Even since human beings began interacting with each other, individuals have striven to understand these relationships and human behavior. The formal study of human behavior can be traced back to ancient times, during which philosophers like Plato began to describe psychology. Over time, the study and practice of psychology has changed into what we now associate with a psychology career.

Until 1879, psychology was studied as part of the field of philosophy. The ancient Greeks and the ancient Egyptians were the first to begin to describe human nature. It seems that this study began as an attempt to understand and define the human soul. This then diverged into a study of the physiological factors that influence human behavior. As this understanding of physiological factors developed, certain civilizations began to recognize the need for institutions to treat individuals with mental illnesses. As early as the eighth century, individuals could be institutionalized for “diseases of the mind.” The first of these asylums was reported in Morocco.

As the understanding of the human mind grew, there began a debate as to whether the field of psychology should truly be a subset of the field of philosophy. Some argued that, because human behavior could not be mathematically expressed, it could not be a true science of its own. This debate sparked some of the earliest formal laboratory research in the field. In the late nineteenth century, Wilhelm Wundt created the first laboratory to study psychology.

Around the same time period, individuals were also beginning to practice clinical psychology. Beginning in the 1890s, Sigmund Freud began to apply techniques such as hypnosis to help individuals with “hysteria.” His approach to treatment was termed psychoanalysis. The primary focus of psychoanalysis is to understand factors that influence the ego, which should, ultimately, help individuals understand their choices in everyday life.

Carl Jung, who originally worked with Freud, splintered off and focused on four mental functions that he believed defined the ego. These four functions were described as sensation, feelings, intellect, and intuition. Jung differed from Freud in another way as well. Jung believed that the practice of clinical psychology should be based on empirical research evidence as opposed to the anecdotal information that Freud’s theory derived from.

Soon psychology research laboratories were being built in the United States as well. In the 1880s, several of these laboratories were functioning at major universities, like the University of Pennsylvania, Indiana University, the University of Wisconsin, Clark University, and the University of Nebraska. A major evolution of this field of study took place in 1924, when Princeton University built Eno Hall specifically for the study of experimental psychology, thus becoming the first true university to have a department of psychology.

Soon, there were so many practitioners and researchers that it was necessary for them to join together and form an association to better coordinate and report on research endeavors. G. Stanley Hall invited over thirty psychologists and philosophers to Clark University, founding the American Psychological Association (APA). Their first annual meeting was held one year later at the University of Pennsylvania in 1893. Because the APA blended experimental psychology with philosophy, tension amongst its members was inevitable. Ultimately, the members of the APA with a philosophical focus left to form their own professional associations.

As more research in psychology was completed, medical journals dedicated to reporting the results of this research were developed. The first to develop was a natural offshoot of the APA, called the American Journal of Psychology. By 1894, some were unhappy with the journal’s practices and founded a new journal, Psychological Review. The Psychological Review quickly grew to be the premier journal for psychological research.

Rapidly, the field and practice of psychology began to evolve, and many different theories of practice were utilized. The theory of behaviorism began to develop as the dominant theory of psychology in the United States, having been influenced by the twentieth-century evolution of psychology in Europe. One major reason for this dominance was that research showed this to be an effective method of understanding and treating disorders of human behavior.

As always, there were individuals who did not agree with this research and practiced using other principles of psychology. These individuals included Abraham Maslow and Carl Rogers. Maslow created the hierarchy of human needs, and Rogers developed client-centered therapy. These humanistic psychologists rejected the notion that human behavior needed to be quantified in the laboratory and posited that doing so really stripped the soul away and prevented psychologists from truly understanding the human mind.

The study of psychology has been evolving since ancient times and will likely continue to change as we gain a greater understanding of the workings of the human brain. Overall, the goal has always been to understand human behavior and treat mental illness.