Is Psychology a Science?

Psychology is a science because it employs systematic methods of observation, experimentation, and data analysis to understand and predict behavior and mental processes, grounded in empirical evidence and subjected to peer review.

Science uses an empirical approach. Empiricism (founded by John Locke) states that the only source of knowledge is our senses – e.g., sight, hearing, etc.

In psychology, empiricism refers to the belief that knowledge is derived from observable, measurable experiences and evidence, rather than from intuition or speculation.

This was in contrast to the existing view that knowledge could be gained solely through the powers of reason and logical argument (known as rationalism).  Thus, empiricism is the view that all knowledge is based on or may come from experience.

Through gaining knowledge through experience, the empirical approach quickly became scientific and greatly influenced the development of physics and chemistry in the 17th and 18th centuries.

empiricism psychology science

The idea that knowledge should be gained through experience, i.e., empirically, turned into a method of inquiry that used careful observation and experiments to gather facts and evidence.

The nature of scientific inquiry may be thought of at two levels:

1. That to do with theory and the foundation of hypotheses.

2. And actual empirical methods of inquiry (i.e. experiments, observations)

The prime empirical method of inquiry in science is the experiment.

The key features of the experiment are control over variables (independent, dependent, and extraneous), careful, objective measurement, and establishing cause and effect relationships.

Features of Science

Empirical Evidence

  • Refers to data being collected through direct observation or experiment.
  • Empirical evidence does not rely on argument or belief.
  • Instead, experiments and observations are carried out carefully and reported in detail so that other investigators can repeat and attempt to verify the work.

Objectivity

  • Researchers should remain value-free when studying; they should try to remain unbiased in their investigations. I.e., Researchers are not influenced by personal feelings and experiences.
  • Objectivity means that all sources of bias are minimized and that personal or subjective ideas are eliminated. The pursuit of science implies that the facts will speak for themselves, even if they differ from what the investigator hoped.

Control

  • All extraneous variables need to be controlled in order to be able to establish the cause (IV) and effect (DV).

Hypothesis testing

  • E.g., a statement made at the beginning of an investigation that serves as a prediction and is derived from a theory. There are different types of hypotheses (null and alternative), which need to be stated in a form that can be tested (i.e., operationalized and unambiguous).

Replication

  • This refers to whether a particular method and finding can be repeated with different/same people and/or on different occasions to see if the results are similar.
  • If a dramatic discovery is reported, but other scientists cannot replicate it, it will not be accepted.
  • If we get the same results repeatedly under the same conditions, we can be sure of their accuracy beyond a reasonable doubt.
  • This gives us confidence that the results are reliable and can be used to build up a body of knowledge or a theory: which is vital in establishing a scientific theory.

Predictability

  • We should aim to be able to predict future behavior from the findings of our research.
 

The Scientific Process

Before the twentieth century, science largely used induction principles – making discoveries about the world through accurate observations, and formulating theories based on the regularities observed.

Newton’s Laws are an example of this. He observed the behavior of physical objects (e.g., apples) and produced laws that made sense of what he observed.

The scientific process is now based on the hypothetico-deductive model proposed by Karl Popper (1935).  Popper suggested that theories/laws about the world should come first, and these should be used to generate expectations/hypotheses, which observations and experiments can falsify.

As Popper pointed out, falsification is the only way to be certain: ‘No amount of observations of white swans can allow the conclusion that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion.

Darwin’s theory of evolution is an example of this. He formulated a theory and tested its propositions by observing animals in nature.  He specifically sought to collect data to prove his theory / disprove it.

Thomas Kuhn argued that science does not evolve gradually towards truth, science has a paradigm that remains constant before going through a paradigm shift when current theories can’t explain some phenomenon, and someone proposes a new theory. Science tends to go through these shifts; therefore, psychology is not a science as it has no agreed paradigm.

There are many conflicting approaches, and the subject matter of Psychology is so diverse; therefore, researchers in different fields have little in common.

