WHAT IS PSYCHOLOGY?
Psychology is not confined to investigating abnormal behavior, as many people mistakenly assume. Psychology is the scientific study of behavior and mental processes in all their many facets. As such, viewed from a wealth of different perspectives, it encompasses every aspect of human thoughts, feelings, and actions.
The Breadth of Psychology
One way to grasp the breadth and depth of topics in psychology is to look at the major subfields within it. Psychology is not so much a single, unified field of study as it is an umbrella concept for a loose amalgamation of different subfields.
Developmental Psychology
Developmental psychologists study all aspects of human growth and change - physical, mental, social, and emotional - from the prenatal period through old age. Most specialize in a particular stage of human development. Child psychologists focus on infants and children, concerning themselves with such issues as whether babies are born with distinct temperaments and at what age sex differences in behavior emerge. Adolescent psychologists look largely at how puberty affects a range of developmental phenomena, from relationships with peers and parents to the search for a personal identity. Finally, life-span psychologists focus on the challenges and changes of adulthood, from marrying and having children to facing the transitions related to aging and eventual death.
Physiological Psychology
Physiological psychologists investigate the biological basis of human behavior, thoughts, and emotions. Among these, neuropsychologists are interested in the workings of the brain and nervous system. Their colleagues known as biological psychologists study the body's biochemistry and the ways that hormones, psychoactive medications, and "social drugs" affect us. Behavioral geneticists add yet another dimension: They explore the impact of heredity on both normal and abnormal behavior.
Experimental Psychology
Experimental psychologists conduct research on basic psychological processes, including learning, memory, sensation, perception, thinking, motivation, and emotion.
Personality Psychology
Personality psychologists study the differences among individuals in such traits as sociability, conscientiousness, emotional stability, self-esteem, agreeableness, aggressive inclinations, and openness to new experiences.
Clinical and Counseling Psychology
When asked to describe a psychologist, most people think of a therapist who sees troubled people in an office, clinic, or hospital. This popular view is half correct. About 50% of psychologists specialize in clinical or counseling psychology, both of which seek to help people deal more successfully with their lives. Clinical psychologists are interested primarily in the diagnosis, causes, and treatment of psychological disorders, such as depression or acute anxiety. Counseling psychologists, in contrast, are concerned mainly with the everyday problems with adjustment that most of us face at some point in life, such as making a difficult career choice or coping with a troubled relationship. Clinical and counseling psychologists often divide their time between treating people and conducting research on the causes of psychological disorders and the effectiveness of different types of therapy.
Social Psychology
Social psychologists believe that our thoughts, feelings, and behaviors are all greatly influenced by other people and the social situations in which we find ourselves. Social psychology is the scientific study of how these social influences are exerted and the effects they have.
Industrial and Organizational (I/O) Psychology
Industrial and organizational (I/O) psychologists apply the principles of psychology to the workplace. They are concerned with such practical issues as selecting and training personnel and improving productivity and working conditions.
Enduring Issues
What do psychologists who study organizations, psychological disorders, memory and cognition, behavioral genetics, or changes across the life span have in common? All psychologists share a common interest in five enduring issues that override their areas of specialization and cut to the core of what it means to be human.
Person-Situation
To what extent is behavior caused by such internal processes as thoughts, emotions, motives, attitudes, values, personality, and genes? In contrast, to what extent is behavior caused by such external factors as incentives, environmental cues, and the presence of other people? Put another way, are we masters of our fate or victims of circumstances? We will encounter these questions most directly in our consideration of behavior genetics, learning, emotion and motivation, personality, and social psychology.
Nature-Nurture
To what extent are we a product of innate, inborn tendencies, and to what extent are we a reflection of experiences and upbringing? This is the famous "nature versus nurture" debate. For decades, psychologists have argued about the relative influence of heredity (genes) versus environment (experience) on thought and behavior. More recently, psychologists have begun studying the extent to which genetic differences only appear in specific environments, and the extent to which certain experiences only affect people with particular genetic predispositions (Champagne, 2009). This complex issue surfaces most clearly in our discussions of behavior genetics, intelligence, development, personality, and abnormal psychology.
Stability-Change
Are the characteristics we develop in childhood more or less permanent and fixed, or do we change significantly over the course of our lives? Developmental psychologists are especially interested in these and other questions, as are psychologists who specialize in personality, adjustment, abnormal psychology, and therapy.
Diversity-Universality
Because we are all human, each person is like every other person. But in some respects, each of us is like no other person. Thus, anywhere humans exist there will be both similarity and diversity. Throughout this book, we will encounter these questions: Does our understanding of human behavior apply equally well to every human being? Does it apply only to men or just to women, or only to particular racial or ethnic groups or particular societies (especially our own)? Do we perhaps need "different psychologies" to account for the wide diversity of human behaviors (Arnett, 2008)?
Mind-Body
Finally, how are mind and body connected? Many psychologists are fascinated by the relationship between what we experience (such as thoughts and feelings) and what are biological processes are (such as activity in the nervous system). This mind-body issue will arise most clearly in our discussions of the biological basis of behavior, sensation and perception, altered states of consciousness, emotion and motivation, adjustment and health psychology, and disorders and therapy.
These five issues represent enduring themes in the history of psychology. Depending on the events and intellectual climate of a given time period, one or another of these issues has assumed special prominence in the history of psychology. For example, at the beginning of the 21st century the role of genetics (heredity) is receiving much greater attention than in the past. Diversity is also an issue of much greater concern, as is the role of biological processes.
Psychology as Science
Psychologists rely on the scientific method when seeking to answer questions. They collect data through careful, systematic observation; attempt to explain what they have observed by developing theories; make new predictions based on those theories; and then systematically test those predictions through additional observations and experiments to determine whether they are correct. Thus, like all scientists, psychologists use the scientific method to describe, understand, predict, and, eventually, achieve some measure of control over what they study.
For example, consider the question of whether males are more aggressive than females. How would psychologists approach the issue? First, they would want to find out whether in fact men and women actually differ in aggressive behavior. Hundreds of research studies have addressed this question, and the evidence seems conclusive: Although males and females do not differ significantly in feelings of anger, males are more physically and verbally aggressive than females (Archer, 2009). Males are usually more physically aggressive than females in nonhuman species as well. Once psychologists have established that there are indeed sex differences in aggression, the next step is to explain those differences. A number of explanations are possible. For example, if you are a physiological psychologist, you will probably ascribe these differences to genetics or body chemistry. If you are a social psychologists, you might explain the differences in terms of cultural norms, which require males to "stand up for themselves" and hold that physical aggression isn't "feminine." If you are an evolutionary psychologist, you might point out that females of many species (especially mammals) have traditionally born greater responsibility than males for caring for their offspring and ensuring their survival. Perhaps females have evolved to avoid hostile confrontations that could harm or kill them.
Each of these explanations stands as a theory about the causes of sex differences in aggression. And each theory allows you to make new hypotheses, or predictions, about the phenomenon in question. For example, if gender differences in aggression arise because males have higher levels of testosterone than females do, you would predict that extremely violent men should have higher levels of testosterone than do men who are generally nonviolent. If sex differences in aggression reflect cultural norms, you would predict that within societies that encourage nonviolence and peaceful coexistence the difference in aggression across the sexes should be small. If sex differences are due to an evolutionary advantage for females to avoid direct, aggressive confrontations in order to reproduce and care for their offspring, you would expect sex differences to be greatest for physical aggression and somewhat less for verbal aggression. You would also expect such inborn sex differences to appear very early in life.
