Browse and explore dozens of major psychology theories

What is psychology? An overview

What is psychology and why should we study it? This short video from Macat explains how the subject has developed over the years and introduces some of the key thinkers and ideas.

Who was Freud and what did he say?

Sigmund Freud is one of the most famous psychologists and is widely cited—but do you really know the basics of what he taught? Here's a super brief breakdown of his major insights.

A full crash course in psychology

This 40-episode crash course series mirrors the curriculum of an advanced high school class on the psychology with well-known creators the Green brothers. Browse each roughly 10-minute episode or watch them all.

Explore an interactive map of the unified theories of everything

This interactive concisely describes many highly complex theories ranging from quantum gravity and black holes to dark matter and energy. Supplementary resources, key questions, and possible solutions accompany each description. As of 2026, no developed theory provides an accepted explanation of all observed phenomena in the universe at all scales.

Four psychological tools for a happier, calmer life

The perennial debate on how to be happy involves various aspects of life, and one of the most essential is our psychological attitudes toward experiences. This piece lists and explains four basic tools to strengthen your "psychological immune...

Wilhelm Wundt, the forgotten father of modern psychology

He was the first psychologist to call himself one, and he influenced a whole generation of early psychologists. Learn about the life and works of Wilhelm Wundt with this thorough entry from a philosophy encyclopedia.

Problem solving, problem recognition, and learning ability makes up intelligence

Psychologists have several theories from which the concept of intelligence is explained, including general and multiple intelligences. Although IQ is used to quantify intelligence, issues like its cultural biases have spurred debate.

Wilhelm Wundt's place in the history of psychology

While ancient philosophers considered the central problems of psychology, it was Wilhelm Wundt who first called himself one. Here's a quick video overview of his contribution.

Drugs 101: An interactive guide

What's the difference between opioids and psychedelics? This guide details specific drugs and their various associated effects. Drugs in this wheel fall into seven categories: stimulants, depressants, empathogens, psychedelics, dissociatives, cannabinoids, and opioids.

Visualizing 11 cognitive biases that influence how you think

Humans are hardwired to make mental mistakes called cognitive biases, affecting the way we view our world. Among the most common are confirmation bias (seeking only evidence that affirms your views), authority bias (overweighting things said by authority figures), groupthink (assimilating ideas to avoid conflict), and more. This quick chart gives an overview of some of the most notable ways we mislead ourselves.

Could all mental health disorders have a unifying 'p-factor'?

Some researchers have argued in the past couple decades that all mental health disorders may have a unifying dimension—a theoretical "p-factor" that is common across mental illness, but life experiences and behaviors influence if and how illness manifests. Proponents point to similarities across different disorders, while detractors argue that such connections are largely exaggerated.

How we learn: comparing classical and operant conditioning

Psychology helps us see how we learn, whether through positive reinforcement or by conditioning a response to a stimulus. Learn about these two key theories in this brief video.

Psychedelic compounds: a visual library

However psychedelic experiences manifest, they all begin with the presence of psychoactive compounds. Learn about their various chemical compositions in this structural library of psychedelic compounds. Clicking on an entry will take readers to a new page where they can learn about the chemistry and pharmacology of each compound, as well as the drug's possible applications.

Learn why modern scientific patterns have been described as theories rather than laws

After confirming that the accuracy of some laws of physics is limited to certain domains, science became more hesitant to categorize identified mathematical relationships, such as quantum mechanics, as unchanging laws. Instead, these recent, complex frameworks are designated as theories to acknowledge that they are conditional and may be part of a larger, more complete future framework.

Famed psychologist Sigmund Freud believed dreams were symbolic expressions of desire.

Why the Myers-Briggs test is pure entertainment

The world's most popular personality test isn't used by academic psychologists—but hundreds of companies and thousands of colleges use it to place workers and students. Here's why it's so popular and likely overused.

Psychology research shows that conspiracy theorists tend to have a desire to be unique

While conspiracy theorists are often understood to have feelings of powerlessness in their lives, research suggests they may also be inclined to set themselves apart from the masses.

Ranking life's biggest decisions

Psychological research presents some unsurprising wisdom about how to make big decisions without regret: focus on people, don’t miss opportunities, and stay true to yourself.

