If one is a psychologist or even has a passing interest in the field, one has likely encountered the question about whether psychology is truly a science or not. The debate has been prominent since psychology’s inception in the second half of the 19th century, and is evident in comments like that by William James who referred to it as “that nasty little subject." Scholars of the field know this debate has continued on and off, right up through the present day. The debate flared in the blogosphere a couple of years ago, after an op-ed piece by a microbiologist in the LA Times declared definitively that psychology was not a science, followed by several pieces in Psychology Today and Scientific American declaring definitively that psychology is, in fact, a science. Just last month, a long time scholar of the field authored the paper, Why Psychology Cannot Be an Empirical Science, and once again the blogosphere was debating the issue.

So what is the right answer? Is psychology a science or not? The answer is that it is complicated and the reason is that both science and psychology are complex, multifaceted constructs. As such, binary, blanket “yes” or “no” answers to the question fail. The answer I offer is that yes, it is largely a science, but there are important ways that it fails to live up to this description. To get a handle on why this is the right answer, let’s start with the construct of science, because if we are going to talk about the ways in which psychology is or is not a science, we had better have an idea of what we mean by both of these confusing terms.

Defining Science and Its Key Elements

For clarity of communication, it is often a good idea to start with some basic definitions, so let’s start with some generally agreed-upon definitions of science from reputable organizations.

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.

Science refers to a system of acquiring knowledge [based on] observation and experimentation to describe and explain natural phenomena.

These are solid definitions, but we need to flesh them out a bit. I consider science to be made up of four elements: 1) the scientific mindset; 2) the scientific method; 3) the knowledge system of science and 4) science as a rhetorical label. The first three are fairly straightforward and the fourth is particularly relevant for this debate and debates like it (i.e., involving what does or does not get classified as a science). These elements are crucial to understanding the ways in which psychology is and is not a science.

The first point to make is that the scientific mindset involves a set of assumptions about causality and complexity and how an observer can know things about the way the world works (technically, this is called a scientific epistemology). When one is thinking scientifically, one assumes that the natural world is a closed system that follows cause-effect processes that are lawful and discoverable (i.e., that there is no interference). The scientific mindset also includes the following characteristics: emphasis on empirical evidence (i.e., data collection) to develop explanations; attitudes of to possible (natural) explanations and a skepticism about tradition, revelation and authority; an emphasis on objectivity (i.e., independent from the of the observer); an emphasis on logical coherence; and the belief that humans can build systems of knowledge that do, in fact, correspond to the way the world actually works.

Another defining feather of science is its reliance on systematic methods of data collection and critical analyses of the ideas of science. These are the methods that students learn about when they are introduced to “doing science," and include elements such as systematic observation, measurement and quantification, data gathering, hypothesis testing, controlled experimentation (where possible), and theory construction.

Source: Gregg Henriques

Although the scientific method is often touted as the sin qua non of science, it is not. Indeed, if science were solely a method, then it would not be all that valuable, a point that is sometimes lost on empiricists enamored with the scientific method. Thus, it is crucial to keep in mind that the scientific method is not an end unto itself, but rather is a means to an end. The ultimate desired product of the method is a cumulative body of knowledge that offers an approximate description of how the world works. In concrete terms, this refers to the body of peer-reviewed journals, textbooks, and academic courses and domains of inquiry. Ideally, the body of knowledge will have a center that is consensually agreed upon (e. ., the Periodic Table in chemistry) and peripheral domains that represent the edges of scientific inquiry and where one will find much debate, , and differences of the opinion.

A final element that is particularly relevant in this context is that the term science has much rhetorical value in our culture. If something falls under the heading “science” then it is justified in receiving respect in the knowledge that it offers. Indeed, it is the “justifiability” argument that is at play in many of the debates about whether psychology warrants the title. For example, Alex Bezerow’s op-ed piece on Why Psychology Isn’t a Science explicitly hits on this issue:

The dismissive attitude scientists have toward psychologists isn't rooted in snobbery; it's rooted in intellectual frustration. It's rooted in the failure of psychologists to acknowledge that they don't have the same claim on secular truth that the hard sciences do. It's rooted in the tired exasperation that scientists feel when non-scientists try to pretend they are scientists.