Each of these predictions or hypotheses can be tested through research, and the results should indicate whether one theory is better than another at accounting for known facts and predicting new facts.
Critical Thinking: Thinking Like a Scientist
Consider the statement "Opposites attract." Do you agree with this statement? Many people answer yes without hesitation on the grounds that "Everybody knows that." Critical thinkers, however, question common knowledge. Learning to think critically is one of the "fringe benefits" of studying psychology.
When we think critically, we define problems, examine evidence, analyze assumptions, consider alternatives, and, ultimately, find reasons to support or reject an argument. To think critically, you must adopt a state of mind that is characterized by objectivity, caution, a willingness to challenge other people's opinions, and - perhaps most difficult of all - a willingness to subject your deepest beliefs to scrutiny. In other words, you must think like a scientist. Thinking critically does not come naturally. It takes practice to develop this skill.
Psychologists use a number of strategies in questioning assumptions and examining data. Here, we use the rules of psychological investigation to judge whether the previously mentioned assertion that "opposites attract" is correct:
Define the problem or the question you are investigating. Do opposites attract each other?
Suggest a theory or a reasonable explanation for the problem. People who are dissimilar balance each other in a relationship.
Collect and examine all the available evidence. Be skeptical of people's self-reports, as they may be subjectively biased. If data conflict, try to find more evidence. Research on attraction yields no support for the idea that opposites attract, whereas many studies confirm that people of similar looks, interests, age, family background, religion, values, and attitudes seek each other.
Analyze assumptions. Because balancing different people's strengths and weaknesses is a good way to form a group, you might assume it is a good basis for personal relationships as well, which would explain why people of opposite temperaments would be attracted to each other. Yet research evidence shows that such an assumption is false. Why should people of similar temperaments attract each other? One important reason is that they often belong to the same social circles. Research suggests proximity is a big factor in attraction.
Avoid oversimplifying. Don't overlook the evidence that people of similar temperaments find living together rather difficult in some ways. For example, living with someone who is as tense as you are may be harder than living with someone of calm temperament - your opposite.
Draw conclusions carefully. It seems safe to conclude that, in general, opposites don't attract, but there are specific exceptions to this general rule.
Consider every alternative interpretation. People may cite cases that conflict with your conclusion. Remember, however, that their arguments are likely to be based on subjective observations and a far narrower database than researchers have used when studying the question.
Recognize the relevance of research to events and situations. Let's say you have been thinking of dating someone whose temperament seems quite different from yours. You may decide, based on what you now know, not to rush into things but to go more slowly, testing your own observations against your knowledge of research findings. But since there are cases where opposites do attract, you may indeed find that person attractive.
THE GROWTH OF PSYCHOLOGY
Prior to about the 5th century B.C.E., nobody thought much about trying to understand human thoughts and behavior. People regarded their mental processes with awe, assuming that thoughts and emotions were the work of spirits and gods. That all changed when Greek philosophers began to speculate about how the mind works, about where thoughts and feelings come from if not from the gods, and about how the mind might affect behavior. Socrates (470-399 B.C.E.) believed that we are born with knowledge and, by reasoning correctly, we gain access to it. He also believed that our minds (souls) do not cease to exist when we die. In other words, thoughts and ideas are distinct from the world of real objects and our bodies, a concept that is known as dualism. Plato (427-347 B.C.E.) was a student of Socrates. Not surprisingly, he believed in innate knowledge that we access through careful reasoning. He also divided the world into two realms, with mind being pure and abstract, and all else physical and mundane. He also suggested that reason is responsible for balancing our desires (appetites) on the one hand with our (spirit) on the other in pursuit of reason's goals. As we will see, this notion is remarkably similar to ideas put forth by Sigmund Freud thousands of years later. Aristotle (384-322 B.C.E.) was a student of Plato but he came to very different conclusions about the sources of knowledge. In particular, he believed that we acquire knowledge by observing the physical world and using logic and reasoning to make sense of our observations. We perceive the world, remember at least some of what we have perceived, and by thinking we arrive at understanding. In other words, there is no innate knowledge. His emphasis on careful observation and reasoning about facts are precursors to the modern, scientific study of behavior.
Jump ahead to the end of the Dark Ages and the beginnings of the scientific revolution, when Rene Descartes (1596-1650) took the position that the human mind, unlike the physical world, is not subject to laws. Moreover, the mind is not observable, it controls the body; and in turn, the body provides information for the mind. You will recognize this as another example of dualism. And indeed understanding the relation between mind and body continues to challenge psychologists today. John Locke (1632-1704) took a very different view. Like Aristotle, he concluded that we gain knowledge through experience. In sharp contrast to Socrates and Plato, he said the human mind at the moment of birth is a tabula rasa, a "blank slate" that contains no innate knowledge. And unlike Descartes, he believed that even the human mind operates according to laws. Thomas Hobbes (1588-1679) went even further. He claimed that such things as "soul" and "spirit" and "mind" are meaningless. According to Hobbes, thoughts and experiences are simply by-products of the workings of our brain. In this respect, Hobbes anticipated the position of psychological behaviorists as we shall soon see. Charles Darwin (1809-1882) followed in Hobbes's path by asserting that while the mind is unobservable (and thus not a proper subject for scientific study), behavior is observable and thus open to scientific examination. Moreover, Darwin took the position that behavior evolves - behavior that contributes to the survival of a species tends to persist, while behavior that is detrimental to survival tends to disappear over time. Evolutionary psychologists today follow in that same tradition.
It was not until the late 1800s that the scientific method began to be applied to questions that had puzzled philosophers for centuries. Only then did psychology come into being as a formal, scientific discipline separate from philosophy. The history of psychology can be divided into three main stages: the emergence of a science of the mind, the behaviorist decades, and the "cognitive revolution."
The "New Psychology": A Science of the Mind
At the beginning of the 20th century, most university psychology programs were located in philosophy departments. But the foundations of the "new psychology" - the science of psychology - had been laid. Initially psychology was defined as the study of mental processes. The primary method of collecting data was introspection or self-observation, which occurred in a laboratory or on an analyst's couch.
Wilhelm Wundt and Edward Bradford Titchener: Voluntarism and Structuralism
Most psychologists agree that psychology was born in 1879, the year that Wilhelm Wundt founded the first psychological laboratory at the University of Leipzig in Germany. In the public eye, a laboratory identified a field of inquiry as "science" (Benjamin, 2000). At the outset, Wundt did not attract much attention; only four students attended his first lecture. By the mid-1890s, however, his classes were filled to capacity.
Wundt attempted to explain immediate experience and to develop ways to study it scientifically, though he also believed that some mental processes could not be studied through scientific experiments. Wundt was primarily interested in memory and selective attention - the process by which we determine what we are going to attend at any given moment. Wundt used the term voluntarism to describe his view of psychology. He believed that attention is actively controlled by intentions and motives, and that this sets human attention apart from attention in other organisms. In turn, attention controls such other psychological processes as perceptions, thoughts, and memories. In establishing a laboratory and insisting on measurement and experimentation, Wundt moved psychology out of the realm of philosophy and into the world of science.