William James laid the foundation for psychology as a scientific discipline in the US

Though initially trained in painting, James would help establish Harvard's psychology department as a distinct science rather than an extension of philosophy. He taught one of the first psychology courses in America and is credited as one of the founders of American Pragmatism.

The science behind ghosts, explored

Every culture has them—restless spirits, haunted houses, things that go bump in the night. But why do we believe in ghosts? Psychologist and skeptic Dr. Chris French joins host Sony Kassam to explore the science behind the supernatural, from sleep paralysis and hallucinations to the brain’s pattern-making instincts.

See how antidepressants—used by roughly 1 in 10 Americans—were discovered.

What's the difference between a psychologist and a psychiatrist?

While both psychiatrists and psychologists are mental health professionals, the big difference is that psychiatrists are medical physicians (MD or DO) while psychologists are not. Learn what makes these two profession different with this brief explainer.

A list of five scientific theories that were accepted and later disproved

Humoral theory held that everyone's personality derived from different combinations of four bodily fluids: blood, phlegm, yellow bile, and black bile. The phlogiston theory stated that all combustible materials possessed a fire element—phlogiston—that was released and absorbed by the air during burning. When the air became saturated with phlogiston, the fire would go out.

Psychedelics interact with neurotransmitter systems to alter one's perception

LSD, psilocybin, and MDMA can suppress the brain's default mode network and enhance connectivity. Research shows that, when paired with therapy, psychedelics may help treat mental health conditions, including depression, addiction, and PTSD.

What is psychoanalysis?

This nine-minute video, the first of a four-part series, seeks to answer the questions: what is psychoanalysis, and is it weird? The answer to the latter question is overwhelmingly yes. The answer to the first question is a bit...

Who provides therapy is more important than what method they practice

What makes therapy work well is the connection that patients feel with their therapist, and the trust in that relationship. Some research suggests that while the therapeutic model—say cognitive behavior therapy or psychodynamic therapy—accounts for roughly 15% of outcomes, the therapeutic relationship with the therapist accounts for more than 30%.

A comprehensive guide to the gods

History is filled with the power and mystique of gods, from the epicly bearded Greek boss Zeus to Hoori, the Japanese god of hunting. Check out this database of over 4,000 of the world's deities, from Norse mythology to the gods of Polynesia, and click through for explainers and facts. Peruse specific pantheons (a single culture's collection of gods) or look for the god of a specific attribute, place, or emotion. Dive in here.

Carl Jung proposed the controversial idea of the 'collective unconscious'—all humans share a common psychic realm.

An encyclopedia of anthropology

This online database offers articles and additional resources for all things anthropology. This free resource is filled with peer-reviewed entries that cover topics ranging from addiction to writing, and offers anthropological insight into more...

Explore this deep dive into how SSRIs work

This 101-style explainer on selective serotonin reuptake inhibitors explains how they work in the brain—complete with classroom-style whiteboard drawings. It covers common SSRIs, why someone might try this medication, and a deeper discussion about potential side effects.

An existentialist reading list

If you’re looking for a starting point for diving into existentialist thought, this is a great resource. Its titles are not exactly obscure—Albert Camus’ “The Stranger,” Franz Kafka’s “The Trial,” and Søren Kierkegaard’s “Either/Or” are among the most famous works in Western literature—but the list provides some digestible context for each text, which will help you decide the best place to begin your journey.

Are we too attached to attachment styles?

Attachment theory was developed to help understand the impact of caregiver relationships on children. Recently, the theory has been applied to adults, categorizing them into different attachment styles. Is it accurate? This podcasts takes a closer...

The science of springtime, 101

Dive into the basics on springtime including the astronomy that brings it about, natural signs of spring's arrival, and some of the cultural approaches to the season.

How four types of psychedelics affect the brain

Brain imaging shows that ayahuasca, MDMA, DMT, and psilocybin profoundly affect neural activity, giving rise to higher states of introspection and consciousness. This article details exactly how each of these drugs physically affects the brain and what that means for mental health treatment. Some of these drugs quiet the brain or trigger the release of neurochemicals associated with mood regulation and learning.

Burnout became a serious area of study in the 1970s

Psychology professor Christina Maslach developed the first tool to assess the presence of burnout, focusing on six contributing factors within workplaces: an overwhelming workload, a lack of control over one’s work, insufficient reward for one’s efforts, interpersonal conflict, a sense of unfairness, and a mismatch between individual and organizational values.