Thus for Bezerow, (real) scientists dismiss psychologists because they are rightfully defending their turf. In contrast, defenders of psychology as science have told haters to “shut up already” about psychology not being a science because, although messy, psychology clearly has the “chops” to warrant the term.

Defining Psychology as a Science

Let’s turn from defining science to defining psychology. In what follows, I will be referring to psychology as it is presented in the academy, such as in Psych 101 textbooks. I mention this because it is different than the psychology that many people have in mind when they hear the term, which is the professional they might go see to talk with about their personal problems (note, the profession and practice of psychology is a whole separate issue).

There can be little doubt that academic psychology values and aspires to be a science, views itself as a science and, in many ways, looks and acts like a science. For starters, virtually every definition of psychology from every major group of psychologists define the field as a science. In addition, academic psychologists have long adopted the scientific mindset when it comes to their subject matter and have long employed scientific methods. Indeed, the official birth of psychology (Wundt’s lab) was characterized by virtue of the fact that it employed the methods of science (i.e., systematic observation, measurement, hypothesis testing, etc.) to understanding human conscious experience. And to this day, training in academic psychology is largely defined by training in the scientific method, measurement and data gathering, research design, and advanced statistical techniques, such as structural equation modeling, meta-analyses, and hierarchical linear . Individuals get their PhD in academic psychology by conducting systematic research and, if they want a in the academy, they need to publish in peer reviewed journals and often need to have a program of (fundable) research. To see how much the identity of a scientist is emphasized, consider that a major psychological organization (APS) profiles its members, ending with the catch phrase “and I am a psychological scientist!” Indeed, mainstream academic psychologists are so focused on empirical data collection and research methods that I have accused them of being “methodological fundamentalists,” meaning that they often act as if the only questions that are worthy of in the field are reducible to empirical methods.

In sum, academic psychology looks like a scientific discipline and it has a home in the academy largely as a science, and psychologists very much behave like scientists and employ the scientific method to answer their questions. So, at this level, it seems like a pretty closed case. If something looks like a science and acts like a science, then it likely should be considered a science. But we are not quite done with the debate because the question remains: If all these things are true, then what is the problem? Why are there still so many skeptics? And why has psychology had such a long period of critics both inside and outside the discipline claiming that there is a “crisis” at the core of our field?

How Psychology Fails as a Science

From where I sit, the reasons for the skepticism are very clear. And it is NOT found in the methods nor the mindsets of psychologists, both of which are “scientific.” Nor is the primary problem found in the fact that what psychologists study can be very difficult to measure, nor is it because people are too complicated, nor because humans make choices, nor because it involves consciousness. Nor is it because psychology is a young science (note that this is a myth—there are many ‘real’ sciences that are much younger than psychology). These are all red herrings to the “Is psychology a science?” debate.

The reason many are rightfully skeptical about its status is found in the body of scientific knowledge—psychology has failed to produce a cumulative body of knowledge that has a clear conceptual core that is consensually agreed upon by mainstream psychological experts. The great scholar of the field, Paul Meehl, captured this perfectly when he proclaimed that the sad fact that in psychology:

theories rise and decline, come and go, more as a function of baffled boredom than anything else; and the enterprise shows a disturbing absence of that cumulative character that is so impressive in disciplines like astronomy, molecular biology and .

Another great scholar of the field, Kenneth Gergen, likened acquiring psychological knowledge to building castles in the sand; the information gained from our methods might be impressive, but it is temporary, contextual, and socially dependent, and will be washed away when new cultural tides come in. Even mainstream icons, like Daniel Gilbert, readily acknowledge the cumulative knowledge problem. In this clip, he comments that one of psychology's big problems is that new paradigms simply “throw the babies out with the bathwater” and he wonders whether psychology as we know it will even be around in 10 or 15 years.

In technical terms, I am claiming that the core problem with the field is that it is “pre-paradigmatic," which means that psychology completely lacks agreement from the experts about what it is and what it is about, what its foundational theories or even frameworks are, what its key findings are, and how it fits with the rest of the body of scientific knowledge. The fact that psychology has been around now for almost 150 years and remains pre-paradigmatic is undeniably a very serious threat to the field's status as a real science.