One important product of the Leipzig lab was its students who carried the new science of psychology to universities in other countries, including the United States. G. Stanley Hall (who established the first American psychology laboratory at Johns Hopkins University in 1883), J. M. Cattell (a professor at the University of Pennsylvania in 1888, who was the first American to be called a "professor of psychology"), and British-born Edward Bradford Titchener, who went to Cornell University. Titchener's ideas differed sharply in many respects from those of his mentor (Sundqvist, 2007). Titchener was impressed by recent advances in chemistry and physics, achieved by analyzing complex compounds (molecules) in terms of their basic elements (atoms). Similarly, Titchener reasoned, psychologists should analyze complex experiences in terms of their simplest components. For example, when people look at a banana they immediately think, "Here is a fruit, something to peel and eat." But this perception is based on associations with past experience; what are the most fundamental elements, or "atoms," of thought?
Titchener broke down consciousness into three basic elements: physical sensations (what we see), feelings (such as liking or disliking bananas), and images (memories of other bananas). Even the most complex thoughts and feelings, he argued, can be reduced to these simple elements. Titchener saw psychology's role as identifying these elements and showing how they can be combined and integrated - an approach known as structuralism. Although the structuralist school of psychology was relatively short-lived and has had little long-term effect, the study of perception and sensation continues to be very much a part of contemporary psychology.
William James: Functionalism
One of the first academics to challenge structuralism was an American, William James (son of the transcendentalist philosopher Henry James, Sr., and brother of novelist Henry James). As a young man, James earned a degree in physiology and also studied philosophy on his own, unable to decide which interested him more. In psychology, he found the link between the two. In 1875, James offered a class in psychology at Harvard. He later commented that the first lecture he ever heard on the subject was his own. His writings touched on almost every issue of interest to contemporary psychologists (Austin, 2013).
James argued that Titchener's "atoms of experience" - pure sensations without associations - simply do not exist in real-life experience. Our minds are constantly weaving associations, revising experience, starting, stopping, and jumping back and forth in time. Perceptions, emotions, and images cannot be separated, James argued; consciousness flows in a continuous stream. If we could not recognize a banana, we would have to figure out what it was each time we saw one. Mental associations allow us to benefit from previous experience. When we get up in the morning, get dressed, open the door, and walk down the street, we don't have to think about what we are doing: We act out of habit. James suggested that when we repeat something, our nervous systems are changed so that each repetition is easier than the last.
James developed a functionalist theory that focused on how individuals use their perceptual abilities to adapt and function in their environment. This theory raised questions about learning, the complexities of mental life, the impact of experience on the brain, and humankind's place in the natural world that still seem current today. Although impatient with experiments, James shared Wundt and Titchener's belief that the goal of psychology was to analyze experience.
Sigmund Freud: Psychodynamic Psychology
Of all psychology's pioneers, Sigmund Freud is by far the best known - and the most controversial. A medical doctor, unlike the other figures we have introduced, Freud was fascinated by the central nervous system. He spent many years conducting research in the physiology laboratory of the University of Vienna and only reluctantly became a practicing physician. After a trip to Paris, where he studied with a neurologist who was using hypnosis to treat nervous disorders, Freud established a private practice in Vienna in 1886. His work with patients convinced him that many nervous ailments are psychological, rather than physiological, in origin. Freud's clinical observations led him to develop a comprehensive theory of mental life that differed radically from the views of his predecessors.
Freud held that human beings are not as rational as they imagine and that "free will," which was so important to Wundt, is largely an illusion. Rather, we are motivated by unconscious instincts and urges that are not available to the rational, conscious part of our mind. Other psychologists had referred to the unconscious, in passing, as a dusty warehouse of old experiences and information we could retrieve as needed. In contrast, Freud saw the unconscious as a dynamic cauldron of primitive sexual and aggressive drives, forbidden desires, nameless fears and wishes, and traumatic childhood memories. Although hidden from awareness, unconscious impulses press on the conscious mind and find expression in disguised or altered form, including dreams, mannerisms, slips of the tongue, and symptoms of mental illness, as well as in socially acceptable pursuits such as art and literature. To uncover the unconscious, Freud developed the technique of free association, in which the patient lies on a couch, recounts dreams, and says whatever comes to mind.
Freud's psychodynamic theory was controversial at the turn of the century. Many of Freud's Victorian contemporaries were shocked, not only by his emphasis on sexuality, but also by his suggestion that we are often unaware of our true motives and thus are not entirely in control of our thoughts and behavior. Conversely, members of the medical community in Vienna at the time generally held Freud's new theory in high regard, nominating him for the position of Professor Extraordinarious at the University of Vienna (Esterson, 2002). Freud's lectures and writings attracted considerable attention in the United States as well as Europe; he had a profound impact on the arts and philosophy, as well as on psychology. However, Freud's theories and methods continue to inspire heated debate.
Psychodynamic theory, as expanded and revised by Freud's colleagues and successors, laid the foundation for the study of personality and psychological disorders. His revolutionary notion of the unconscious and his portrayal of human beings as constantly at war with themselves are taken for granted today, at least in literary and artistic circles. Freud's theories were never totally accepted by mainstream psychology, however; and in recent decades his influence on clinical psychology and psychotherapy has declined.
Redefining Psychology: The Study of Behavior
We have seen that initially, psychology was defined as a science of the mind. At the beginning of the 20th century, however, a new generation of psychologists rebelled against this "soft" approach. The leader of the challenge was the American psychologist John B. Watson.
John B. Watson: Behaviorism
While Freud explored unconscious forces in Vienna, across the ocean, John B. Watson argued that the whole idea of mental life was superstition, a relic left over from the Middle Ages. In Psychology as a Behaviorist Views It (1913), Watson contended that you cannot see or even define consciousness any more than you can observe a soul. And if you cannot locate or measure something, it cannot be the subject of scientific study. For Watson, psychology was the scientific study of observable, measurable behavior - and nothing more.
Watson's view of psychology, known as behaviorism, was based on the work of the Russian physiologist Ivan Pavlov, who had won a Nobel Prize for his research on digestion. In the course of his experiments, Pavlov noticed that the dogs in his laboratory began to salivate as soon as they heard their feeder coming, even before they could see their dinner. He decided to find out whether salivation, an automatic reflex, could be shaped by learning. He began by repeatedly pairing the sound of a buzzer with the presence of food. The next step was to observe what happened when the buzzer was sounded without introducing food. This experiment clearly demonstrated what Pavlov had noticed incidentally: After repeated pairings, the dogs salivated in response to the buzzer alone. Pavlov called this simple form of training conditioning. Thus, a new school of psychology was inspired by a casual observation - followed by rigorous experiments.
Watson came to believe that all mental experiences - thinking, feeling, awareness of self - are nothing more than physiological changes in response to accumulated experiences of conditioning. Experience may write virtually anything. He held the position that if he were able to completely control the environment, he could train any healthy infant to become any kind of adult he chose, physician, lawyer, artist, or even thief or beggar (J. B. Watson, 1924).
Watson attempted to demonstrate that all psychological phenomena - even Freud's unconscious motivations - are the result of conditioning. In one of the most infamous experiments in psychology's history, Watson attempted to create a conditioned fear response in an 11-month-old boy. "Little Albert" was a secure, happy baby who enjoyed new places and experiences. On his first visit to Watson's laboratory, Albert was delighted by a tame, furry white rat, but he became visibly frightened when Watson banged a steel bar with a hammer just behind the infant's head. On his second visit, Watson placed the rat near Albert, and the moment the baby reached out and touched the rat, Watson banged the hammer. After half a dozen pairings, little Albert began crying the instant the rat was introduced, without any banging. Further experiments found that Albert was frightened by anything white and furry - a rabbit, a dog, a sealskin coat, cotton wool, and Watson wearing a Santa Claus mask (J. B. Watson & Rayner, 1920; also see Beck, Levinson, & Irons, 2009). Freud had labeled the transfer of emotions from one person or object to another "displacement," a neurotic response that he traced to the unconscious. Drawing on Pavlov, Watson called the same phenomenon "generalization," a simple matter of conditioning. As far as Watson was concerned, psychodynamic theory and psychoanalysis were "voodooism."
