What is psychology? Psychology is the study of people: how they think, act, react and interact, and of the thoughts, feelings and motivation underlying that behavior. It covers both research, which builds fundamental knowledge about human and animal behavior, and practice, in which that knowledge is applied to real problems, from treating mental illness to improving schools and workplaces. 1 , 2 Last updated August 9, 2026 · 28 cited sources What are the main branches of psychology? How is psychology used in everyday life and business? Why do we feel and react the way we do, according to psychology? How does color affect our mood and behavior? What shapes personality according to psychologists? How did psychology develop as a science? What does it take to study or work in psychology? If you need support now Explore the library Common questions Most read this month What other readers are opening most across this topic right now. Why Are Some People So Angry: The Psychology Behind Chronic Anger Explore the biological, psychological, and social factors behind persistent anger, and learn effective strategies for managing chronic anger patterns. Critical Personality Traits: Understanding the Psychology Behind Judgmental Behavior Discover why people are critical of others, psychology reveals links to insecurity, perfectionism, and projection. Learn to recognize and break the pattern. Orange Color Psychology: Unveiling the Vibrant Impact on Emotions and Behavior Discover orange color psychology: how this vibrant hue influences emotions, appetite, and behavior across cultures. Learn why brands and designers choos... Psychology Terms for Behavior: A Comprehensive Guide to Understanding Human Actions Explore key psychology terms for understanding human behavior, covering cognitive, social, developmental, and abnormal psychology concepts. Evolutionary Psychology: Understanding Human Behavior Through Natural Selection Explore evolutionary psychology's foundations, theories, and applications in understanding human behavior, cognition Psychology of Eating: Understanding the Complex Relationship Between Mind and Food Discover the complex relationship between mind and food. Learn about emotional eating, hunger cues, eating disorders, and strategies for healthy eating habits. What are the main branches of psychology? Psychology splits into subfields according to which part of life they examine. Developmental psychologists study how people grow and adapt across the lifespan and use that work to help with developmental difficulties. Experimental psychologists investigate the processes behind human and animal behavior. Health psychologists work on promoting health, preventing illness and improving health care. Forensic and public service psychologists apply the same science to courts and public safety organizations, on questions ranging from mental competence to the reliability of testimony from young people. 3 , 2 , 4 , 5 , 6 Other branches are defined by the setting rather than the life stage. Clinical psychologists assess and treat mental, emotional and behavioral disorders, from short-term crises to severe chronic conditions such as schizophrenia. Counseling psychologists focus on how people interact with their environment and on educational and career development. Social psychologists study how individuals affect and are affected by other people and by their surroundings, including prejudice, implicit bias, bullying and substance misuse. Industrial and organizational psychologists study workplaces in order to improve productivity, satisfaction, safety and health. Within any of these areas some people work mainly as researchers, some mainly as practitioners, and many do both. How is psychology used in everyday life and business? Psychologists turn up in far more places than the therapy room. They work in laboratories, hospitals, courtrooms, schools and universities, community health centers, prisons and corporate offices, often alongside physicians, lawyers, engineers, policymakers and managers. That means helping patients change behaviors that damage their physical health, working with business executives, performers and athletes to reduce stress and improve performance, advising lawyers on jury selection, and working with educators on school reform. 