Psychology

Psychology is the scientific study of mind and behaviour, encompassing perception, cognition, emotion, development, personality, and social interaction, and spanning biological, individual, and social levels of analysis.

Scope

The discipline includes experimental and cognitive psychology, biological and physiological psychology, developmental, social, personality, clinical, and applied (educational, organizational, health) branches. It combines controlled experiments, psychometrics, observation, and increasingly neuroscience to describe, explain, predict, and influence behaviour.

Sub-topics

• Animal Experimental & Comparative Psychology
• Cognitive Psychology & Intelligent Systems
• Communication Systems
• Consumer Psychology
• Developmental Psychology
• Educational & School Psychology
• Engineering & Environmental Psychology
• Forensic Psychology & Legal Issues
• General Psychology
• Health & Mental Health Personnel Issues
• Health & Mental Health Treatment & Prevention
• Human Experimental Psychology
• Military Psychology
• Organizational Psychology & Human Resources
• Personality Psychology
• Physiological Psychology & Neuroscience
• Psychological & Physical Disorders
• Psychology & the Humanities
• Psychometrics & Statistics & Methodology
• Social Processes & Social Issues
• Social Psychology
• Sport Psychology & Leisure

Core questions

• How do people perceive, learn, remember, and think?
• How do biology and environment jointly shape behaviour?
• How do individuals develop across the lifespan?
• What explains differences in personality and ability?
• How can psychological knowledge relieve distress and improve wellbeing?

Key concepts

• Consciousness
• Conditioning and reinforcement
• The unconscious
• Information processing
• Memory and attention
• Motivation
• Development
• Individual differences

Key theories

Foundations of scientific psychology

Wundt established the first experimental psychology laboratory and a science of immediate experience; James's Principles framed enduring problems of consciousness, habit, and emotion.

Psychoanalysis

Freud proposed a dynamic unconscious, psychosexual development, and defence mechanisms, profoundly influencing clinical psychology and culture if not experimental method.

Behaviourism

Watson redefined psychology as the objective study of behaviour, and Skinner's operant analysis showed how consequences shape responses, dominating mid-century psychology.

The cognitive revolution

Miller's work on information-processing limits and Neisser's synthesis re-established the mind as a legitimate object of scientific study, modelling cognition as information processing.

Humanistic psychology

Maslow's hierarchy of needs and emphasis on growth and self-actualization offered a 'third force' beyond psychoanalysis and behaviourism.

History

Scientific psychology began with Wundt's Leipzig laboratory (1879) and James's Principles (1890). Psychoanalysis (Freud) and behaviourism (Watson, Skinner) dominated the early-to-mid twentieth century, the latter restricting study to observable behaviour. The 'cognitive revolution' of the 1950s-1960s (Miller, Neisser, Chomsky) restored mental processes to the centre, and from the late twentieth century cognitive neuroscience integrated psychology with the brain sciences.

Debates

Nature versus nurture

A recurring question is the relative contribution of genetic endowment and environment to behaviour and ability; the modern consensus emphasizes their interaction.

The replication crisis

Many classic findings have proven difficult to reproduce, prompting reforms in methods, statistics, and research transparency.

Key figures

• Wilhelm Wundt
• William James
• Sigmund Freud
• John B. Watson
• B. F. Skinner
• Abraham Maslow
• George A. Miller
• Ulric Neisser

Seminal works

• wundt-1874
• james-1890
• watson-1913
• skinner-1938
• miller-1956
• neisser-1967

Frequently asked questions

Is psychology a science?

Yes; psychology uses systematic observation, experimentation, and statistical inference. Some areas (e.g., psychoanalysis) are more interpretive, and the field actively debates methodological rigour.

What is the difference between psychology and psychiatry?

Psychiatry is a medical specialty that can prescribe drugs and treats mental illness clinically; psychology is a broader science of mind and behaviour, of which clinical psychology is one applied branch.