Watson was also interested in showing that fears could be eliminated by conditioning. Mary Cover Jones, one of his graduate students, successfully reconditioned a boy who showed a fear of rabbits (not caused by laboratory conditioning) to overcome this fear. Her technique which involved presenting the rabbit at a great distance and then gradually bringing it closer while the child was eating, is similar to conditioning techniques used by psychologists today.
B. F. Skinner: Behaviorism Revisited
Following in the footsteps of Pavlov and Watson, B. F. Skinner became one of the leaders of the behaviorist school of psychology in the mid-20th century. Like Watson, Skinner fervently believed that psychologists should study only observable and measurable behavior. He, too, was primarily interested in changing behavior through conditioning - and in discovering natural laws of behavior in the process. But Skinner added a new element to the behaviorist repertoire: reinforcement. He rewarded his subjects for behaving the way he wanted them to behave. For example, an animal was put into a special cage and allowed to explore it. Eventually, the animal reached up and pressed a lever or pecked at a disk on the wall, whereupon a food pellet dropped into the box. Gradually, the animal learned that pressing the bar or pecking at the disk always brought food. Why did the animal learn this? It learned because it was reinforced, or rewarded, for doing so. Skinner thus made the animal an active agent in its own conditioning.
Behaviorism dominated academic psychology in the United States well into the 1960s. One unintended and, at the time, largely unnoticed consequence was that psychology developed an environmental bias: Virtually every aspect of human behavior was attributed to learning and experience. Investigating evolutionary influences on behavior or studying hereditary, genetic influences on individual and group differences was considered taboo (R. B. Evans, 1999).
The Cognitive Revolution
In the late 1960s, behaviorism began to loosen its grip on the field. On one hand, research on perception, personality, child development, interpersonal relations, and other topics that behaviorists had ignored raised questions they couldn't readily explain. On the other hand, research in other fields (especially anthropology, linguistics, neurobiology, and computer science) was shedding new light on the workings of the mind. Psychologists came to view behaviorism not as an all-encompassing theory, but as only one piece of the puzzle that played an important role in the development of psychology as a science (Moore, 2010). They began to look into the "black box" of the human mind and put more emphasis on humans (and other animals) as conscious, perceptive, and alert beings; that is, as active learners, rather than passive recipients of life's lessons.
The Precursors: Gestalt and Humanistic Psychology
Even during the period that behaviorism dominated American psychology, not all psychologists had accepted behaviorist doctrines. Two schools that paved the way for the cognitive revolution were Gestalt psychology and humanistic psychology.
In Germany, psychologists Max Wertheimer, Wolfgang Kohler, and Kurt Koffka were all interested in perception, particularly in certain tricks that the mind plays on itself. For example, when we see a series of still pictures flashed at a constant rate (for example, movies or "moving" neon signs), why do the pictures seem to move? Phenomena like these launched a new school of thought, Gestalt psychology. Roughly translated from German, Gestalt means "whole" or "form." When applied to perception, it refers to our tendency to see patterns, to distinguish an object from its background, to complete a picture from a few cues. Like William James, the Gestalt psychologists rejected the structuralists' attempt to break down perception and thought into their elements. When we look at a tree, we see just that, a tree, rather than a series of isolated leaves and branches.
During the same period, the American psychologist Abraham Maslow, who studied under Gestalt psychologist Max Wertheimer and anthropologist Ruth Benedict, developed a more holistic approach to psychology, in which feelings and yearnings play a key role. Maslow referred to humanistic psychology as the "third force" - beyond Freudian theory and behaviorism. Humanistic psychologists emphasize human potential and the importance of love, belonging, self-esteem and self-expression, peak experiences (when one becomes so involved in an activity that self-consciousness fades), and self-actualization (the spontaneity and creativity that result from focusing on problems outside oneself and looking beyond the boundaries of social conventions). These psychologists focus on mental health and well-being, on self-understanding and self-improvement, rather than on mental illness.
Humanistic psychology has made important contributions to the study of motivation and emotions, as well as to the subfields of personality and psychotherapy. But this doctrine has never been totally accepted by mainstream psychology. Because humanistic psychology is interested in questions of meaning, values, and ethics, many people - including its own members - see this school of psychology more as a cultural and spiritual movement than as a branch of science. In recent years, however, positive psychologists have begun to reinvestigate some of the questions that humanistic psychologists raised a half century ago.
The Rise of Cognitive Psychology
As behaviorism fell out of favor in the late 1960s, psychology began to come full circle in what can be described as a cognitive revolution - a shift away from a limited focus on behavior toward a broad interest in such mental processes as memory, decision making, and information processing. The field evolved from a period in which consciousness was considered inaccessible to scientific inquiry to one in which researchers resumed investigating and theorizing about the mind - but now with new research methods and behaviorism's commitment to objective, empirical research. As a result of this shift in focus, even the definition of psychology changed. Psychology is still the study of human behavior, but psychologists' concept of "behavior" has been expanded to include thoughts, feelings, and states of consciousness (Glenberg, Witt & Metcalfe, 2013).
Cognitive psychology is the study of our mental processes in the broadest sense: thinking, feeling, learning, and remembering, for example. If the behaviorist model of learning resembled an old-fashioned telephone switchboard (a call or a stimulus comes in, is relayed along various circuits in the brain, and an answer or a response goes out), the cognitive model resembles a high-powered, modern computer. Cognitive psychologists are interested in the ways in which people acquire information using their cognitive "hardware" and "software," and use the results to make sense out of the world, to solve problems, and so on.
In contrast to behaviorists, cognitive psychologists believe that mental processes can and should be studied scientifically. Although we cannot observe memories or thoughts directly, we can observe behavior and make inferences about the kinds of cognitive processes that underlie that behavior. For example, we can read a lengthy story to people and then observe what they remember from that story, the ways in which their recollections change over time, and the sorts of errors that they make in recall. On the basis of systematic research of this kind, we can gain insight into the cognitive processes underlying human memory. Moreover, with the advent of new brain-imaging techniques, cognitive psychologists have begun to address questions about the neurological mechanisms that underlie such cognitive processes as learning, memory, intelligence, and emotion, giving rise to the rapidly expanding field of cognitive neuroscience (Yarkoni, Poldrack, Van Essen, & Wager, 2010).
New Directions
During much of the 20th century, psychology was divided into competing theoretical schools. Crossing theoretical lines was considered intellectual heresy. In the 21st century, by contrast, psychologists are more flexible in considering the merits of new approaches, combining elements of different perspectives as their interests or research findings dictate. As a result, new theories and initiatives are emerging.
Evolutionary Psychology
As the name indicates, evolutionary psychology focuses on the origins of behavior patterns and mental processes, the adaptive value they have or had, and the functions they serve or served in our emergence as a distinct species (Buss, 2005). Evolutionary psychologists ask, how did human beings get to be the way we are? In what ways might the roots of behavior serve to promote the survival of the species?
Evolutionary psychologists study such diverse topics as perception, language, helping others (altruism), parenting, happiness, sexual attraction, mate selection, jealousy, morality, and violence (Brosnan, 2011; Confer et al., 2010). By studying such phenomena in different species, different habitats, different cultures, and in males and females, evolutionary psychologists seek to understand the basic programs that guide thinking and behavior.
