What Is Psychology? Research Areas, Funding, and Career Paths

Psychology is the scientific study of mind and behavior — how people (and other animals) think, feel, perceive, learn, develop, and interact, and what happens in the brain and nervous system while they do it. It is one of the largest and most publicly visible academic disciplines, spanning everything from laboratory experiments on visual perception to large-scale surveys on wellbeing to clinical trials of therapies for depression. This guide covers what psychology actually studies, its major sub-disciplines, the real research funding landscape for the field, the methods psychologists use, and typical training and career pathways — the research-administration layer that a general encyclopedia entry on psychology usually leaves out.

What psychology actually studies

Psychology sits at the intersection of biology and the social sciences. Its unifying subject is behavior — anything an organism does that can be observed or measured — and the mental processes (cognition, emotion, motivation) that produce it. That mandate is broad by design, and it is what makes psychology simultaneously a natural science, a social science, and in its applied branches, a health profession.

Three questions recur across almost every psychological sub-field:

• Description. What does a given behavior or mental process actually look like, and how does it vary across individuals, groups, development, or context? Descriptive work ranges from case studies to large normed psychometric datasets.
• Explanation. What causes a behavior or mental state — biological mechanisms (neural circuits, neurotransmitters, genetics), cognitive mechanisms (how information is represented and processed), social and environmental factors, or some combination? Most modern psychological research is explicitly biopsychosocial: it treats behavior as jointly produced by biological, psychological, and social/environmental factors rather than attributing it to any single level.
• Prediction and change. Can a behavior or outcome be predicted from earlier measurements, and can an intervention (a therapy, a training program, a policy, a design change) reliably change it? This is the question that connects basic psychological science to clinical practice, education, and organizational design.

Psychology’s core methodological commitment is that mental states and behavior can be studied empirically — through controlled experimentation, systematic observation, and validated measurement — rather than through introspection or philosophical argument alone. That commitment is what separates psychology, as an academic discipline, from its philosophical ancestor.

The origins and development of psychology

Psychology’s philosophical roots go back centuries — questions about mind, perception, and free will run through Aristotle, Descartes, and Locke — but psychology as an independent experimental discipline is conventionally dated to 1879, when Wilhelm Wundt founded the first laboratory dedicated to psychological research at the University of Leipzig. Wundt’s approach, later called structuralism, tried to break conscious experience down into its basic elements through trained introspection.

In the United States, William James’s Principles of Psychology (1890) helped establish a rival approach, functionalism, which asked what mental processes are for rather than what they are made of — a framing closer to modern evolutionary and cognitive psychology. Early in the 20th century, behaviorism (John B. Watson, later B. F. Skinner) rejected the study of unobservable internal states altogether and confined psychology to observable stimulus-response relationships; behaviorist learning theory dominated much of American academic psychology through the 1950s. A separate and largely clinical tradition, psychoanalysis, developed out of Sigmund Freud’s work on the unconscious and shaped clinical practice and popular ideas about psychology heavily, even as it had comparatively little influence on the discipline’s later experimental mainstream.

The “cognitive revolution” of the 1950s–60s reopened the mind to scientific study by treating mental processes as information processing — drawing on new work in linguistics, computer science, and neuroscience — and cognitive psychology has been a dominant paradigm since. From the late 20th century onward, advances in neuroimaging and molecular genetics pulled psychology increasingly close to neuroscience and biology, producing the biopsychosocial, multi-level explanatory style that characterizes most current research. Positive psychology, formally launched by Martin Seligman in the late 1990s, added a further strand focused on wellbeing, strengths, and flourishing rather than only on dysfunction. The discipline’s current landscape reflects all of these lineages at once: a science built from philosophy, biology, and the social sciences, still organized loosely around the same descriptive/explanatory/predictive questions it started with.

How psychology relates to neighboring disciplines

Psychology’s boundaries with several neighboring fields are genuinely blurred, and the distinctions matter for readers deciding which field’s literature, funders, or training pathway actually fits their question.

