Chapter 1: The Science of Psychology

Science and Psychology

Introduction to the Science of Psychology


There are things I think I know, things I think I might know, and things I know I don’t know. I have learned that it is important to be able to tell the difference. In this book, I am trying to share some of the most important things I think I know about psychology. What I mean by important is that I think you will find many of these things interesting and some helpful in contemplating human potential and living your life under your unique human conditions.

I don’t know you personally but I am going to try to communicate based on certain assumptions. My assumptions are usually inferences based on things I think I know. I think I know that you just completed reading this sentence. Another thing I think I know (but am not as certain of), is that you are a student (probably a freshman) at a two- or four-year college or university or someone interested in psychology. Accordingly, I will try to relate the material to college’s and life’s usual demands (e.g., passing objective and essay examinations; time management, problem-solving, health and weight control, etc.).

Mighty oaks from tiny acorns grow.

In their attempt to understand their world and the meaning of their existence, humans increasingly rely on the scientific method to understand nature. All sciences are interested in establishing cause and effect relationships that apply under natural conditions. Over the past 400 years, there have been enormous advances in the physical, chemical, and biological sciences. This has resulted in applied technologies that have transformed the planet and the human condition.

This book describes the results of application of the scientific method to understanding the behavior of individual animals including humans. As a science, psychology studies how genetics (i.e. heredity or nature) and the environment (i.e. experience or nurture) influence covert (i.e. thinking and feeling) and overt behavior. That is, psychology assumes that the same principles that apply to acorns and oaks apply to human beings. Exposure to sunlight, water, and fertilizer determine the development of acorns. Throughout subsequent chapters we will see how different environmental variables influence human development. Traditionally, psychology has been broken down and introductory textbooks organized according to distinct content areas. In this book, these content areas are separated into those heavily influenced by genetics (biological psychology, sensation, motivation); those heavily influenced by experience (learning and cognition); and those emphasizing nature/nurture interactions (lifespan development, personality, social psychology, and maladaptive behavior). As will be observed as you advance through these content areas, the scientific method has been successfully applied to complex and important behavioral phenomena. Just as with other sciences, the establishment of cause and effect relationships has enabled the development of applied strategies.

The idea of potential is a paradox. It implies absolute limits and enormous possibilities. It is simultaneously pessimistic and optimistic. Potential can result in good or harm, creation or destruction. To consider psychology the science of human potential requires recognizing and accepting these contradictions. Every acorn has the potential to become a mighty oak but not every acorn will achieve that potential. Every healthy human child has enormous potential but not every child will achieve their potential.

The first paragraph of the serenity prayer, usually attributed to Reinhold Niebuhr, states:

God grant me the serenity
To accept the things I cannot change;
Courage to change the things I can;
And wisdom to know the difference.

The college experience can be described as encouraging students to consider the meaning of their lives within the context of lives that have been lived and lives that could be lived. This requires knowledge of history and culture to inform one regarding the likelihood of accomplishing change and imagination to consider other possibilities. The hope is that such knowledge and imagination will be applied wisely throughout one’s life.

An amusing distinction related to the serenity prayer describes three types of individuals: those that make it happen (i.e. demonstrate courage), those that watch it happen (i.e. are passive), and those that ask “what happened” (i.e. are clueless). The messages conveyed by the serenity prayer and this distinction relate to human potential. Those that are informed and active in considering options and making decisions are more likely to achieve their potential than those less informed or passive.