7 , 6 In business, industrial and organizational psychologists use workplace observation, surveys and other quantitative methods to work out why things go wrong. Problems with communication, conflict resolution, process evaluation and management can often be traced back to how employees are selected, trained, share information or interact with each other. Their work covers applicant and employee testing, leadership development, staffing, teams, compensation, workplace safety, diversity and work-life balance. In sport, psychologists help athletes sharpen their focus on competition goals, build motivation, and handle the anxiety and fear of failure that come with competing. Why do we feel and react the way we do, according to psychology? A great deal of current thinking about emotion centers on the amygdala, a small structure deep in the brain. It takes part in several processes involved in working out what a stimulus is and what you should do about it, spanning attention, judging how much something matters, and decision making. Work with both animals and people points to a prominent role in the rapid detection and recognition of information that is critical for survival. 8 , 9 The amygdala was once described as a fear module, but that picture has narrowed too far. Brain imaging has struggled to show that it responds only to fear. When people are scanned while looking at faces, every part of the amygdala responds to fearful, angry and happy expressions alike, which suggests that whatever is special about its role in fear may lie in how it connects with the rest of a face-processing network rather than in its own local activity. How does color affect our mood and behavior? Color changes how a space feels, though the effects are more modest and more mixed than popular accounts suggest. When people judge images of identical living rooms that differ only in color, warm colors are rated as more arousing, exciting and stimulating, while cool colors are rated as less arousing but more spacious and restful. People also report more tension, anger, depression and anxiety, and less visual comfort and calmness, in a red room than in a white one. 10 , 11 , 12 , 13 One proposed explanation is that light and color influence activity in brain regions tied to emotion and mood, including the amygdala and hypothalamus, and that a color's hue, brightness and saturation each act differently on the nervous system. The links people make between colors and emotions also appear fairly stable across the lifespan. Comparisons of adults from their teens to their eighties, across many countries, find that different age groups show very similar patterns, with adolescents linking the greatest number of emotions to colors and older adults linking fewer but more intense and more positive ones. Even so, important weaknesses remain in both the theory and the evidence on color and psychological functioning. What shapes personality according to psychologists? Both inheritance and experience shape personality, and neither one accounts for most of it on its own. Most behavioral characteristics are heritable to some degree, and studies of twins consistently attribute roughly half of the differences between people's personalities to genetic effects. The remainder is generally attributed not to the shared family household but to the environments that make people within the same family different from one another. 14 , 15 , 16 Those estimates treat genetic and environmental contributions as fixed values for a whole population, and newer approaches ask whether heritability itself shifts depending on the environment. Genes and environments are also tangled together rather than separate: your genetic makeup influences the situations you put yourself into, and it can also change how strongly a given situation affects your behavior. Alongside this, developmental psychologists have long recognized the part played by family environment, particularly parenting style, parental monitoring and the parent-child relationship, in how temperament and personality develop. How did psychology develop as a science? Modern psychology is usually dated to 1879, when Wilhelm Wundt opened his laboratory in Leipzig, and researchers who have revisited the question argue that this founding moment should still be dated there. There were earlier attempts to establish psychology as an independent discipline in the late eighteenth century, notably at the newly founded University of Munster, where Ueberwasser has been described as the first academic to consider himself a psychologist. 17 , 18 , 19 Other pioneers of experimental approaches to psychological questions, such as Weber, Fechner and Helmholtz, did not consider themselves psychologists, while Ueberwasser and Wundt explicitly portrayed themselves as psychologists and sought to establish psychology as a field of its own. The methods came first. In 1862 Wundt tried to measure the speed of thought by tracking the gap between where a swinging pendulum actually was and where people perceived it to be, and by 1879 he had invented the reaction time experiment, presenting a tone or a light and timing how long people took to press or release a button. His aim was to identify and measure the elemental processes that are the basic ingredients of mental life, and his basic approach is still standard: observe something physical, such as a reaction