology Phrenology is a disproven 19th-century belief that skull shape indicates mental traits. It influenced early localization ideas but was rejected as unscientific and is now viewed as…
Physical abuse: definition, signs, effects, and prevention Physical abuse Overview of physical abuse, how it presents, its impacts on health and wellbeing, common contexts, and measures for recognition, response, and prevention.
Physical attractiveness: traits, cultural variation, and social effects Physical attractiveness Overview of physical attractiveness: common traits, biological and cultural influences, historical perspectives, social consequences, measurement, and distinctions between beauty a…
Physical disability: causes, types, and societal responses Physical disability Overview of physical disability: definitions, common forms and causes, models of understanding, assistive technologies, accessibility, legal protections and inclusive practices.
Play (behavioral activity) Play (activity) Play is voluntary, pleasure-driven behavior seen in humans and animals that supports development, learning, social bonding and creativity across ages and cultures.
Play therapy: principles, methods, uses, and professional practice Play therapy Play therapy uses play to help children express emotions, resolve problems, and develop coping skills. This article explains goals, common approaches, therapeutic techniques, setti…
Pleasure: emotional experience, types, biology, and cultural meaning Pleasure Pleasure is a basic emotional experience associated with positive sensations and reward. This article explains types, biological basis, history, uses, and distinctions from related…
Post-traumatic stress disorder: causes, symptoms, history, and treatment Post-traumatic stress disorder Overview of post-traumatic stress disorder (PTSD): defining features, symptom clusters, causes and risk factors, historical background, diagnosis, treatment approaches, and common…
Postural orthostatic tachycardia syndrome (POTS) Postural orthostatic tachycardia syndrome A disorder of autonomic regulation causing excessive heart rate increase on standing, with dizziness, fatigue, palpitations and other systemic symptoms; diagnosis and management re…
Prefrontal cortex: structure, functions, development, and clinical importance Pre-frontal cortex The prefrontal cortex is the foremost part of the frontal lobes that supports planning, decision-making, social behavior and executive control. This entry outlines its anatomy, rol…
Precognition (Premonition, Second Sight): Overview, Evidence, and Cultural Role Precognition Precognition is the purported ability to perceive future events. This article outlines the concept, typical claims, scientific appraisal, cultural role, and common non‑paranormal e…
Prejudice: definitions, forms, causes, effects and responses Prejudice An overview of prejudice: what it means, how it develops, common forms, historical and legal contexts, social effects, and strategies to reduce biased attitudes and discrimination.
Pride: meanings, expressions, and cultural perspectives Pride A concise overview of pride as an emotion and social concept — its constructive and destructive forms, historical views, common examples, and distinctions such as self-respect vers…
Primary Progressive Aphasia: a progressive language disorder Primary progressive aphasia Primary progressive aphasia (PPA) is a neurodegenerative syndrome in which language abilities gradually decline while other cognitive domains are relatively spared early on.