Psychology is really a very new science, with most advances happening over the past 150 years or so.  However, it can be traced back to ancient Greece, 400 – 500 years BC.  The emphasis was a philosophical one, with great thinkers such as Socrates influencing Plato, who in turn influenced Aristotle.

Plato argued that there was a clear distinction between body and soul, believed very strongly in the influence of individual differences on behavior, and played a key role in developing the notion of “mental health,” believing that the mind needed stimulation from the arts to keep it alive.

Aristotle firmly believed in the idea that the body strongly affected the mind – you might say he was an early biopsychologist.

Psychology as a science took a “back seat” until Descartes (1596 – 1650) wrote in the 17th century. He believed strongly in the concept of consciousness, maintaining that it was that that separated us from animals.

He did, however, believe that our bodies could influence our consciousness and that the beginnings of these interactions were in the pineal gland – we know now that this is probably NOT the case!

From this influential work came other important philosophies about psychology, including the work by Spinoza (1632 – 1677) and Leibnitz (1646 – 1716). But there still was no single, scientific, unified psychology as a separate discipline (you could certainly argue that there still isn’t”t!).

When asked, “Who is the parent of psychology?” many people answer, “Freud.” Whether this is the case or not is open to debate, but if we were to ask who the parent of experimental psychology is, few would likely respond similarly.  So, where did modern experimental psychology come from, and why?

Psychology took so long to emerge as a scientific discipline because it needed time to consolidate.  Understanding behavior, thoughts, and feelings are not easy, which may explain why it was largely ignored between ancient Greek times and the 16th century.

But tired of years of speculation, theory, and argument, and bearing in mind Aristotle’s plea for scientific investigation to support the theory, psychology as a scientific discipline began to emerge in the late 1800s.

Wilheim Wundt developed the first psychology lab in 1879.  Introspection was used, but systematically (i.e., methodologically). It was really a place from which to start thinking about how to employ scientific methods to investigate behavior.

The classic movement in psychology to adopt these strategies was the behaviorists, who were renowned for relying on controlled laboratory experiments and rejecting any unseen or subconscious forces as causes of behavior. 

And later, cognitive psychologists adopted this rigorous (i.e., careful), scientific, lab-based approach.

Psychological Approaches

Psychoanalysis has great explanatory power and understanding of behavior. Still, it has been accused of only explaining behavior after the event, not predicting what will happen in advance, and being unfalsifiable.

Some have argued that psychoanalysis has approached the status more of a religion than a science. Still, it is not alone in being accused of being unfalsifiable (evolutionary theory has, too – why is anything the way it is? Because it has evolved that way!), and like theories that are difficult to refute – the possibility exists that it is actually right.

Kline (1984) argues that psychoanalytic theory can be broken down into testable hypotheses and tested scientifically. For example, Scodel (1957) postulated that orally dependent men would prefer larger breasts (a positive correlation) but, in fact, found the opposite (a negative correlation).

Although Freudian theory could be used to explain this finding (through reaction formation – the subject showing exactly the opposite of their unconscious impulses!), Kline has nevertheless pointed out that no significant correlation would have refuted theory.

Behaviorism has parsimonious (i.e., economic / cost-cutting) theories of learning, using a few simple principles (reinforcement, behavior shaping, generalization, etc.) to explain a wide variety of behavior from language acquisition to moral development.

It advanced bold, precise, and refutable hypotheses (such as Thorndike’s law of effect) and possessed a hard core of central assumptions such as determinism from the environment (it was only when this assumption faced overwhelming criticism by the cognitive and ethological theorists that the behaviorist paradigm/model was overthrown).

Behaviorists firmly believed in the scientific principles of determinism and orderliness. They thus came up with fairly consistent predictions about when an animal was likely to respond (although they admitted that perfect prediction for any individual was impossible).