To understand what paradigmatic science looks like, study Isaac Newton. Newton created a paradigm for understanding matter in motion that stands as a pinnacle of real scientific achievement. He mapped the behavior of objects in motion onto a new mathematics (calculus). Of course, those who know science know that Newton’s ideas were overturned at the beginning of the 20th Century, and his single paradigm was replaced by two paradigms, quantum mechanics and general relativity. But physics remains paradigmatic in the sense that these two paradigms are pillars that mainstream physicists agree on as providing us knowledge about how the world actually works. Likewise, chemistry is paradigmatic in that it has the Periodic Table and the laws of molecular forces to describe how matter changes chemically. Biology has cell theory, natural selection, and genetics, which together give it a foundational paradigm to describe living matter. Moreover, these broad domains of inquiry create a broad consilient (i.e., coherent) network of explanation that gives us knowledge of energy, matter, and life that is clearly worthy of the term "scientific."

Now, let’s shift and focus on psychology. In deep contrast to the broad disciplines of physics, chemistry and biology, psychology has no consensually agreed upon definition. Its most common definition, ‘the science of mind and behavior’ carries with it a deep dualism that is fundamentally unresolved by the competing paradigms of behaviorism and cognitivism (among others). Likewise, the field of psychology is completely unclear as to whether it deals in animals in general, with some animals (e.g., social mammals) in particular, or with humans only. Pick up any textbook or skim any basic intro to the field and what you get is a summary of major, competing, incommensurate models/paradigms that spell out a mushy territory between biology and human society. In addition, the start of the field begins with a review of major approaches that all have merit, such as behaviorism, cognitivism, humanism, , evolutionary and cultural approaches (not to mention purely physiological or nonwestern approaches), all of which are different and competing angles on the subject matter, however that is defined.

When this paradigmatic mess is then combined with other problems people point out, such as how complicated animals/humans are, the problems of consciousness, the problems of human science that blend objective and subjective, the problems of the role of science in culture (and on and on), the confusion becomes overwhelming.

But we are not quite done because the problems of consensual knowledge grow ever deeper when we consider how psychology is currently structured. The combination of: (a) psychology being separated from by its scientific methods; (b) the failure of the major historical paradigms to achieve consensual clarity; and (c) the fact that many psychologists anxiously try to defend against claim they are not a real science by doubling down on data collection has given rise to a massive empiricism within psychology. That is, mainstream psychologists are almost obsessed with data and data collection. With few exceptions, for a psychologist to make a name for herself, she needs a program of research, a method of data collection, a way of scientifically through folk understanding via operationalization, measurement and data analysis to achieve evidence for one’s perspective.

Why is this a problem? Because the mainstream is confused about where exactly the deep scientific problem within the field lies. To understand where the problem is, it is helpful to reference the well-known DIKW knowledge hierarchy, which shows that data and information are the base levels, which are then organized into knowledge systems (and, hopefully, ultimately ).

Source: Gregg Henriques

What mainstream psychologists generally fail to realize is that the fundamental problem of psychology exists at the level of Knowledge and Wisdom, NOT at the levels of data and information. Unfortunately, the reward structures and existing justification systems are all about data gathering and information (i.e., the never-ending call for more research). Unfortunately, religiously following the scientific method per se does not yield knowledge. It only yields data and information. From the vantage point offered here, there is no shortage of data and information—we already have an abundance of data and information. And certainly, no study is going to resolve the problems. Instead, the problems exist and have existed for more than a century at the level of knowledge—we can't even define what our field is about. Thus, the reason psychology fails to be a science is because it fails as a coherent system of knowledge that maps the relevant portion of the world. To see this obvious fact, ask 10 different psychologists the portion of the world they are trying to map when they use the term psychology and you will get 10 different answers. If you can’t even define the territory, you can’t develop consensual knowledge about it.

The Bottom Line

Is psychology a science? Yes, in the sense that psychology was defined by the application of scientific method(s) and psychologists conduct valuable research and have developed some key insights into , , consciousness, and the human condition. But a key feature of real scientific knowledge is that there is a clear, consensual center that provides a foothold to describe how (portions of) the world actually work. And it is here that psychology falls down in ways that physics, chemistry and biology do not. And it is in that sense that psychology is not a real science.