We have said that cognitive psychologists tend to see the human mind as a "general purpose" computer that requires software (experience) to process information. In contrast, many evolutionary psychologists see the mind as having "evolved psychological circuits" that predispose human beings to think and act in certain ways (Confer et al., 2010; Ermer, Cosmides, & Tooby, 2007). Further, they contend that these fixed programs evolved thousands of years ago when our ancestors lived as hunter-gatherers, although the problem-solving strategies that benefited early humans may or may not be adaptive in the modern era. Though the application of evolutionary theory to the understanding of human behavior was initially advanced by Charles Darwin himself more than a century ago (Burghardt, 2009), few psychologists adopted this perspective until recently. Today, the application of evolutionary theory to understanding human behavior has experienced a renaissance, particularly as psychologists pay increased attention to the biological foundations of behaviors, behavioral genetics and human diversity (Buss, 2011). As stated by David Buss, one of the foremost evolutionary psychologists, "Evolutionary psychology synthesizes modern evolutionary biology and psychology to penetrate some of life's deep mysteries: Why do many struggles center around sex? Why is social conflict pervasive? And what are the mechanisms of mind that define human nature?" (Buss, 2009).
Positive Psychology
Another emerging perspective is positive psychology, which traces its roots back to humanistic psychology, though the two perspectives differ in many ways (Waterman, 2013). According to this view, psychology should devote more attention to "the good life": the study of subjective feelings of happiness and well-being; the development of such individual traits as intimacy, integrity, leadership, altruism, and wisdom; and the kinds of families, cooperative lifestyles, work settings, and communities that encourage individuals to flourish (Snyder, Lopez, & Pedrotti, 2011).
Positive psychologists argue that psychologists have learned a great deal about the origins, diagnosis, and treatment of mental illness but relatively little about the origins and nurturance of mental wellness. There have been many studies of prejudice and intergroup hostility, for example, but very few about tolerance and intergroup harmony.
Today's positivists do not argue that psychologists should abandon their role in the science of healing. To the contrary, they support efforts to promote better, more widespread use of what psychologists have learned. But they argue that psychology has reached a point where building positive qualities should receive as much emphasis as repairing damage (Duckworth, Steen, & Seligman, 2005; Guomundsdottir, 2011)
Multiple Perspective of Psychology Today
Contemporary psychologists tend to see different perspectives as complementary, with each perspective contributing to our understanding of human behavior. Sometimes these theoretical perspectives mesh and enhance each other beautifully; at other times, adherents of one approach challenge their peers, arguing for one viewpoint over others. But psychologists agree that the field advances only when new evidence is added to support or challenge existing theories.
Where Are the Women?
As you read the brief history of modern psychology, you may have concluded that the founders of the new discipline were all men. But did psychology really have only fathers and no mothers? If there were women pioneers in the field, why are their names and accomplishments missing from historical accounts?
In fact, women have contributed to psychology from its beginnings. In the United States, women presented papers and joined the national professional association as soon as it was formed in 1892. Often, however, they faced discrimination. Some colleges and universities did not grant degrees to women; professional journals were reluctant to publish their work; and teaching positions were often closed to them. Despite these barriers, a number of early women psychologists made important contributions and were acknowledged by some of the men in the growing discipline.
In 1906, James McKeen Cattell published American Men of Science, which, despite its title, included a number of women, among them 22 female psychologists. Cattell rated 3 of these women as among the 1,000 most distinguished scientists in the country: Mary Whiton Calkins (1863-1930), for her analysts of how we learn verbal material and her contributions to self-psychology; Christine Ladd-Franklin (1847-1930), for her work in color vision; and Margaret Floy Washburn (1871-1939) for her pioneering research examining the role of imagery in thought processes and the experimental study of animal cognition. In addition, Mary Whiton Calkins was elected and served as the first female president of the American Psychological Association (APA) in 1905, a position also held by Margaret Floy Washburn in 1921. However, because the doors to an academic career remained closed, other early female psychologists found positions in therapeutic and other nonacademic settings; pursued careers in allied professions, such as child development and education, which were considered acceptable fields for women; or gained recognition by collaborating on research projects and books with their spouses.
In recent decades, the situation has changed dramatically. The number of women who receive PhDs in psychology has grown by leaps and bounds. For example, by 2008, the number of PhDs in psychology awarded to men had fallen to less than 30 percent (Willyard, 2011). Indeed, among members of the American Psychological Association, women now outnumber men almost 2 to 1 (64% to 36%) (American Psychological Association, 2011). No doubt some of this progress has resulted from the efforts of teachers of psychology to raise their students' awareness of the important accomplishments of female psychologists. Because female psychologists perform key research in all of the psychology subfields, you will find their work referred to in each chapter. For example, Terry Amabile has studied creativity, in particular the positive effects that exposure to creative role models can have on people. Elizabeth Loftus's research on memory has uncovered how unreliable eyewitness accounts of a crime can be. Eleanor Maccoby, Alice Eagly, and Jacqueline Eccles are prominent among the growing number of women and men who are studying sex differences in a variety of areas, such as emotionality, math and verbal ability, and helping behavior.
HUMAN DIVERSITY
In the early 20th century, the great majority of research studies were conducted by White male professors at American universities, using White male American college students as participants. This arrangement was not a conscious or deliberate decision to study just one particular group. As in the medical community and in other sciences and prestigious professions in Europe and North America, psychology took for granted that what was true of White Western males would be true for other people as well. One critical history of psychology during this period was entitled Even the Rat Was White! (Guthrie, 1976).
For students, understanding human diversity is essential. Our major cities are home to people from diverse backgrounds, with diverse values and goals, living side by side. But proximity does not always produce harmony; sometimes it leads to aggression, prejudice, and conflict. Understanding cultural, racial, ethnic, and gender differences in thinking and behavior gives us the tools to reduce some of these interpersonal tensions. Looking at human diversity from a scientific perspective will allow you to separate fact from fiction in your daily interactions. Moreover, once you understand how and why groups differ in their values, behaviors, approaches to the world, thought processes, and responses to situations, you will be better able to savor the diversity around you. Finally, the more you comprehend human diversity, and realize that the vast majority of the world's population lives in conditions very different than those experienced by Americans, the more you will appreciate the many universal features of humanity such as those cited by the anthropologist Donald Brown (1991).
The process of examining and overcoming past assumptions and biases has been slow and uneven, but a new appreciation of human diversity is taking shape (Crisp, 2010; Fiske, 2010; Herek, 2010; Medin, Bennis, & Chandler, 2010; van de Vijver, 2013). Psychologists have begun to question assumptions that are explicitly based on gender, race, and culture. Are women more likely than men to help a person in distress? Are African Americans more vulnerable to certain types of mental illnesses than are European Americans, or vice versa? Do the Japanese view children's ability to learn in the same way Americans do? Do homosexuals have different motives and emotions than heterosexuals? Research indicates that the answer to such questions often is "no."
Gender
Gender has many layers. The words male and female refer to one's biological makeup, the physical and genetic facts of being one sex or the other. Some scientists use the term sex to refer exclusively to biological differences in anatomy, genetics, or physical functioning, and gender to refer to the psychological and social meanings attached to being biologically male or female. Because distinguishing what is biologically produced from what is socially influenced is almost impossible, in our discussion of these issues, we will use the terms sex and gender interchangeably.