• Psychology vs. psychiatry. Psychiatry is a medical specialty: psychiatrists hold an M.D. or D.O., can prescribe medication, and are trained within medicine. Psychologists (in the research and most clinical roles) hold a doctorate in psychology, not medicine, and in most U.S. states cannot prescribe medication. The two professions overlap heavily in mental-health treatment and often work together, but they are distinct disciplines with different training pathways, licensing bodies, and (for most purposes) different professional associations — the American Psychological Association is not the American Psychiatric Association, despite the shared initials.
• Psychology vs. neuroscience. Neuroscience studies the nervous system at every level, from molecules to circuits to whole-brain systems, using methods (single-cell recording, molecular biology, connectomics) that go well beyond behavior. Biological and cognitive psychology sit at neuroscience’s behavioral end, asking how neural mechanisms produce specific psychological outcomes; see CASRAI’s neuroscience guide for the broader field.
• Psychology vs. sociology. Sociology studies groups, institutions, and social structures as its primary unit of analysis; psychology’s primary unit is the individual (even when studying groups). Social psychology is the specific sub-field where the two disciplines overlap most, and the boundary is more a matter of emphasis and training than a hard line — see CASRAI’s sociology guide for the discipline-level comparison.
• Psychology vs. economics. Behavioral economics applies psychological findings about judgment, decision-making, and self-control to economic models that traditionally assumed fully rational actors; it is now a well-established sub-field within economics that draws directly on cognitive and social psychology research. See CASRAI’s economics guide.
• Psychology vs. linguistics. Psycholinguistics studies how people acquire, produce, and comprehend language, sitting directly between cognitive psychology and linguistics; see CASRAI’s linguistics guide.
• Psychology vs. political science. Political psychology applies psychological theory (attitude formation, group identity, motivated reasoning) to political behavior — voting, polarization, ideology; see CASRAI’s political science guide.

Major sub-disciplines within psychology

Psychology is usually taught and funded as a federation of sub-fields rather than a single unified method. The major ones:

• Clinical psychology. The assessment, diagnosis, and treatment of mental illness and psychological distress; the largest applied sub-field by number of practitioners, and the training route (Ph.D. or Psy.D.) most people mean when they say “psychologist” in a treatment context.
• Counseling psychology. Closely related to clinical psychology but historically more focused on normal developmental and adjustment concerns (career, relationships, life transitions) than severe mental illness, though the practical overlap with clinical training and licensure is substantial.
• Cognitive psychology. Memory, attention, perception, language, problem-solving, and decision-making — the mental processes underlying thought, studied largely through controlled behavioral experiments and, increasingly, neuroimaging.
• Behavioral and biological (physiological) psychology. How brain structures, neurotransmitters, hormones, and genetics shape behavior; overlaps heavily with neuroscience.
• Developmental psychology. How cognition, emotion, social behavior, and personality change across the lifespan, from infancy through aging.
• Social psychology. How individuals’ thoughts, feelings, and behavior are shaped by the actual, imagined, or implied presence of others — attitudes, persuasion, group dynamics, prejudice, prosocial behavior.
• Personality psychology. Stable individual differences in thought, emotion, and behavior, including trait models (such as the Five-Factor Model) and their measurement.
• Industrial-organizational (I-O) psychology. The application of psychological principles to workplaces — personnel selection, training, motivation, leadership, organizational culture, and job performance.
• Health psychology. How psychological, behavioral, and social factors influence physical health, illness, and health-related behavior (adherence, chronic-disease self-management, stress and physiology).
• Educational and school psychology. Learning processes, instructional design, and, in school psychology specifically, assessment and intervention for students within school systems.
• Forensic psychology. The application of psychological expertise to legal and criminal-justice questions — competency evaluation, risk assessment, eyewitness testimony, and expert testimony.
• Quantitative psychology and psychometrics. The measurement and statistical methods underlying the rest of the field — test construction, reliability and validity, item response theory, and the statistical models psychologists use to analyze data. Quantitative psychologists often work across all of the sub-fields above as methodologists.

These sub-fields are not mutually exclusive in practice: a great deal of current research is explicitly interdisciplinary — developmental cognitive neuroscience, social-personality psychology, and clinical-health psychology are all common working combinations rather than exceptions.

The research funding landscape for psychology

Because psychology spans basic science, health, and social science, its funding base is unusually broad — wider than most single disciplines — and understanding which funder covers which slice of the field is a real, practical research-administration question.