The Importance of Grades and Performance Standards

Do you think people have traits? Do you think some students are industrious and others are lazy? We will discuss such issues in Chapter 9 (Personality). I think I know that if you are a college student, you care about the grades you receive on exams. It is very difficult to be accepted into a college if you did not do reasonably well on exams. It is unlikely that you would have done well on exams if you didn’t care how you performed. Similarly, you will not excel at anything in life unless you are motivated to meet acceptable standards of performance. Parents and teachers probably tried hard when you were young to get you to care about how you performed in and out of school. We know that with respect to school grades, this often happens early. The reason we know is that research has demonstrated that some Head Start (Edlund, 1972), first-grade, and second-grade students (Clingman & Fowler, 1976) do better on IQ tests if they are given extrinsic rewards (e.g., candy or trinkets) for correct answers . Other students perform to the best of their ability without the extrinsic rewards. We will discuss such issues in Chapter 4 (Motivation & Emotion). Getting students to care about how they performed was obviously very important. Do you think research conducted with rats and pigeons can help us develop procedures to get children to care about their performance in school and on other tasks? We will review related questions later in this chapter and examine some of the practical implications of animal research in Chapter 5 (Direct Learning).

Edlund, and Clingman and Fowler are the first researchers cited in this book. Many more will follow. Complete references are listed alphabetically at the end of the book. You are encouraged to consult the original references whenever you have questions concerning a particular finding or conclusion or wish to obtain additional information. We live in a world where we are continually exposed to information designed to influence our beliefs and opinions. One of the most important skills you can acquire as a college student or in life is the ability to determine what constitutes a credible basis for believing something is true.

The Importance of Knowing When You Know and When You Don’t Know

Even experienced college students and adults sometimes have difficulty determining when they understand something and when additional (or more likely, different) preparation is required. One of the ways in which I will try to help you determine whether you understand material is by inserting essay questions at the end of major sections. Some of these questions can be answered through memorization. Others will require a level of understanding beyond memorization. They will require integrating key concepts and applying them so that you will appreciate the basis for our current understanding of psychological issues. Test yourself by writing out your answers to these questions. I suspect you will sometimes find that even though you thought you understood the material after you read it, you have difficulty providing a clear, complete, and accurate answer. If this is the case, you will know that it is necessary to review the material until you are able to provide such an answer. For example, can you answer the following question?


What is a good strategy for determining whether you understand the material in this textbook?

Take some time to write your answer and try to give yourself a grade. It is very important in life, not just in school, that you be able to objectively evaluate yourself and take steps to improve if you think you can do better. The reason I am giving you many essay problems to solve is that I think this will improve your ability to answer different essay questions in the future. The reason I believe this is true is because research results demonstrated that subjects improved their performance on a type of problem after being given many different examples of the same type of problem (Harlow, 1949). We will discuss this research when we get to Chapter 7 (Cognition and Intelligence).

As a youngster I participated in team sports and continue to be a fan. Sports can serve as a metaphor for much of the human condition, including school. In order to succeed, one requires natural ability as well as the motivation to perform at one’s best. We mentioned the importance of motivation to getting good grades in school. The role of inherited characteristics in determining your potential abilities will be treated in Chapter 2 (Biological Psychology).

If you were admitted to college or given a job, you were assumed to have the ability to succeed. It has been my experience as a college professor teaching freshmen through seniors (and graduate students) that this is almost always true of my students. Failure to perform to one’s capabilities can occur for a variety of reasons. Some students have family and/or financial responsibilities which prevent them from dedicating sufficient time to their studies. Others have not developed effective time management or study habits. No matter what the sport, playing up to your ability requires playing hard and playing smart. Some times in trying to hit a baseball it looks the size of a grapefruit and sometimes it appears the size of a golf ball. In shooting a basketball, sometimes the rim looks gigantic and other times it looks as though the ball can’t fit. No matter what type of day it is for you as an athlete, it is possible for you to hustle and play smart. In school, that means dedicating sufficient time and effective effort to your studying.

The Structure of College and Types of Knowing
Psychology is an academic discipline (i.e., body of knowledge based upon accepted, standardized methods). Before we consider the structure of the psychology curriculum and how it relates to the organization and content of this book, we will consider where psychology fits within the usual college curriculum. College students are asked (sometimes required) to take courses in many academic disciplines. Many of these courses are taught by departments housed in administrative units known as Arts and Sciences. Psychology is almost always housed within colleges of Arts and Sciences encompassing many disciplines not designed to prepare students for specific career paths (e.g., Art & Music, History, Philosophy, Physics, etc.). This is in contrast to pre-professional academic units such as Education, Business, and Nursing.