The behaviorists used their predictions to control the behavior of both animals (pigeons trained to detect life jackets) and humans (behavioral therapies), and indeed Skinner, in his book Walden Two (1948), described a society controlled according to behaviorist principles.

Cognitive psychology – adopts a scientific approach to unobservable mental processes by advancing precise models and conducting experiments on behavior to confirm or refute them.

Full understanding, prediction, and control in psychology are probably unobtainable due to the huge complexity of environmental, mental, and biological influences upon even the simplest behavior (i.e., all extraneous variables cannot be controlled).

You will see, therefore, that there is no easy answer to the question, “is psychology a science?”. But many approaches of psychology do meet the accepted requirements of the scientific method, whilst others appear to be more doubtful in this respect.

Alternatives

However, some psychologists argue that psychology should not be a science. There are alternatives to empiricism, such as rational research, argument, and belief.

The humanistic approach (another alternative) values private, subjective conscious experience and argues for the rejection of science.

The humanistic approach argues that objective reality is less important than a person’s subjective perception and subjective understanding of the world. Because of this, Carl Rogers and Maslow placed little value on scientific psychology, especially using the scientific laboratory to investigate human and other animal behavior.

A person’s subjective experience of the world is an important and influential factor in their behavior. Only by seeing the world from the individual’s point of view can we really understand why they act the way they do. This is what the humanistic approach aims to do.

Humanism is a psychological perspective that emphasizes the study of the whole person. Humanistic psychologists look at human behavior not only through the eyes of the observer but through the eyes of the person doing the behavior. Humanistic psychologists believe that an individual’s behavior is connected to his inner feelings and self-image.

The humanistic approach in psychology deliberately steps away from a scientific viewpoint, rejecting determinism in favor of free will, aiming to arrive at a unique and in-depth understanding. The humanistic approach does not have an orderly set of theories (although it does have some core assumptions).

It is not interested in predicting and controlling people’s behavior – the individuals themselves are the only ones who can and should do that.

Miller (1969), in “Psychology as a Means of Promoting Human Welfare,” criticizes the controlling view of psychology, suggesting that understanding should be the main goal of the subject as a science since he asks who will do the controlling and whose interests will be served by it?

Humanistic psychologists rejected a rigorous scientific approach to psychology because they saw it as dehumanizing and unable to capture the richness of conscious experience.

In many ways, the rejection of scientific psychology in the 1950s, 1960s, and 1970s was a backlash to the dominance of the behaviorist approach in North American psychology.

Common Sense Views of Behavior

In certain ways, everyone is a psychologist. This does not mean that everyone has been formally trained to study and be trained in psychology.  People have common sense views of the world, of other people, and of themselves. These common-sense views may come from personal experience, from our upbringing as a child, and through culture, etc.

People have common-sense views about the causes of their own and other people’s behavior, personality characteristics they and others possess, what other people should do, how to bring up your children, and many more aspects of psychology.

Informal psychologists acquire common-sense knowledge in a rather subjective (i.e., unreliable) and anecdotal way.  Common-sense views about people are rarely based on systematic (i.e., logical) evidence and are sometimes based on a single experience or observation.

Racial or religious prejudices may reflect what seems like common sense within a group of people. However, prejudicial beliefs rarely stand up to what is actually the case.

Common sense, then, is something that everybody uses in their day-to-day lives, guides decisions and influences how we interact with one another.

However, because it is not based on systematic evidence or derived from scientific inquiry, it may be misleading and lead to one group of people treating others unfairly and in a discriminatory way.

Limitations of Scientific Psychology

Despite having a scientific methodology worked out (we think), some further problems and arguments doubt psychology is ever a science.

Limitations may refer to the subject matter (e.g., overt behavior versus subjective, private experience), objectivity, generality, testability, ecological validity, ethical issues, and philosophical debates, etc.

Science assumes that there are laws of human behavior that apply to each person. Therefore, science takes both a deterministic and reductionist approach.