In the United States, the National Institutes of Health (NIH) is the largest single funder of psychological research, though it has no single institute called “psychology.” The National Institute of Mental Health (NIMH) is the institute most central to the field: it funds more than 4,000 extramural research grants and contracts and runs its own intramural research program covering basic neuroscience and clinical investigation of mental illness, brain function, and behavior. Beyond NIMH, several other NIH institutes fund psychological research where it intersects their own health mission: the National Institute of Child Health and Human Development (NICHD) funds developmental and family research; the National Institute on Aging (NIA) funds cognitive aging and behavioral research on older adults; the National Institute on Drug Abuse (NIDA) and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) fund behavioral research on substance use; and institutes focused on specific physical-health outcomes (cardiovascular disease, cancer, diabetes) regularly fund health-psychology research on behavior change and adherence. NIH also maintains an Office of Behavioral and Social Sciences Research (OBSSR), a trans-NIH coordinating office that promotes behavioral and social science research across institutes rather than funding grants directly itself.

The National Science Foundation (NSF) is the other major federal funder, and unlike NIH it funds psychology as basic science rather than through a health-mission lens. Psychology’s home at NSF is the Division of Behavioral and Cognitive Sciences (BCS), part of the Directorate for Social, Behavioral and Economic Sciences (SBE). BCS runs core programs directly relevant to psychological research, including Cognitive Neuroscience, Developmental Sciences, Perception, Action and Cognition, Social Psychology, and the Science of Learning and Augmented Intelligence — funding basic research on the brain, cognition, language, and social behavior.

Among private foundations, the American Psychological Foundation (APF) — the charitable, grant-making arm affiliated with the American Psychological Association — funds research grants, early-career awards, and scholarships specifically within psychology. The Spencer Foundation (see CASRAI’s Spencer Foundation entry) is a major funder of education research and regularly supports developmental and educational psychology projects specifically. The Russell Sage Foundation funds social-science research broadly, including social psychology work on inequality and social behavior, and the William T. Grant Foundation is a notable funder of research on youth development and the reduction of inequality, a natural fit for developmental and social psychologists. Outside the US, national research councils play the equivalent role — in the UK, both the Economic and Social Research Council (ESRC) (see CASRAI’s ESRC dictionary entry) and, for more biologically oriented work, the Medical Research Council fund psychological research.

Research methods, tools, and data

Psychology’s methodological toolkit spans the full range from tightly controlled laboratory experiments to large observational datasets, reflecting the discipline’s span from basic cognitive science to applied clinical and organizational work.

• Experimental design. Randomized, controlled experiments — manipulating one or more variables while holding others constant — remain the discipline’s gold standard for establishing causal claims about cognition, perception, and behavior, typically run with human participants under IRB oversight.
• Psychometrics and instrument development. Much of psychology depends on validated measurement instruments — scales, questionnaires, structured interviews, and standardized tests — built and evaluated for reliability (consistency) and validity (whether they measure what they claim to) before they are used in substantive research.
• Survey and observational research. Large cross-sectional and longitudinal surveys track attitudes, behavior, and wellbeing across populations and over time, and are central to developmental, social, and health psychology in particular.
• Neuroimaging and psychophysiology. fMRI, EEG, eye-tracking, and other physiological measures let researchers connect behavior and self-report to underlying neural and bodily activity, a major growth area at the psychology-neuroscience boundary.
• Qualitative methods. Interviews, focus groups, and thematic analysis are used, particularly in clinical, counseling, and health psychology, to capture experience and meaning that structured quantitative instruments can miss.
• Statistical analysis. Regression, ANOVA, structural equation modeling, and multilevel/hierarchical models are the standard analytic toolkit, typically run in software such as SPSS, R, or Stata — see CASRAI’s SPSS vs. R and SPSS vs. Stata comparisons for how researchers commonly choose between them, and the effect size and operationalizing variables dictionary entries for two of the field’s foundational analytic concepts.

Psychology has also been central to the broader open-science and replication movement in research administration — preregistration, open data, and registered reports were adopted early and heavily within psychology following the discipline’s own high-profile replication concerns in the early 2010s, and psychology-specific preprint infrastructure (such as PsyArXiv) exists specifically because of that history.

Career and training pathways

Training in psychology diverges early depending on whether the goal is research, clinical practice, or an applied non-clinical role.