time, a verbal report or a bodily response, and record how it varies across time or context. Whether those findings hold up on repetition has become a live question. When researchers sought to replicate the effects of 100 psychology studies, 97 percent of the originals had produced statistically significant results but only 36 percent of the replications did. Replication studies have historically been rare because journal editors and reviewers valued them less than original research, though funding agencies and publishers have since adopted policies encouraging replication and reproducible work. What does it take to study or work in psychology? Becoming a licensed psychologist is a long haul. The typical route runs from four years of undergraduate study to four to six years of graduate school ending in a PhD or PsyD, then a one-year full-time internship and national and state examinations. Most states also require a further year of supervised practice, so the whole path can take eight to 12 years or more. To practice you must be licensed through your state's licensing board, although people working at a university, a state or federal institution, a research laboratory or a corporation may be exempt in some states. 20 , 21 , 4 , 22 , 23 , 7 , 1 Graduate training covers biological, cognitive, emotional and social aspects of behavior, individual differences, theories of counseling and personality, psychological assessment, psychopathology, measurement and statistics, research design and professional ethics, alongside supervised clinical work. The doctorate, whether a PhD, PsyD or EdD, is recognized as the minimum educational requirement for psychologists, and the PsyD exists specifically for students who want to do clinical work rather than research. Someone working in psychology with a master's degree is usually supervised by a person with a doctorate. Not everyone who studies psychology practices it: most people holding a bachelor's degree in psychology work in areas other than psychology, and only a small proportion of psychology graduates go on to work with patients. Explore the library Everything we have written on this topic, grouped by what you might be looking for. Understanding psychology basics Core definitions, terms and everyday facts that explain the field to beginners. Psychology Fun Facts: 25 Mind-Blowing Insights into Human Behavior Psychology Terms for Behavior: A Comprehensive Guide to Understanding Human Actions Psychology Questions: Fascinating Insights into the Human Mind Psychology Questions and Answers: Exploring the Human Mind Psychological Facts: Surprising Insights into Human Behavior and Cognition Psychological Facts About Introverts: Unveiling the Inner Workings of Quiet Minds Awareness in Psychology: Definition, Types, and Importance Mental Processes in Psychology: Defining the Core of Human Cognition Pedagogy in Psychology: Exploring Educational Theory and Practice Psyche in Psychology: Exploring the Core of Human Consciousness Psychological Well-Being: Definition, Components, and Importance for Mental Health Branches and types of psychology A tour of the major subfields, from social and cognitive to forensic and developmental psychology. Social Psychology: The Science of Human Interaction and Behavior Experimental Psychology: Origins, Methods, and Modern Applications Environmental Psychology Theories: Exploring Human-Environment Interactions Behavioral Psychology: Principles, Applications, and Impact on Modern Life Developmental Psychology: Exploring Human Growth and Change Throughout Life Abnormal Psychology: Exploring the Complexities of Human Behavior Abnormal Psychology Examples: Exploring Types and Real-Life Cases Forensic Psychology: Bridging Law and Mental Health Social Psychology Theories: Exploring the Core Concepts Shaping Human Behavior Evolutionary Psychology: Understanding Human Behavior Through Natural Selection Forensic Psychology Work Environment: Navigating Careers in Criminal Psychology Cognitive Psychology Concepts: Key Theories and Applications in Modern Research Environmental Psychology: Understanding Human Behavior in Relation to Physical Surroundings Positive Psychology Theories: Enhancing Well-being and Personal Growth Developmental Psychology Timeline: Key Stages and Milestones from Birth to Late Adulthood Psychology in everyday life and business How psychological principles play out in marketing, gambling, food and driving decisions. Retail Psychology: How Stores Influence Consumer Behavior and Boost Sales Consumer Psychology: Unveiling the Science Behind Buying Decisions Advertising Psychology: Unveiling the Science Behind Persuasive Marketing Marketing Psychology: Leveraging Consumer Behavior for Effective Campaigns Casino Psychology: The Science Behind Gambling Behavior and Casino Design Psychology of Driving: How Our