Since its inception in the late nineteenth century, the field of psychology has undergone various revolutions and transformations: From Freud’s psychoanalysis to modern approaches to Cognitive Behavioral Therapy (CBT), diverse schools of thought have emerged, each with its own best practices and theoretical frameworks toward therapy.

Yet with all of these developments, some within and outside of the field have argued that psychology is, in fact, not a science. These hardline empiricists claim that psychology is, at best, a convincing form of pseudoscience. Either way, much is at stake for clinical psychologists and academics as well as for mental health professionals.

Evidence-based Practice for Mental Health Professionals

One way to test whether psychology can be considered a science is to first define what one means by “science.” Broadly speaking, science is really two things: First, the cannon, or the collection of accumulated knowledge over the centuries, and second, the process of obtaining that knowledge. The former remains straightforward; however, the latter needs more explanation.

The scientific process is comprised of the following six elements:

Observable. Phenomena, whether in physics or in psychology, need to be observed. This first step already distinguishes psychology from the humanities. Take philosophy, for instance. The Platonic idea of forms remain a total abstraction. In psychology, by contrast, behaviors need to be observed to be studied.

Measurable. After making observations, phenomena are measured. In the so-called “hard” sciences like biology and geology, measurements are taken to ensure accuracy and confirm predictions. Psychology, too, measures the phenomena it studies.

Repeatable. Results need to be repeated. If phenomena are observed in one instance but can’t be confirmed, a healthy skepticism is warranted. Outliers occur in nature, so consistent results are required to separate trends from random noise. Peer review, a professional tool used by all in the social and behavioral sciences, remains one way to ensure accuracy and consistency.

Quantifiable. The truism, “Mathematics is the language of science,” remains true. Academic and clinical psychologists rely on statistics to quantify and test claims.

Testable. If claims can’t be tested, they remain unfalsifiable and are therefore bunk. Speculation has a useful, but limited, role in science. Karl Popper, the philosopher of science, helped to pioneer the idea that claims need to be potentially proven false in order to have any legitimacy. Parapsychologists, for example, who claim to study supernatural phenomenon, can’t prove or disprove many of their claims. The aforementioned Platonic forms, too, can’t be falsified and are therefore not scientific. Psychologists, however, regularly design rigorous studies that can potentially falsify their ideas.

Predictable. Science makes accurate predictions. If claims are testable and repeatable, an element of predictability, too, ought to follow.

Mental health professionals and clinicians who base their practices and interventions on evidence obtained through the abovementioned means are, in fact, engaging in a form of evidence-based practice, which is the foundation of all science.

Psychology as Science

From alchemy came the science of chemistry. From astrology came the science of astronomy . . .

Many well-established sciences have shaky beginnings, and psychology, too, is no exception. That said, however, throughout the decades of the twentieth century, both the science and profession of psychology has blossomed into a science with a strong empirical basis. Researchers in the field are expected to uphold rigorous ethical and scientific standards when designing studies and performing research.

But part of the confusion occurs, perhaps, when studying human beings. Unlike the hard sciences of chemistry, physics and biology, the social and behavioral sciences—sociology, anthropology and psychology—are working with human beings and their environment and many variables converge. These “soft” sciences do not have the convenience of reducing their subjects to isolated islands of phenomena, the way chemists study chemical bonds or astrologists observe the movements of planets.

Human beings are complex.

And behaviorist attempts to reduce all human behavior to cause-and-effect mechanisms has largely been discredited in recent decades. Recent insights about the human brain and how it functions have been providing a wealth of knowledge for psychologists that are just beginning to find applications. Like their hard science counterparts, psychologists observe phenomena, make predictions, test ideas and, among other things, measure results. Mental health professions and clinicians then find real-world applications for this knowledge.

Psychology is a science.