The undergraduate psychology major prepares students for graduate education and psychology related vocations such as clinical, counseling, school, and industrial psychology. The American Psychological Association website includes a substantial amount of information concerning career opportunities in psychology ( Another very helpful psychology career website is: to the Bureau of Labor Statistics the job growth for psychology till 2026 is projected to be faster than the average for other occupations.  See the following video for information concerning career opportunities in psychology.



Watch the following video for information regarding career opportunities with a psychology degree:

Over the years, many students have asked me why they have to spend so much of their first two years taking courses in Arts and Sciences (often referred to as core courses). They indicate the desire to just take courses in their favorite department (often referred to as a major). I often respond to such questions by referring to the famous picture based on the poem, The Blind Men and the Elephant (Saxe, 1872).

Figure 1.1  Blind men and an elephant


Often students are asked to take courses in the arts (e.g., history, literature, art or music, philosophy), “natural” (i.e., perhaps more accurately referred to as “laboratory”), and social and behavioral sciences. , which may be defined as the scientific study of individual thought, feeling, and behavior, is usually included in the last category with disciplines such as Sociology and Political Science. It is usually not included in the next-to-last category with disciplines such as Biology, Chemistry, and Physics even though, as we shall see, much of its research is conducted in laboratories. The arts, natural sciences, and behavioral sciences may be considered blind men with the elephant representing the human condition. Each perspective is attempting to help you place your life within a broader context of time, place, and ideas. History attempts to base its understanding on artifacts obtained over different time periods. Literature attempts to capture the essence of the human condition in different types of creative narratives (e.g., novels, plays, poems). Art and music provide different types of examples of human creativity. Philosophy applies reason and logic to questions regarding the meaning of life. Sometimes students believe since they have already taken similar courses in high school they will be repeating the same material. We have long known from the cognition literature (see Chapter 7) that repetition improves memory (Ebbinghaus, 1885). Also, you will probably find that your college professors ask you to do more and provide more difficult assignments, even when treating the same material.


Describe the structure of most colleges. Define psychology and describe where it fits within this structure?
Psychology and the Structure of this Book

The American Psychological Association guidelines for the psychology major do not recommend a specific combination of courses to achieve the learning goals. In fact, there are only three courses which are taken by practically all psychology majors: Introduction to Psychology, Psychological Statistics, and Research Methods. The Introduction to Psychology course is expected to provide a survey of the major content areas and theoretical perspectives including coverage of classic and contemporary research findings. Complicating the design of the Introduction to psychology course (and textbooks) is the fact that most students are not, and will never become psychology majors.

For decades, there has been consensus regarding the organization and content of introduction to psychology texts. They are typically divided in half, the first chapters often described as “psychology as a natural science” and the second group as “psychology as a social science.” Biological psychology, sensation and perception, motivation and emotion, learning, and cognition are examples of the former. Developmental psychology, personality, abnormal psychology, and social psychology are examples of the latter. Another way of distinguishing between the two types of chapters is to consider the first group as consisting of basic processes and the second group as chapters integrating these processes in a holistic manner. I have organized this book into three sections: content areas which may be described as “mostly nature” (biological psychology, sensation and perception, motivation and emotion); “mostly nurture” (direct learning, indirect learning (observational learning and language), cognition; and “nature/nurture” (developmental psychology, personality, abnormal psychology, social psychology). The “mostly nature” chapters describe how human structure relates to our physiological needs and sensory, motor, and nervous systems. The “mostly nurture” chapters review the role of experience in enabling humans to adapt to and transform their environmental circumstances. The “nature/nurture” section describes how these processes are integrated in the development of individual personality and social relations. Before we begin our discussion of the major content areas of psychology, we will review its early history.

