Module 1
The Science of Psychology

The subject matter of psychology has existed as a body of knowledge at least as long, or longer, than any other, but psychology itself is one of the youngest of the sciences. People have always known something of what they were doing and how they felt, and speculated about the reasons for their behavior and emotions. They knew that some types of exercise are very tiring; that one person is a better leader than another, and that some people work harder than others. But such commonplace knowledge does not result from, or satisfy the requirements of, scientific inquiry into the nature and causes of the phenomena observed. It is not enough to say that exercise is less tiring if it is interesting, a person is a good leader because he has charisma, or that people who work harder are better motivated. These types of generalizations contribute little in efforts to design mot e productive work environments, to select and train more effective leaders, or to help individuals redirect their efforts in ways that enable them to achieve their own personal goals. Psychology began to be a science when serious researchers started developing precise ways of measuring psychological phenomena and from that, observing functional relationships.

The science of psychology is dedicated to the triple task of refining, explaining and using its subject matter (e.g., the knowledge of behavior and emotions) to achieve known objectives. That is:


In psychology the word "behavior" has implications far beyond those normally associated with the term

The basic raw material, or the events, with which a psychologist works is human and animal behavior, just as other scientists study the behavior of planets or electrons. Perhaps because the science of psychology is so young, there are still many different views as to what behavior should be observed, and how it should be interpreted and modified. One of your objectives in this course is to learn to make a well-informed evaluation of the arguments. But whatever theories are proposed to explain the observations, it is some type of behavior that is being observed. There are many types of behavior and many methods of observation. Also, different psychologists might use their observations to support conclusions about different human conditions, e.g., innate or hereditary qualities, emotions, attitudes, or even the motivating influence of the environ ment within which the behavior occurs. Still, observation of these other conditions is at best imperfect; to some extent their nature, and even their existence, must be inferred from some observation of behavior. To this extent, the entire field of psychology can be defined as "The Science of Human and Animal Behavior."


If the subject matter of psychology has been known and widely discussed for so many millennia, why was the science of psychology so slow to develop? The behavior of organisms (human or animal) is certainly complex, but so is the behavior of an economic system. It takes training, and sometimes special equipment, to make precise and accurate observations of behavior. But neither the skills nor the equipment are more sophisticated than those required by a physicist or biochemist. Perhaps part of the reason has been that the world is full of psychologists, often naive and ill informed, to be sure, but psychologists nevertheless. Every day, each of us does, intuitively at least, some of the things psychologists do systematically. We observe behavior in ourselves and others, make judgments about cause and effect, predict more or less accurately what behavior will occur in the future, and make attempts (however fumbling) to bring about modifications in behavior. Also, since we are all successful in these efforts, at least sometimes, we can all claim some degree of expertise. Since we already have answers that satisfy most of our personal needs, we have little or no need to ask questions, and no true science can develop except through rigorous and disciplined inquiry.

Wrong answers that make sense may delay the research needed to find correct answers.

Unfortunately, naive explanations of behavior are usually ambiguous and often contradictory. Try to reconcile such old saws as "absence makes the heart grow fonder" with "out of sight, out of mind." This does not mean that naive explanations are bad; on the contrary, they are often useful in helping us in our dealings with other people. But one should realize that there is often a considerable difference between the common-sense analysis of behavior and the scientific one. Aristotle reached the very sensible conclusion that a heavy object falls to the ground faster than a lighter one. It was not until 2000 years later that someone (Galileo) tested, experimentally, the validity of Aristotle's assertion. He dropped objects of different weights and made precise observa tions of the time each one took to reach the ground. At any time during that 2000 years someone could have performed a similar experiment and discovered that weight has no effect on the rate of fall. Aristotle's explanation made sense, but Galileo was studying acceleration and developing a technology of ballistics; and the accepted explanation did not fit.

Introspective data are useful as long as one takes into consideration their limitations. An argument may appear logical, without being meaningful

The common-sense analysis of the behavior of bodies in a free fall provided an acceptable answer to the questions that people asked for 2000 years, just as "charisma" or "drive" or "forceful personality" were acceptable ways of explaining effective leadership. The common-sense answers are no longer adequate; we are now asking the questions and making the types of observations required to build a body of scientific knowledge about ourselves, the way we behave, and why. But how can we acquire a scientific understanding of human behavior? One method is just to ask someone about his behavior: "Why did you do that?" or "What do you mean by that?" or "How do you feel when that happens?" Information obtained from this type of investigation is called introspective data. In introspection, a person "looks inside" and reports on his inner states and emotions. Certainly, psychologists are interested in "what goes on in people's heads," and early research tended to be based on analyses of introspective data which were readily available in large quantities; we all enjoy talking about how we feel.

Psychologists recognize, however, that such data have a severe limitation; that is, they reflect private events, and are therefore difficult to verify objectively. No one can be sure that one person's inner perceptions are the same as another's, even though they may go by the same name. If we want to build a science of psychology only for Joe Smith, we want to know as much as possible about Joe Smith's inner states. But if we want to build a science which has some validity for everyone, we must seek evidence that is far more objective and public.

