Psychology is the scientific study of human and animal behavior, which includes both observable actions (such as eating and speaking) and mental activities (such as remembering and imagining). Psychology tries to understand why a person or animal behaves a certain way and then seeks to predict how that person or animal will behave in the future. For many years, psychology was a branch of philosophy (the study and exploration of basic truths governing the universe, nature, life, and morals [a sense of right and wrong]). In the nineteenth century, scientific findings established it as a separate field of scientific study.
In 1879, German physiologist Wilhelm Wundt (1832–1920) established the first formal laboratory of psychology at the University of Leipzig in Germany. Wundt's work separated thought into simpler processes such as perception, sensation, emotion, and association. His approach looked at the structure of thought and came to be known as structuralism.
In 1890, American philosopher William James (1842–1910) published his Principles of Psychology. In contrast to structuralists, James thought consciousness (awareness) flowed continuously and could not be separated into simpler elements. James argued that studying the structure of the mind was not as important as understanding how it functions in helping us adapt to our surroundings. This approach became known as functionalism.
In the early 1900s, Austrian neurologist Sigmund Freud (1856–1939) began formulating psychoanalysis, which is both a theory of personality and a method of treating people with psychological difficulties. Freud's most influential contribution to psychology was his concept of the unconscious. He believed a person's behavior is largely determined by thoughts, wishes, and memories of which they are unaware. Painful childhood memories are pushed out of consciousness and become part of the un conscious. From here they can greatly influence behavior. As a method of treatment, psychoanalysis strives to bring these memories to awareness, freeing an individual from their often-negative influence.
In 1913, American psychologist John B. Watson (1878–1958) argued that mental processes could not be reliably located or measured. He believed that only observable, measurable behavior should be the focus of psychology. His approach, known as behaviorism, held that all behavior could be explained as a response to stimuli in the environment. Behaviorists tend to focus on the environment and how it shapes behavior.
Behaviorism: School of psychology focusing on the environment and how it shapes behavior.
Cognitive psychology: School of psychology that focuses on how people perceive, store, and interpret information through such thought processes as memory, language, and problem solving.
Functionalism: School of psychology that focuses on the functions or adaptive purposes of behavior.
Gestalt psychology: School of psychology that focuses on perception and how the mind actively organizes sensations.
Humanistic psychology: School of psychology emphasizing individuals' uniqueness and their capacity for growth.
Neuropsychology: Study of the brain and nervous system and their role in behavior and mental processes.
Psychoanalysis: Theory of personality and method of psychotherapy founded by Sigmund Freud.
At about the same time behaviorism arose, German psychologists Max Wertheimer (1880–1943), Kurt Koffka (1886–1941), and Wolfgang Köhler (1887–1967) founded Gestalt psychology (German for "form" or "configuration"). Gestalt psychologists argued that perception and thought cannot be broken into smaller pieces without losing their wholeness or essence. They argued that people actively organize information and that the wholeness and pattern of things dominates the way people perceive the world.
In the 1960s, American psychologists Abraham Maslow (1908–1970) and Carl Rogers (1902–1987) helped develop humanistic psychology. They felt that past psychological approaches had focused more on human weakness and mental illness. These previous approaches neglected mental strength and the potential for self-fulfillment. Maslow and Rogers believed that everyone has a basic need to achieve one's unique human potential.
Much contemporary research has taken place in cognitive psychology. This school of psychology focuses on how people perceive, store, and interpret information, studying processes like memory, language, and problem solving. Unlike behaviorists, cognitive psychologists believe it is necessary to look at internal mental processes in order to understand behavior.
Advances in the knowledge of brain and nerve cell chemistry in the late twentieth century have influenced psychology tremendously. New technologies, which have produced visual images of the human brain at work, have allowed psychologists to study exactly where specific types of mental processes occur. This emerging field has been labeled neuropsychology or neuroscience.