Early History of Psychology

Wilhelm Wundt is given credit for founding the discipline of psychology at the German University of Leipzig in 1879. It is there and then that the first laboratory exclusively dedicated to psychological phenomena was established. Prior to then, research that would be considered psychological in nature was conducted in physics and neurology laboratories. Examples would include Fechner’s (1860) psychophysics research investigating just noticeable differences on sensory dimensions and Helmholtz’s studies of vision conducted in the 1850s and 1860s (translated into English in 1924).

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Figure 1.2 Wilhelm Wundt

Wundt (1873, 1896) defined psychology as the scientific study of conscious experience or, as some prefer, the study of the mind. His thinking was influenced by the chemist Dmitri Mendeleev, who formulated the periodic chart of elements. Wundt felt the goal of psychology should be to determine the fundamental elements of conscious experience, a sort of “mental chemistry.” His research suggested that the basic elements were images, sensations, and affective states (i.e., emotions) and that these had the attributes of quality, intensity, and duration. Wundt relied upon (i.e., looking inward) as the exclusive methodology. He felt that, with extensive training, individuals could be taught to make objective judgments regarding the attributes of what they were covertly (i.e., privately) experiencing. Thus, a subject might be placed in front of a desk and asked to describe the intensity and duration of her/his images, sensations, and emotional experiences.

Inevitably, other scientists interested in psychology reacted to different aspects of Wundt’s original approach to the discipline. In 1890, Harvard’s William James published his classic textbook The Principles of Psychology introducing much of the content and organization of subsequent introductory psychology textbooks. Edward Titchner, a student of Wundt’s who established a laboratory at Cornell University, made distinctions between Wundt’s and James’ approaches to psychology, labeling the former as and the latter as (1898, 1899). The University of Chicago’s James Angell responded (1903, 1907) with the functionalist perspective on the same distinction. This perspective was influenced by Charles Darwin’s (1859) contributions regarding natural selection. Titchner and Angell argued that Wundt’s original goal of analyzing conscious experience did not adequately emphasize the adaptive role played by the mind in survival. The major functionalists, in addition to William James and James Angell, included John Dewey and Harvey Carr of the University of Chicago. In addition to arguing for broadening the goals of psychology, they proposed expanding the methodology beyond introspection to include active experimentation in which the effects of different variables could be investigated.

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Figure 1.3  William James

In 1910, Max Wertheimer, a doctorate in psychology, was studying the perceptual experience of apparent movement later labeled as the . He had purchased a toy stroboscope that subjectively produced the impression of continuity from appropriately timed presentations of still photos (similar to projection of filmed still images in a movie theater) and was searching for subjects to investigate the effect. A friend provided laboratory facilities at the Frankfurt Psychological Institute and introduced him to Kurt Koffka and Wolfgang Kohler, two outstanding post-doctoral students to serve as subject colleagues (Kendler, 1987). This union resulted in the formation of the distinct psychological perspective called (Kohler, 1929). The German word gestalt is usually translated as “organized whole” and the catchphrase “the whole is greater than the sum of its parts” succinctly summarizes the major message of this approach. Gestalt psychologists disagreed with structuralism’s goal of analyzing conscious experience. The phi phenomenon was used to exemplify this message. Analyzing the phenomenon into distinct presentations of single photos was inappropriate. They argued that to do so, misrepresented and actually destroyed the very essence of what we perceive. When describing conscious experience, one had to work at the level of complete organized units. For example, to describe a desk in terms of the visual and tactile sensations it produces, does not capture the meaningful whole we perceive.

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Figure 1.4  Max Wertheimer


Watch the following video for a demonstration of the phi phenomenon:

It has been quipped that sciences advance when one scientist stands on the shoulders of another and psychology advances when one psychologist stomps on the head of another. The originator of this comment could have had John Watson in mind. Watson was trained as a functionalist at the University of Chicago and upon graduation accepted an excellent position at Johns Hopkins, where he remained for 12 years. Publication of his Psychological Review article, “Psychology as the Behaviorist Views It” (1913), resulted in no less than a permanent transformation of the discipline. Unlike the functionalists and Gestalt psychologists, Watson considered Wundt’s approach to have been a false start. His manifesto called for a change in the definition, goals, and methods of psychology. Watson reasoned that if psychology were to be considered a natural science the subject matter had to meet the three criteria of being observable, testable, and replicable. Since conscious experience cannot be independently verified by any means, testable questions could not be formulated and results could not be replicated. Watson limited the subject matter of psychology to observable behavior and defined the discipline as the science of individual behavior. The scientific method would be applied to the goal of prediction and control of observable behavior.