Gender Stereotypes
In the past, men and women led very different lives. Today, women in many societies are as likely as men to obtain higher education; to work full-time, pursue careers, start businesses; and to be active in politics. And men are more likely to be more active parents and homemakers than their fathers were. Yet, stereotypes about how the "typical male" or "typical female" looks and acts still lead to confusion and misunderstandings between the sexes. In general, our culture promotes the idea that men are dominant, strong, and aggressive, whereas women are accommodating, emotional, and affectionate. As a result, many boys learn to hide their emotions, to deny feelings of weakness even to themselves, and to fight. Many girls, by contrast, learn to hide their ambitions, to deny their talents and strengths even to themselves, and perhaps to give in. Stereotypes are rarely benign. The negative effects of these particular stereotypes on both boys and girls are significant and lasting.
Beyond our stereotypes about what males and females "typically" are like, we have general beliefs about gender roles - that is, cultural expectations regarding acceptable behavior and activities for males and females, respectively. As a rule, cultural norms change more slowly than behavior patterns. Although most modern American families depend on two salaries, the assumption that the husband should be the chief breadwinner and the wife should put her home and children first remains powerful. Working wives and mothers work a "second shift" (keeping house and caring for children) at home - as much because they feel that doing so is their responsibility and area of expertise, as because their husbands still expect them to do so (Dillaway & Pare, 2008; Konishi, 2010).
The study of gender similarities and differences has become part of mainstream psychology. Psychologists in virtually every subfield conduct research to determine whether their findings apply equally to males and females, and if not, why not. As we will see, feminist theory is not for women only.
Feminist Psychology
As the number of female psychologists has grown in recent decades, so have their concerns about traditional psychological theories, research, and clinical practices (Basow, 2010; Robb, 2006). Feminist psychologists such as Carol Gilligan make three main points. As we have noted, much of the research supporting key psychological theories, such as moral development, was based on all-male samples. Second, reports of gender differences tend to focus on the extremes, exaggerating small differences and ignoring much greater similarities. Third, the questions that psychologists ask and the topics that they study reflect what they consider to be important; male and female psychologists differ to some extent in that regard.
Beyond research and theory, contemporary feminist psychology has begun to influence every facet of psychological practice by seeking mechanisms to empower women in the community, by advocating action to establish policies that advance equality and social justice, and by increasing women's representation in global leadership. Feminists also took the lead in urging other psychologists to recognize sexual orientation as simply another aspect of human diversity.
Sexual Orientation
The term sexual orientation refers to whether a person is sexually attracted to members of the opposite sex (heterosexuality), the same sex (homosexuality), or both sexes (bisexuality). Division 44 of the American Psychological Association, "Society for the Psychological Study of Lesbian, Gay, and Bisexual Issues," was founded in 1985 to promote research and education regarding sexual orientation, for psychologists as well as the general public. Psychologists have only just begun to investigate the many sensitive issues associated with this dimension of human diversity - including such topics as the origins of sexual orientation, brain differences between heterosexual and homosexual men, discrimination and aggression toward people with different sexual orientations (Nadal, 2011), and the ethical issues that may arise if genes that influence sexual orientation are identified.
Race and Ethnicity
Race is a biological term used to refer to a subpopulation whose members have reproduced exclusively among themselves and therefore are genetically similar and distinct from other members of the same species. Most people simply take for granted the idea that the human species can be divided into a number of distinct races (Asians, Africans, Caucasians, Native Americans, and so on). However, human beings have migrated, intermarried, and commingled so frequently over time that it is impossible to identify biologically separate races. Moreover, the criteria people use to differentiate among different races are arbitrary. In the United States, we assign people to different races primarily on the basis of skin color and facial features. In central Africa, members of the Tutsi and Hutu tribes see themselves as different races, although they are similar in skin color and facial features. In spite of these different definitions, most people continue to believe that racial categories are meaningful; and as a result, race shapes peoples social identities, their sense of self, their experiences in their own and other societies, and even their health.
Whereas racial categories are based on physical differences, ethnicity is based on cultural characteristics. An ethnic group is a category of people who have migrated to another country, but still identify themselves - and are perceived by others - as distinctive because of a common homeland and history, language, religion, or traditional cultural beliefs and social practices. For example, Hispanic Americans may be Black, White, or any shade in between. What unites them is their language and culture. By the mid-1980s, there was sufficient interest among psychologists in ethnicity for the APA to create a new division (Division 45), devoted to the psychological study of ethnic minority issues. Increasing numbers of psychologists are now studying why ethnicity is so important both in our country and in others and how individuals select or create an ethnic identity and respond to ethnic stereotypes.
Racial and Ethnic Minorities in Psychology
Most ethnic minorities are still underrepresented among the ranks of American psychologists (Chandler, 2011). Why? One possibility is that when Black, Hispanic American, Native American, and other students look at the history of psychology or the psychology faculties of modern universities, they find few role models; likewise, when they look at psychological research, they find little about themselves and their realities (Strickland, 2000). One survey of psychology journals found less than 2% of the articles focused on U.S. racial and ethnic minorities (Iwamasa & Smith, 1996). Nonetheless, their small numbers have not prevented them from achieving prominence and making significant contributions to the field. For example, the late Kenneth Clark (1914-2005), a former president of the American Psychological Association, received national recognition for the important work he and his wife, the late Mamie Clark (1917-1983), did on the effects of segregation on Black children. This research was cited by the Supreme Court in the Brown v. Board of Education decision of 1954 that outlawed segregated schools in the United States.
In an effort to remedy the underrepresentation of ethnic minorities, the APA's Office of Ethnic Minority Affairs is sponsoring programs to attract ethnic-minority students to psychology (Clay, 2009; Munsey, 2009). This initiative includes summer programs for high school students, recruitment at the high school and college levels, mentor and other guidance programs, and a clearinghouse for college students who meet the requirements for graduate programs.
Psychologists are also working to uncover and overcome biases in psychological research that are related to gender, race, and ethnicity. The field of psychology is broadening its scope to probe the full range and richness of human diversity. We will consider the problem of bias in psychological research more fully.
Culture
"Humans are a cultural species" (Heine & Norenzayan, 2006, p. 251). A culture provides modes of thinking, acting, and communicating; ideas about how the world works and why people behave as they do; beliefs and ideals that shape our individual dreams and desires; information about how to use and improve technology; and, perhaps most important, criteria for evaluating what natural events, human actions, and life itself mean. All large, complex modern societies also include subcultures - groups whose values, attitudes, behavior, and vocabulary or accent distinguish them from the cultural mainstream. Most Americans participate in a number of subcultures as well as in mainstream culture.
Many of the traits we think of as defining us as human - especially language, morals, and technology - are elements of culture. Even one's sense of self is dependent on culture and subculture. In cross-cultural research, psychologists examine the way cultures and subcultures affect behavior. For example, cross-cultural research on motivation and emotions, personality, and self-esteem has called attention to a broad distinction between individualistic cultures (which value independence and personal achievement) and collectivist cultures (which value interdependence, fitting in, and harmonious relationships). Moreover, cross-cultural studies have had a significant impact on the study of gender. Anthropologist Margaret Mead's classic work, Sex and Temperament in Three Primitive Societies (1935), is still cited by feminists and others as showing that definitions of masculinity and femininity are not biological givens, but are instead created by cultures and learned by their members along with other cultural norms, which makes them subject to change. Finally, in our increasingly multicultural society, psychologists are now dealing with diverse clients, research participants, and students. To meet this challenge, psychologists and other mental health professionals have begun working to educate and train "culturally competent" professionals (Fung, Andermann, Zaretsky, & Lo, 2008; Whealin & Ruzek, 2008).