We often hear references to inner perceptions advanced as evidence in support of an assertion. The following dialogue illustrates a way in which private and unverifiable events are often introduced as evidence.

A. What did you say?
B. I said the room is crawling with little green dragons.
A. Where are they? I can't see anything like that.
B. That's what is really far out about them; they're invisible little green dragons.
A. But I can't feel them or hear them either.
B. See, you are just beginning to realize the uniqueness of this occurrence. We are on the edge of the unknown and we must discard our prejudices. These creatures are not only invisible but inaudible and intangible as well; it is this that makes them really fantastic. (B is now counting his losses as gains, the final stage of unscientific argument. He has happily pushed himself out on a limb and sawn himself off and now is likely to appeal to some magical spell to keep from falling.)
A. They certainly are remarkable; but what makes you think they exist?
B. I have been favored with Direct Awareness. I'm one of the rare ones.

This kind of answer falls in the category of subjective evidence; it is evidence which not only cannot be verified in public, it has been stated in a way that rules out any possibility of ever being related to any direct observation.

Sometimes the last stages of this type of argument proceed with A suggesting that B has now made it clear that he is using the normally meaningful phrase "little green dragons" in an entirely meaningless way. Thus B may deny indignantly, saying that he knows what he means by the phrase. But it is not good enough for B to believe he is right, or even to present a logical argument (which he failed to do anyway). B has to prove that he is using the term meaningfully, by giving the kind of evidence that he thinks supports it. People can be mistaken in thinking they know what they mean by a term, just as they can be mistaken in thinking they have reliable intuition, direct revelation, and so on. Popular literature is full of misconceptions that have an aura of scientific validity because they are explained in unfamiliar, or sophisticated terminology. But even scientific terms are useless in supporting a conclusion unless they are used in a scientifically meaningful way. The psychologist wants more than pronouncements of knowledge; he expects the evidence.


The early definition of behavior had to be expanded to serve the needs of scientific inquiry

John B. Watson, in 1913, was one of the first to proclaim that behavior was the proper data for psychology. He took the position that behavior refers only to public events and ruled out any events which could not be observed directly. Watson wrote, "The time seems to have come when psychology must discard all references to consciousness, when it need no longer delude itself into thinking that it is making mental states the object of observation." This extreme position has been modified by psychologists since then, but Watson had enough evidence for his conclusions to ensure that they could not be ignored entirely. His basic principles have led to the development of many useful analytical techniques. For example, psychologists often classify behaviors into two categories: overt and covert. Overt behaviors are those which are directly observable, such as talking, running, scratching or blinking. Covert behaviors are those which go on inside the skin. They include such private events as thinking and imagining. Some covert behaviors are only detectable by the person who is performing them, in which case they are truly private, whereas others may be detected by special means.

Overt behaviors have many observable properties, such as form, intensity, duration, and frequency. Such properties can be perceived by our unaided are always public senses, measured and classified. Covert behaviors, on the other hand, can only be detected by inference or through the use of special techniques and devices. For example, some covert behaviors can be made public by the use of sensitive instruments that pick up minute electrical impulses from the internal workings of the body. A heart beat, normally a private event, can be heard and amplified for many people to hear simultaneously. Using such instruments, it has been shown that the heart rate increases when a person feels anxious, and muscular activity has been detected in the vocal cords when a person is thinking to himself. It has been found that public and private behaviors are often correlated. When a person reports that he is feeling tense, a scientist can often detect impulses from various muscle groups which indicate a state of tension. Even some components of the usually very private event of dreaming can be detected in the measurement of brain waves and in the movement of the eyeballs during sleep.

Covert behaviors may be private or public

There are other covert behaviors such as imagining, perceiving, and dreaming, which no instrumentation has yet been able to detect. Psychologists are by no means unanimous as to the place of such private events in the science of psychology. Some take an extreme viewpoint similar to Watson's that only detectable behaviors which are public, and therefore open to observa- tion by unbiased observers, are proper. But to most psychologists, private events are as much a part of the real world as their more easily observable counterparts. Thus, most psychologists do accept private covert behaviors as an important factor in research and therapy, but with full recognition that they may be less reliable, and that special methodological care must be taken in using such events as data. Watson's position had to be modified, but he prompted psychologists to think about behavior in ways that made it essential to the study of psychology.


One reason students take introductory psychology is to find answers to cer tain personal questions. For example: what makes people do the strange things they do? Perhaps you are interested in such questions as the latest teaching methods, attracting members of the opposite sex, or maintaining stable friendships. In this course, you will learn to find your own answers to many of these types of questions. But remember that some of the simplest questions one can ask in psychology are the hardest to answer. If you want to know what causes a particular characteristic of your own, you are asking a question that may be as hard to answer as a corresponding question about the causes of cancer. It may also be a question to which you could get three entirely different answers from three equally well-qualified psychologists.

Now that you have read the narrative text portion of this module, take the

Progress Check 1

When you have answered all the questions, grade it yourself from the answer key.