Psychedelic side effects, including worsening mental health for some patients, give pause

This article explores whether the therapeutic potential of psychedelic drug use is really as good as current research suggests. Scientists are exploring its applications for conditions ranging from the existential crisis that can accompany terminal diagnoses to chronic mental health conditions, including anxiety and PTSD.

An interesting perspective on whether (and how) brain size matters in cognitive ability

Some brains are bigger than others, but what is the relevance, if any, to brain size and intelligence? This Scientific American article explores the question and offers examples. It also visually compares frontal slices of several mammals' brains, showing that humans don't necessarily have the biggest cerebrums on the block.

A guide to the romance genre's major tropes

This guide breaks down romance's most prominent tropes, or narrative patterns, used by romance writers and adored by their fans. After you learn about "friends to lovers," "marriage of convenience," and "forced proximity," you'll start to see your favorite romance reads in an entirely new light.

Panpsychism suggests that all matter possesses consciousness

The theory describes consciousness as a fundamental, ubiquitous property, rather than separate or emerging from matter. Cosmopsychism posits that the universe is conscious, while some critics argue that consciousness itself may be an illusion.

The basics of behaviorism and its founder John B. Watson

Watson believed he could use classical conditioning to shape the behavior of infants toward positive outcomes, culminating in his famous "Little Albert" experiment. Here's a quick overview of his life and thought.

Learn about the more than 100 known autoimmune diseases

Explore this resource with summaries and related resources for the dozens of autoimmune diseases defined in the medical literature. Many of these disease write-ups also have interviews with a patient with the disorder—offering a personal take about challenges, advice, and lifestyle effects.

Breaking down the music theory of Hitchcock's 'Psycho'

One of the defining features of Hitchcock’s film “Psycho” (1960) is the music, especially the sounds you hear during some particularly grisly scenes. This analysis from The Music Professor analyzes how that music complements the film, highlighting the way strings match the intensity of the film’s screenplay and black-and-white cinematography.

Studies of psychedelic use may help shed light on the nature of consciousness

The nature of consciousness—what it is, where it comes from, and how it manifests as moment-to-moment experience—remains under debate by scientists. Recent studies show psychedelics were found to boost low-frequency brain signals known as delta waves, a behavior also seen during dream states.

Meet the psychologist who reads people through the art they live with

Dimitrios Tsivrikos, an academic psychologist at University College London, says the art someone hangs in their home reveals as much about them as a bookshelf would. He advises going on a first date at a museum and asking each other about the work on the walls.

The commercial and therapeutic potential of psychedelics

A 2006 study into the potential therapeutic benefits of psychedelics sparked a renewed interest in the field of psychedelic research, a development that has cascaded into commercialized ventures and experiences. This article details how growing research into the psychological benefits of psychedelics is matched by the rise of anecdotal reports, book deals, businesses, and corporate claims seeking to capitalize on psychedelic potential.

View an infographic of the Standard Model

Much like this visualization, the theory serves to catalog almost all phenomena involving visible matter comprehensively, including organizing observed elementary particles by shared characteristics and explaining most fundamental forces and quantum properties.

The dreaming brain, as understood by scientists

Technology has advanced to where the seemingly separate fields of psychology and neuroscience are asking the same questions about dreams, such as whether they're more closely related to perception or visualization. Some field-intersecting findings include research that shows people with impaired face perception don't dream of faces, those with brain legion-related cognition difficulties deal with similar issues in dreams, and children's dreams change in parallel to their cognitive development.

Distinguishing between scientific theories and laws, and why both are on equal footing

Scientific laws describe outcomes of specific conditions, and scientific theories explain why those outcomes occur. Both are supported by observational and experimental data and can each inform one another, but neither can become the other. Instead, additional data can improve each towards more accurate descriptions and explanations of reality.

Scientists identify hundreds of genes responsible for OCD

Researchers analyzed the DNA of more than 53,000 people with OCD and identified 30 areas in the genome linked to the disease, containing 249 genes of interest. Of those, several were linked to other brain disorders, paving the way for genetic treatments of various mental illnesses.

The psychology of narcissism

It's not just an insult: Narcissistic personality disorder impacts thousands of people—and there are ways to get better. Here's a short video explaining it.