• Undergraduate degree (B.A./B.S.). A bachelor’s in psychology is common preparation for graduate study but also a general-purpose degree used across business, education, and human-services roles without further psychology training.
• Master’s degree. A terminal master’s (M.A./M.S.) supports some applied roles directly — particularly in industrial-organizational psychology and school psychology — and in some jurisdictions supports licensure as a master’s-level counselor, though this varies significantly by state/region and specialty.
• Doctoral training: Ph.D. vs. Psy.D. A research-focused doctorate (Ph.D.) trains scientist-practitioners across an original dissertation and, for clinical/counseling tracks, supervised clinical training; a practice-focused doctorate (Psy.D.) emphasizes clinical training over original research and is common specifically in clinical and counseling psychology. Both are standard entry points to independent research and, for the clinical/counseling tracks, licensed practice.
• Accreditation and licensure. In the U.S., clinical and counseling doctoral programs seeking to prepare students for licensed practice typically pursue American Psychological Association accreditation, and practicing as a licensed psychologist requires a state-issued license — generally a doctorate, a supervised predoctoral/postdoctoral internship, and a passing score on the Examination for Professional Practice in Psychology (EPPP), plus any state-specific requirements. Requirements vary by state/jurisdiction, so a specific state licensing board is the authoritative source for current rules.
• Postdoctoral training. Common on the research-academic track (as in most sciences) and, in several U.S. states, a formal requirement for clinical licensure rather than an optional career step.
• Professional societies. The American Psychological Association (APA), founded in 1892, is the largest professional and scientific organization of psychologists in the United States, spanning research, clinical practice, and education; it should not be confused with the American Psychiatric Association, a separate medical organization that shares the same acronym. The Association for Psychological Science (APS) is a separate, research-focused society oriented specifically toward psychological science and its dissemination. Both publish major journals and hold annual conferences that function as key venues for research dissemination and networking across the field.

Career destinations split broadly into academic/research positions (university faculty, government and NIH/NSF-funded research scientists), licensed clinical/counseling practice (independent practice, hospitals, community mental-health settings), and applied non-clinical roles (I-O psychologists in industry, user-experience and human-factors researchers, school psychologists, and policy or program-evaluation roles across government and the private sector).

Frequently asked questions

What is psychology in simple terms?

Psychology is the scientific study of mind and behavior — how people think, feel, and act, and why, studied through controlled experiments, systematic observation, and validated measurement rather than philosophical argument alone.

What is the difference between psychology and psychiatry?

Psychiatrists are medical doctors (M.D./D.O.) who can prescribe medication; psychologists hold a doctorate in psychology (not medicine) and, in most U.S. states, cannot prescribe. The fields overlap heavily in mental-health treatment but have separate training pathways, licensing bodies, and professional associations.

See CASRAI’s sociology guide for how psychology’s individual-level focus compares with sociology’s focus on groups and social structures.

Who funds psychology research?

In the U.S., primarily NIH (led by NIMH, with contributions from NICHD, NIA, NIDA, NIAAA, and other institutes depending on the health outcome studied) and NSF (through its Division of Behavioral and Cognitive Sciences). Private foundations including the American Psychological Foundation, the Spencer Foundation, the Russell Sage Foundation, and the William T. Grant Foundation fund specific slices of the field; national research councils such as the UK’s ESRC play an equivalent role outside the U.S.

What jobs can you get with a psychology degree?

Destinations range from academic/research positions and licensed clinical or counseling practice to applied non-clinical roles such as industrial-organizational psychology, school psychology, human-factors/UX research, and program evaluation — the specific path depends heavily on degree level (bachelor’s, master’s, or doctorate) and sub-field.

Is psychology a science?

Yes — psychology is an empirical science built on controlled experimentation, systematic observation, and validated measurement, though its subject matter (mind and behavior) and methodological mix (experimental, correlational, and qualitative) span both natural-science and social-science traditions.

Related CASRAI guides

This guide is part of a series covering major academic and scientific disciplines for researchers and research administrators. See the overview of the branches of science for how psychology fits alongside other fields, and the companion guides to sociology, economics, political science and linguistics for the disciplines psychology borders most closely. For the biological end of the field, see CASRAI’s guides to neuroscience and genetics (behavioral genetics), and for shared methodological territory, the guides to epidemiology (psychiatric and behavioral epidemiology) and biostatistics (shared quantitative methods).