RESEARCH METHODS IN PSYCHOLOGY
To collect data systematically and objectively, psychologists use a variety of research methods.
Naturalistic Observation
Psychologists use naturalistic observation to study human or animal behavior in its natural context. One psychologist with this real-life orientation might observe behavior in a school or a factory; another might observe animals in the wild rather than viewing them in captivity. The primary advantage of naturalistic observation is that the behavior observed in everyday life is likely to be more natural, spontaneous, and varied than that observed in a laboratory.
Naturalistic observation is not without its drawbacks. Psychologists using naturalistic observation take to behavior as it comes. They cannot suddenly yell, "Freeze!" when they want to study in more detail what is going on, although in the near future smartphones may make that unnecessary (Miller, 2012). Nor can psychologists tell people to stop what they are doing because it is not what the psychologists are interested in researching. Moreover, simply describing one's impressions of "a day in the life" of a particular group or the way that different people behave in the same setting is not science. Observers must measure behavior in a systematic way, for example, by devising a form that enables them to check what people are doing at planned timed intervals.
The main drawback in naturalistic observation is observer bias. Even psychologists who are trained observers may subtly distort what they see to make it conform to what they were hoping to see. For this reason, contemporary researchers often use video that can be analyzed and scored by other researchers who do not know what the study is designed to find out. Another potential problem is that psychologists may not observe or record behavior that seems to be irrelevant. Therefore, many observational studies employ a team of trained observers who pool their notes. This strategy often generates a more complete picture than one observer could draw alone.
Despite these disadvantages, naturalistic observation is a valuable tool. After all, real-life behavior is what psychology is all about. Naturalistic observation often provides new ideas and suggests new theories, which can then be studied more systematically and in more detail in the laboratory. This method also helps researchers maintain their perspective by reminding them of the larger world outside the lab.
Case Studies
A second research method is the case study: a detailed description of one person or a few individuals. A case study usually includes real-life observation, interviews, scores on various psychological tests, and whatever other measures the researcher considers revealing. For example, the Swiss psychologist Jean Piaget developed a comprehensive theory of cognitive development by carefully studying each of his three children as they grew and changed during childhood. Other researchers have tested Piaget's theory with experiments involving larger numbers of children, both in our own culture and in others.
Like naturalistic observation, case studies can provide valuable insights but they also can have significant drawbacks. Observer bias is as much a problem here as it is with naturalistic observation. Moreover, because each person is unique, we cannot confidently draw general conclusions from a single case. Nevertheless, case studies figure prominently in psychological research. For example, the famous case of Phineas Gage, who suffered severe and unusual brain damage, led researchers to identify the front portion of the brain as important for the control of emotions and the ability to plan and carry out complex tasks.
Surveys
In some respects, surveys address the shortcomings of naturalistic observation and case studies. In survey research, a carefully selected group of people is asked a set of predetermined questions in face-to-face interviews or in questionnaires. Surveys, even those with a low-response rate, can generate a great deal of interesting and useful information at relatively low cost, but for results to be accurate, researchers must pay close attention to the survey questions (Saris & Gallhofer, 2007). In addition, the people surveyed must be selected with great care and be motivated to respond to the survey thoughtfully and carefully. For example, asking parents, "Do you ever use physical punishment to discipline your children?" may elicit the socially correct answer, "No." Asking "When was the last time you spanked your child?" is more likely to elicit honest responses, because the question is specific and implies that most parents use physical punishment - the researcher is merely asking when. At the same time, survey researchers must be careful not to ask leading questions, such as "Most Americans approve of physical punishment; do you?" Guaranteeing anonymity to participants in a survey can also be important.
Naturalistic observations, case studies, and surveys can provide a rich set of raw data that describes behaviors, beliefs, opinions, and attitudes. But these research methods are not ideal for making predictions, explaining, or determining the causes of behavior. For these purposes, psychologists use more powerful research methods.
Correlational Research
A psychologist, under contract to the U.S. Air Force, is asked to predict which applicants for a pilot-training program will make good pilots. An excellent approach to this problem would be correlational research. The psychologist might select several hundred trainees, give them a variety of aptitude and personality tests, and then compare the results with their performance in training school. This approach would tell him whether some characteristics or set of characteristics is closely related to, or correlated with, eventual success as a pilot.
Suppose that the psychologist finds that the most successful trainees score higher than the unsuccessful trainees on mechanical aptitude tests and that they are also cautious people who do not like to take unnecessary risks. The psychologist has discovered that there is a correlation, or relationship, between these traits and success as a pilot trainee. If these correlations are confirmed in new groups of trainees, then the psychologist could recommend with some confidence that the Air Force consider using these tests to select future trainees.
Correlational data are useful for many purposes, but they do not permit the researcher to explain cause and effect. This important distinction is often overlooked. Correlation means that two phenomena seem to be related: When one goes up, the other goes up (or down). In our pilot trainee example, high scores on tests of mechanical aptitude and caution predict success as a pilot trainee. But correlation does not identify the direction of influence. Does the tendency to shy away from taking risks make a trainee a good pilot? Or is the reverse true: Learning to be a skillful pilot makes people cautious? Or is there some unknown factor that causes people to be both cautious and capable of acquiring the different skills needed in the cockpit? Although the psychologist has described a relation between skill as a pilot and two other characteristics, he has no basis for drawing conclusions about cause and effect.
Despite limitations, correlational research often sheds light on important psychological phenomena. These interesting findings allow us to make some predictions, but psychologists want to move beyond simply making predictions. To explain the causes of psychological phenomena, psychologists most often use experimental research.
Experimental Research
A psychology instructor notices that on Monday mornings, most students in her class do not remember materials as well as they do later in the week. She has discovered a relationship between the day of the week and memory for course-related material. On the basis of this correlation, she could predict that every Monday thereafter, the students in her class will not absorb material as well as on other days. But she wants to go beyond simply predicting her students' behavior. She wants to understand or explain why their memories are poorer on Mondays than on other days of the week.
As a result of her own experiences and some informal interviews with students, she suspects that students stay up late on weekends and that their difficulty remembering information presented on Mondays is due to lack of sleep. This theory appears to make sense, but the psychologist wants to prove that it is correct. To determine whether lack of sleep actually affects cognitive performance, she turns to the experimental method.
Beyond selecting participants - people she can observe to test her hypothesis - the psychologist then needs to know which participants are sleep deprived. Everyone in the experiment, she decides, will be kept awake until 4:00 AM and then awakened at 7:00 AM. By manipulating the amount of time the participants sleep, the psychologist is introducing and controlling an essential element of the experimental method: an independent variable.
Next, she needs to know how well the students remember new information after they are deprived of sleep. For this, she designs a memory task made up of geometric shapes, each labeled with a nonsense word. She gives students half an hour to learn the names from this page, then takes it away and asks them to assign those same labels to geometric shapes on a new page. Performance on the memory task (the number of correct answers) thus becomes the dependent variable. According to the psychologist's hypothesis, changing the independent variable (the amount of sleep) should also change the dependent variable (performance on the memory task). Her prediction is that this group of participants, who get no more than 3 hours of sleep, should do quite poorly on the memory test.
To be sure that her experiment measures only the effects of inadequate sleep, the experimenter creates another group, containing equal numbers of males and females of the same ages with the same college board scores. The first group, the experimental group, will be subjected to the experimenter's manipulation of the independent variable - amount of sleep. Members of the second group, the control group, will be allowed to go to sleep whenever they please. If the only consistent difference between the two groups is the amount of sleep they get, the experimenter can be much more confident that differences in test performance are due to length of time they slept the night before.