Watson’s was particularly critical of introspection as a method of inquiry. Not only was introspection inherently subjective, making independently verifiable replication of results impossible, it was a that unnecessarily limited the discipline’s subject matter. A reactive procedure is one in which the observational procedure affects the results. Watson argued that the act of introspecting necessarily altered one’s conscious experience. That is, the research findings obtained while introspecting would only apply under circumstances where an individual is engaged in introspection. This is not ordinarily the case. Also, since only reliable verbal human beings could accurately describe their introspections, it was impossible to study abnormal populations, children, or other animals as subjects.

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Figure 1.5  John Watson

Psychology Today

Each of the major early schools contributed significantly to the way psychology is currently practiced. Working backward, it is recognized that our scientific observations are limited to observable behavior (Skinner, 1990). Indeed, just as in other sciences, psychology’s subject matter is expanded with the development of new instruments. Astronomy benefited from the invention of the telescope, biology from the microscope, and psychology from such innovations as the IQ test, personality tests, reaction timer, galvanic skin response (GSR), Skinner-box, electroencephalograph (EEG), magnetic resonance imaging (MRI), computerized recording of behavior, and so on.

Current psychology has profited from the wisdom of the Gestalt psychologists as well. Indeed, a hard lesson was learned when it was realized that many conclusions reached regarding human memory based on the study of nonsense syllables (e.g., GUX) did not apply to meaningful words and sentences. For example, it has been demonstrated that the individual letters in words are processed simultaneously rather than sequentially (Adelman, Marquis, and Sabatos-DeVito, 2010). This means the word is processed as a “Gestalt’ (organized whole), not separate letters.

Functionalism continues to be influential within psychology. Indeed, evolutionary psychology, an approach consistent with major themes of this book, has emerged recently as a unifying perspective for such distinct content areas as biological psychology, learning, and social psychology (Confer, Easton, Fleischman, Goetz, Lewis, and Buss, 2010).

By virtue of being first, Wilhelm Wundt was able to define, state the goals, and develop the methodology of psychology. We have seen that this advantage had its cost since it provided others the opportunity to make suggestions and offer criticisms, not always in a collegial manner. Still, the most important components of structuralism have been incorporated within current practice. The fact that Introduction to Psychology textbooks practically all include chapters on perception, learning, and cognition demonstrates continued interest in conscious experience. We do not directly observe people perceive, learn and think. These topics must be studied in an inferential manner based upon behavioral observations. That is, people behave as though they perceive, learn, and think.

Introspection continues as a methodology for acquiring data in the form of self-report with the inherent limitations of such data being recognized and studied in their own right. Wherever possible, confirmatory measures other than self-report are frequently obtained. For example, in studies designed to reduce cigarette smoking, subjects are often required to provide carbon dioxide measures in addition to cigarette per day self-reports.


Describe Wundt’s initial structuralist definition, goals, and methods for the science of psychology along with the reactions of the functionalist, Gestalt, and behavioral schools. Show how our contemporary approach to psychology reflects the contributions of the early schools.



Figure 1.1 “Blind men and an elephant” is in the Public Domain, CC0

Figure 1.2 “Wilhelm Wundt” is in the Public Domain, CC0

Figure 1.3 “William James” is in the Public Domain, CC0

Figure 1.4 “Max Wertheimer” is in the Public Domain, CC0

Figure 1.5 “John Watson” by Prakruthi Prasad is licensed under CC BY-SA-4.0




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Psychology by Jeffrey C. Levy is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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