Minds Influence Our Behavior Behind the Wheel Psychology of Home: How Our Living Spaces Shape Our Minds and Behaviors Shopping Psychology: The Science Behind Consumer Behavior and Decision-Making Gambling Psychology: The Science Behind Risk-Taking and Addiction Psychology of Eating: Understanding the Complex Relationship Between Mind and Food Subliminal Advertising Psychology: Unveiling the Hidden Persuasion Tactics Packaging Psychology: How Product Design Influences Consumer Behavior Retail Therapy Psychology: Exploring Stress Shopping and Its Effects Psychology of Branding: How Brands Influence Consumer Behavior and Decision-Making Behavior Patterns in Psychology: Decoding Human Actions and Reactions The psychology of anger and difficult emotions The mental patterns behind anger, conflict and other hard-to-explain emotional reactions. Why Are People So Angry: The Psychology Behind Modern Rage Why Do I Go Silent When Upset: The Psychology Behind Emotional Shutdown Why Do I Get Angry When Someone Is Trying to Help Me: The Psychology Behind Help-Rejection Why Do I Shut Down Emotionally During Arguments: The Psychology Behind Emotional Withdrawal Why Do I Get Angry When I Get Hurt: The Psychology Behind Pain and Rage Why Do I Laugh When I’m Mad: The Psychology Behind Laughing When Angry Psychology Behind Breaking Things When Angry: Uncovering the Rage Response Psychology Behind Hanging Up on Someone: Exploring Communication Breakdown Why Are Some People So Angry: The Psychology Behind Chronic Anger What Makes People Mad: The Psychology Behind Human Anger Why Do I Get So Anxious When Someone Is Mad at Me: The Psychology Behind Conflict Anxiety Why Do I Lash Out in Anger: The Psychology Behind Explosive Reactions Throwing Things When Angry: The Psychology Behind Destructive Behavior Do People Mean What They Say When Angry? The Psychology Behind Heated Words What Does It Mean to Be Angry: The Science and Psychology Behind This Complex Emotion Someone Who Enjoys Making Others Angry: Psychology Behind Provocative Behavior What Causes Bitterness in a Person: The Psychology Behind Emotional Resentment Why Do I Smile When I’m Angry: The Psychology Behind Contradictory Facial Expressions Why Do I Never Get Angry: The Psychology Behind Emotional Suppression Why Does Cleaning Make Me Angry: The Psychology Behind Cleaning-Related Frustration Psychology of color and mood Why certain colors feel calming, angry or depressing according to psychology. Is Red a Calming Color? The Surprising Psychology Behind Red’s Effect on Mood Color Psychology: The Powerful Impact of Hues on Human Behavior and Marketing

Color Psychology: How Hues Influence Human Behavior and Emotions Orange Color Psychology: Unveiling the Vibrant Impact on Emotions and Behavior Bedroom Color Psychology: How Your Choices Affect Mood and Sleep Green Color Psychology: Exploring the Impact of Nature’s Hue on Human Behavior Purple Mood Psychology: How This Royal Color Influences Your Emotions Carl Jung’s Color Psychology: Exploring the Depths of Chromatic Symbolism Pink Color Psychology: Unveiling the Emotional Impact and Cultural Significance Periwinkle Color Psychology: Unveiling the Emotional Impact of This Soft Hue Black Personality: Unveiling the Psychology Behind Color Preferences Paint Color Psychology: How Your Walls Influence Your Mood and Behavior Personality types and traits Personality theories, traits and types explored through a psychological lens. Carl Jung’s Psychological Types: A Deep Dive into Personality Theory Personality Inventory in Psychology: Definition, Types, and Applications Personality Traits of a Gambler: Unveiling the Psychology Behind Risk-Taking Behavior Alfred Adler’s Personality Theory: A Comprehensive Exploration of Individual Psychology Arrogant Personality Psychology: Unveiling the Complexity Behind Superiority Complexes Critical Personality Traits: Understanding the Psychology Behind Judgmental Behavior Personality Traits Needed to Be a Psychologist: Essential Qualities for Success in the Field Handwriting Psychology: Decoding Personality Traits Through Penmanship Social and Personality Psychology: Unraveling the Complexities of Human Behavior Skinner’s Personality Theory: Exploring Behaviorism and Its Impact on Psychology Gordon Allport’s Theory of Personality: A Comprehensive Exploration of Trait Psychology Exhibitionist Personality Traits: Unveiling the Psychology Behind Public Display Typology Psychology: Exploring Personality Classification Systems Masculine and Feminine Traits in Psychology: Exploring Gender Characteristics Psychology of Self: Exploring the Core of Human Identity and Behavior History, theories and key thinkers The historical development of psychological thought and the theorists behind it. History of Psychology: From Ancient Philosophies to Modern Science Psychology’s Evolution: Key Changes and Shifts in Approach Over Time Psychology Philosophers: Pioneers Who Shaped Modern Thinking Psychology Approaches: Exploring the Major Theoretical Frameworks in Mental Health Theoretical Approaches in Psychology: Foundations, Applications, and Impact Modern Psychology’s Evolution: A Comprehensive History from the 19th Century to Today 50 Psychology Classics: A Journey Through Influential Psychological Works Psychology Theories List: Comprehensive Guide to Major Psychological Concepts Classics in the History of Psychology: Groundbreaking Studies That Shaped the Field Timeline of Psychology Approaches: Evolution of Mental Health Theories Psychology and Philosophy: Exploring the Intersection of Mind and Thought Child Psychological Development: Key Stages and Influencing Factors Studying and working in psychology Courses, career paths and professional skills for psychology students and practitioners. Psychology Study Requirements: Essential Subjects for Aspiring Psychologists Psychology 101 Syllabus: Essential Topics and Course Structure for Beginners Psychology Supervision: Essential Practices for Professional Development and Client Care Psychology Portfolio: Building a Compelling Showcase of Your Professional Journey Psychology Career Options: Diverse Paths for Aspiring Mental Health Professionals Psychology Data Analyst: Bridging Mental Health and Statistical Insights Psychology Volunteering: Opportunities to Make a Difference in Mental Health Psychology Club: Fostering Growth and Community for Aspiring Mental Health Professionals Psychology Student Volunteer Opportunities: Enhancing Your Education and Career Prospects Psychology Student Syndrome: Navigating Self-Diagnosis and Professional Growth Psychology in Education: Enhancing Learning and Development in the Classroom Psychological Testing Administration: Qualified Professionals and Their Roles More on Psychology Everything else in this library that is not featured in a collection above. Female Exhibitionism: Psychological Insights and Societal Implications Women with Multiple Partners: Exploring the Psychological Aspects Feet Addiction: Exploring the Psychology and Impact of Podophilia Seeing the Same Number Everywhere: The Psychology Behind Numerical Patterns Finding Fault in Others: The Psychology Behind Criticism and Judgment Psychology of Repeating Yourself: Causes, Consequences, and Coping Strategies Peeing on Someone: Psychological Interpretations and Cultural Perspectives Self-Punishment Psychology: Understanding Why We Inflict Pain on Ourselves Crying Easily: Psychological Insights into Heightened Emotional Sensitivity Psychological Effects of Locking a Child in a Room: Long-Term Consequences and Impacts Psychological Effects of Absent Parents: Long-Term Impact on Children’s Well-being The Psychology of Stupidity: Unraveling the Complexities of Human Folly Psychology of Not Using Someone’s Name: Unspoken Meanings and Social Implications Why Are Some People So Angry: The Psychology Behind Chronic Anger Common questions Is psychology a science? Yes. One of psychology's most distinctive features is that it couples science and practice, with research producing fundamental knowledge about behavior and practitioners applying it, and graduate training places a heavy emphasis on research and scientific methods. 2 , 22 What is the difference between psychology and psychiatry? A psychiatrist is a medical doctor who has been through medical school and a residency in psychiatry, and who can prescribe medication and other medical treatments as well as provide psychotherapy. Psychologists are not usually medically qualified, generally cannot prescribe or order tests such as blood work or imaging, and hold a doctoral degree such as a PhD, PsyD or EdD instead, though in some US states they can prescribe with additional training. 25 , 1 , 20 , 22 What is the difference between psychology and psychotherapy? Psychology is a discipline concerned in the first instance with the normal functioning of the mind, including learning, memory and how children develop, while psychotherapy is a form of treatment. A psychotherapist may be a psychiatrist, a psychologist or another mental health professional who has taken further specialist training, and a growing number come from outside these fields with in-depth psychotherapy training instead. 1 Can you study psychology without a science background? Often yes. The usual route starts with a bachelor's degree in psychology, and most graduate programs encourage one, but some accept applicants whose undergraduate degree is in another discipline. 23 What are some common psychology myths? Psychological myths are beliefs about human behavior that conflict with the scientific evidence but enjoy wide social support, and they are stubborn, resistant to change and common even among students and professionals in the field. A related group, neuromyths, are misconceptions about the brain, learning and memory, and they are widely believed in education across Europe, North and South America, China and elsewhere. 