The experimental method is a powerful tool, but it, too, has limitations. First, many intriguing psychological variables, such as love, hatred, or grief, do not readily lend themselves to experimental manipulation. And even if it were possible to induce such strong emotions as part of a psychological experiment, this treatment would raise serious ethical questions. In some cases, psychologists may use animals rather than humans for experiments. But some subjects, such as the ability to remember historical facts or group problem solving, cannot be studied with other species. Second, because experiments are conducted in an artificial setting, participants - whether human or nonhuman animals - may behave differently than they would in real life.
Multimethod Research
Suppose that a psychologist were interested in studying creativity. She would probably combine several of the methods we have described. She might begin her research by giving a group of college students a creativity test that she had invented to measure their capacity to discover or produce something new, and look for correlations among the students' scores on her test, their grades, and their scores on commonly used intelligence tests. Then, she might spend several weeks observing a college class and interviewing teachers, students, and parents to correlate classroom behavior and the interview data with the students' scores on the creativity test. She might then go on to test some of her ideas with an experiment by using a group of students as participants. Her findings at any point in this research program might prompt her to revise her creativity test or her understanding of creativity. Eventually, her research might provide new insights into the nature of creativity and its relationship to other mental abilities.
The Importance of Sampling
One obvious drawback to every form of research is that it is usually impossible to include everyone as participants. No one could expect to study the responses of all individuals who suffer from the irrational fears known as phobias or to record the maternal behavior of all female monkeys. No matter what research method is used, researchers almost always have to study a small sample, or subset of the population, and then use the results of that limited study to generalize about larger populations. For example, the psychology instructor who studied the effect of lack of sleep on memory assumed that her results would apply to other students in her classes (past and future), as well as to students in other classes and at other colleges.
How realistic are these assumptions? How confident can researchers be that the results of research conducted on a relatively small sample apply to the much larger population from which the sample was drawn? By reducing sampling errors social scientists have developed several techniques to improve the generalizability of their results. One technique is to select participants at random from the larger population. For example, the researcher studying pilot trainees might begin with an alphabetical list of all trainees and then select every third name on the list to be in his study. These participants would constitute a random sample from the larger group of trainees, because every trainee had an equal chance of being chosen for the study.
Another way to make sure that conclusions apply to the larger population is to pick a representative sample of the population being studied. For example, researchers looking for a representative cross section of Americans would want to ensure that the proportion of males and females in the study matched the national proportion, that the number of participants from each state matched the national population distribution, and so on. The importance of sampling has received a great deal of attention recently as psychologists have become increasingly sensitive to the great diversity among humans.
Human Diversity and Research
Psychologists have recently begun to question early assumptions that the results of research conducted with White male participants would also apply to women, to people of other racial or ethnic groups, and to people of different cultures. Similarly, do feminist theories, developed by and tested primarily with White, college-educated women, apply to women of color (B. Roth, 2004)? Research indicates that people's gender, race, ethnic background, and culture often have profound effects on their behavior. That is why psychologists have raised the possibility that perhaps we need "different psychologies" to account for the wide diversity of human behaviors.
Diversity also presents a challenge to the way that research is conducted. The gender, race, or ethnicity of the experimenter may also introduce subtle, unintended biases. For example, some early research concluded that women were more likely than men to conform to social pressure in the laboratory. Later research revealed no gender differences, however, when the experimenter is female (Eagly & Carli, 1981). More recent studies continue to demonstrate that the gender of the experimenter may produce different results when testing male versus female participants (Lundstrom & Olsson, 2005).
Similarly, evidence suggests that the results of research with African American participants may be significantly affected by the race of the experimenter (Graham, 1992; Weisse, Foster, & Fisher, 2005). For example, African Americans score higher on IQ and other tests when the person administering the test is also an African American (Graham, 1992).
ETHICS AND PSYCHOLOGY: RESEARCH ON HUMANS AND ANIMALS
If the college or university you attend has a research facility, you may have a chance to participate in a psychology experiment. You will probably be offered a small sum of money or class credit to participate. But you may not learn the true purpose of the experiment until after it's over. Is this deception necessary to the success of psychology experiments? And what if the experiment causes you discomfort? Before answering, consider the ethical debate that flared up in 1963 when Stanley Milgram published the results of several experiments he had conducted (Perry, 2013).
Milgram hired people to participate in what he said was a learning experiment. In a typical session, a young man would arrive at the laboratory to participate. He was met by a stern-faced researcher in a lab coat; another man in street clothes was sitting in the waiting room. The researcher explained that he was studying the effects of punishment on learning. When the two men drew slips out of a hat, the participant's slip said "teacher." The teacher watched as the "learner" was strapped into a chair and an electrode attached to his wrist. Then the teacher was taken into an adjacent room and seated at an impressive-looking "shock generator" with switches from 15 to 450 volts (V), labeled "Slight Shock," "Very Strong Shock," up to "Danger: Severe Shock," and, finally, "XXX." The teacher's job was to read a list of paired words, which the learner would attempt to memorize and repeat. The teacher was instructed to deliver a shock whenever the learner gave a wrong answer and to increase the intensity of the shock each time the learner made a mistake. At 90 V, the learner began to grunt; at 120 V, he shouted, "Hey, this really hurts!" At 150 V, he demanded to be released, and at 270 V, his protests became screams of agony. Beyond 330 V, the learner appeared to pass out. If the teacher became concerned and asked whether he could stop, the experimenter politely but firmly replied that he was expected to continue, that this experiment was being conducted in the interest of science.
Animal Research
In recent years, serious questions have also been raised about the ethics of using animals in psychological research (Herzog, 2005). Psychologists study animal behavior to shed light on human behavior. Crowding mice into small cages, for example, has yielded valuable insights into the effects of overcrowding on humans. Animals are used in experiments in which it would be clearly unethical to use human participants - such as studies involving brain lesions (requiring cutting into the brain). In fact, much of what we know about sensation, perception, drugs, emotional attachment, and the neural basis of behavior is derived from animal research (Ringach & Jentsch, 2009). Yet, animal protectionists and others question whether it is ethical to use nonhuman animals, which cannot give their consent to serve as subjects in psychological research (Greek & Greek, 2010).
In its "Ethical Principles of Psychologists and Code of Conduct," the American Psychological Association (2010) has defined the standards that apply to the use of animals in research:
a. Psychologists acquire, care for, use, and dispose of animals in compliance with current federal, state, and local laws and regulations, and with professional standards.
b. Psychologists trained in research methods and experienced in the care of laboratory animals supervise all procedures involving animals and are responsible for ensuring appropriate consideration of their comfort, health, and humane treatment.
c. Psychologists ensure that all individuals under their supervision who are using animals have received instruction in research methods and in the care, maintenance, and handling of the species being used, to the extent appropriate to their role.
d. Psychologists make reasonable efforts to minimize the discomfort, infection, illness, and pain of animal subjects.
e. Psychologists use a procedure subjecting animals to pain, stress, or privation only when an alternative procedure is unavailable and the goal is justified by its prospective scientific, educational, or applied value.
f. Psychologists perform surgical procedures under appropriate anesthesia and follow techniques to avoid infection and minimize pain during and after surgery.
g. When it is appropriate that an animal's life be terminated, psychologists proceed rapidly, with an effort to minimize pain and in accordance with accepted procedures.
These principles have been expanded by the APA's Committee on Animal Research and Ethics (CARE) into a full set of guidelines for psychologists who use animals in research (American Psychological Association, 2011).