Science studies overt behavior because overt behavior is objectively observable and can be measured, allowing different psychologists to record behavior and agree on what has been observed. This means that evidence can be collected to test a theory about people.

Scientific laws are generalizable, but psychological explanations are often restricted to specific times and places. Because psychology studies (mostly) people, it studies (indirectly) the effects of social and cultural changes on behavior.

Psychology does not go on in a social vacuum. Behavior changes over time and in different situations. These factors, and individual differences, make research findings reliable for a limited time only.

Are traditional scientific methods appropriate for studying human behavior? When psychologists operationalize their IV, it is highly likely that this is reductionist, mechanistic, subjective, or just wrong.

Operationalizing variables refers to how you will define and measure a specific variable as it is used in your study. For example, a biopsychologist may operationalize stress as an increased heart rate. Still, it may be that in doing this, we are removed from the human experience of what we are studying. The same goes for causality.

Experiments are keen to establish that X causes Y, but taking this deterministic view means that we ignore extraneous variables and the fact that at a different time, in a different place, we probably would not be influenced by X. There are so many variables that influence human behavior that it is impossible to control them effectively. The issue of ecological validity ties in really nicely here.

Objectivity is impossible. It is a huge problem in psychology, as it involves humans studying humans, and it is very difficult to study people’s behavior in an unbiased fashion.

Moreover, in terms of a general philosophy of science, we find it hard to be objective because a theoretical standpoint influences us (Freud is a good example). The observer and the observed are members of the same species are this creates problems of reflectivity.

A behaviorist would never examine a phobia and think in terms of unconscious conflict as a cause, just like Freud would never explain it as a behavior acquired through operant conditioning.

This particular viewpoint that a scientist has is called a paradigm (Kuhn, 1970). Kuhn argues that most scientific disciplines have one predominant paradigm that the vast majority of scientists subscribe to.

Anything with several paradigms (e.g., models – theories) is a pre-science until it becomes more unified. With a myriad of paradigms within psychology, it is not the case that we have any universal laws of human behavior. Kuhn would most definitely argue that psychology is not a science.

Verification (i.e., proof) may be impossible. We can never truly prove a hypothesis; we may find results to support it until the end of time, but we will never be 100% confident that it is true.

It could be disproved at any moment. The main driving force behind this particular grumble is Karl Popper, the famous philosopher of science and advocator of falsificationism.

Take the famous Popperian example hypothesis: “All swans are white.” How do we know for sure that we will not see a black, green, or hot pink swan in the future? So even if there has never been a sighting of a non-white swan, we still haven’t really proven our hypothesis.

Popper argues that the best hypotheses are those which we can falsify – disprove. If we know something is not true, then we know something for sure.

Testability: much of the subject matter in psychology is unobservable (e.g., memory) and, therefore, cannot be accurately measured. The fact that there are so many variables that influence human behavior that it is impossible to control the variables effectively.

So, are we any closer to understanding a) what science is and b) if psychology is a science? Unlikely. There is no definitive philosophy of science and no flawless scientific methodology.

When people use the term “Scientific,” we all have a general schema of what they mean, but when we break it down in the way that we just have done, the picture is less certain. What is science? It depends on your philosophy. Is psychology a science? It depends on your definition. So – why bother, and how do we conclude all this?

Slife and Williams (1995) have tried to answer these two questions:

1) We must at least strive for scientific methods because we need a rigorous discipline. If we abandon our search for unified methods, we’ll lose a sense of what psychology is (if we knew it in the first place).

2) We need to keep trying to develop scientific methods that are suitable for studying human behavior – it may be that the methods adopted by the natural sciences are not appropriate for us.

Further Information

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Olivia Guy-Evans, MSc

BSc (Hons) Psychology, MSc Psychology of Education

Associate Editor for Simply Psychology

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.


Saul Mcleod, PhD

Educator, Researcher

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul Mcleod, Ph.D., is a qualified psychology teacher with over 18 years experience of working in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

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