26 , 27 How many branches of psychology are there? There is no single agreed number, because subfields are defined by what they study rather than by a fixed list. The main ones include developmental, experimental, clinical, counseling, social, health, forensic and public service, and industrial and organizational psychology. 3 , 2 , 4 , 5 , 6 What is the difference between clinical psychology and mental health counseling? A counselor or therapist holds a master's degree in a mental health related field and is qualified to evaluate a person's mental health and use therapeutic techniques such as talk therapy, helping people cope with life challenges such as stress, relationship problems and career concerns. A psychologist holds a doctoral degree and often has extensive training in psychological research or clinical practice. Among psychologists, a clinical psychologist focuses more on psychopathology, whereas a counseling psychologist helps people address emotional, social and physical stressors. The two professions also follow separate credentialing routes. 20 , 25 , 28 Why do certain colors affect our mood? One suggested reason is that light and color affect activity in brain regions involved in emotion and mood, including the amygdala and hypothalamus, with a color's hue, brightness and saturation each acting differently on the body. This is an area where the theory and the evidence both still have significant weaknesses. 11 , 13 Every claim on this page is linked to a source we have checked. If you spot something out of date, please tell us. 1. Differences between psychology, psychiatry and psychotherapy NHS Health Careers 2. Psychology careers guide American Psychological Association 3. Psychology subfields American Psychological Association 4. Pursuing a Career in Counseling Psychology American Psychological Association 5. Pursuing a Career in Social Psychology American Psychological Association 6. Pursuing a Career in Industrial and Organizational Psychology American Psychological Association 7. Psychology careers guide (careers section) American Psychological Association 8. Emotion and Cognition and the Amygdala: From what is it? to what's to be done? PubMed Central (National Library of Medicine) (2021) 9. Specialization of amygdala subregions in emotion processing PubMed Central (National Library of Medicine) (2024) 10. Effects of interior colors on mood and preference: comparisons of two living rooms PubMed (National Library of Medicine) (2011) 11. Effect of warm/cool white lights on visual perception and mood in warm/cool color environments PubMed Central (National Library of Medicine) (2021) 12. A comparative analysis of colour-emotion associations in 16-88-year-old adults from 31 countries PubMed (National Library of Medicine) (2023) 13. Color and psychological functioning: a review of theoretical and empirical work PubMed (National Library of Medicine) (2015) 14. Genetic and environmental influences on human behavioral differences PubMed (National Library of Medicine) (1998) 15. The Heritability of Personality is not Always 50%: Gene-Environment Interactions and Correlations between Personality and Parenting PubMed Central (National Library of Medicine) (2008) 16. Behavioral genetics of personality PubMed (National Library of Medicine) (2005) 17. Should We Pre-date the Beginning of Scientific Psychology to 1787? Frontiers in Psychology, via PubMed Central (2018) 18. Understanding the Mind by Measuring the Brain: Lessons From Measuring Behavior PubMed Central (National Library of Medicine) (2009) 19. Replicability and Reproducibility in Comparative Psychology Frontiers in Psychology (2017) 20. Psychologist: What They Do, Specialties and Training Cleveland Clinic (2022) 21. What you need to know to get licensed American Psychological Association (2004) 22. What Is the Difference Between Psychologists, Psychiatrists and Social Workers? American Psychological Association (2017) 23. Pursuing a Career in Clinical or Counseling Psychology American Psychological Association 24. 988 Suicide & Crisis Lifeline Substance Abuse and Mental Health Services Administration 25. What is Psychiatry? American Psychiatric Association 26. Myths in psychology: psychological misconceptions among Spanish psychology students PeerJ, via PubMed Central (2022) 27. Prevalence of neuromyths among psychology students: small differences to pre-service teachers PubMed Central (National Library of Medicine) (2023) 28. Requirements Related to the Practice of Counseling (Provision of Mental Health Counseling Services Under TRICARE) National Academies Press, via NCBI Bookshelf (2010)