Psychology Chapter 1, 2 & 3 Exam Study Guide PDF
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This document is a study guide for a psychology course covering introductory psychology concepts including research methods and the central and peripheral nervous system.
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hapter 1 Introducing psychology C The people described next all hold truly interesting jobs. What do you think they studied to qualify for those jobs? See if you can fill in the blank next to each job description with one of the fields of study listed in Table 1.1. Kri...
hapter 1 Introducing psychology C The people described next all hold truly interesting jobs. What do you think they studied to qualify for those jobs? See if you can fill in the blank next to each job description with one of the fields of study listed in Table 1.1. Kristen Beyer works for the Federal Bureau of Investigation, where she develops questionnaires and conducts interviews aimed at identifying common features in the backgrounds of serial killers. David Buss, a professor at the University of Texas, conducts research and teaches courses on how evolution influences aggression, the choice of sexual partners, and other aspects of people’s social behavior. Anne Marie Apanovitch is employed by a drug company to study which of the company’s marketing strategies are most effective in promoting sales. Rebecca Snyder studies the giant pandas at Zoo Atlanta in an effort to promote captive breeding and ultimately increase the wild population of this endangered species. Michael Moon’s job at a software company is to find new ways to make Internet web sites more informative and easier to navigate. Elizabeth Kolmstetter works at the Transportation Security Administration, where, following the September 11, 2001, terrorist attacks, she took charge of a program to establish higher standards for hiring and training security screeners at U.S. airports. Marissa Reddy, codirector of the U.S. Secret Service’s Safe Schools initiative, tries to prevent school shootings by identifying risk factors for violent behavior in high school students. Sharon Lundgren, founder of Lundgren Trial Consulting, Inc., helps prepare witnesses to testify in court, conducts mock trials in which attorneys rehearse their questioning strategies, and teaches attorneys how to present themselves and their evidence in the most convincing way. Evan Byrne works at the National Transportation Safety Board, where he investigates the role of memory lapses, disorientation, errors in using equipment, and other human factors in causing airplane crashes. Karen Orts, a captain in the U.S. Air Force, is chief of mental health services at an air base, where, among other things, she provides psychotherapy to military personnel suffering combat-related stress disorders and teaches leadership courses to commissioned and noncommissioned officers. Because Captain Orts offers psychotherapy, you probably guessed that she is a psychologist, but what academic field did you associate with Rebecca Snyder, who studies giant pandas? It would have been perfectly reasonable to assume that she is a zoologist, but she, too, is a psychologist. So is Evan Byrne, whose work on web site design might suggest that he was a computer science major. And although haron Lundgren spends her time working with witnesses and conducting mock trials, she is a S psychologist, not a lawyer. The fact is that all these people are psychologists! They may not all fit your image of what psychologists do, but as you will see in this chapter and throughout this book, psychology is much broader and more diverse than you might have expected. T In other words, there are many different kinds of psychologists, doing all sorts of fascinating work in one or more of psychology’s many specialty areas, or subfields. Most of these people took their first psychology course without realizing how many of these subfields there are or how many different kinds of jobs are open to psychologists. But like the people we have just described, they found something in psychology—perhaps something unexpected—that captured their interest, and they were hooked. And who knows? By the time you have finished this book and this course, you may have found some aspect of psychology so compelling that you will want to make it your life’s work, too. Or not. At the very least, we hope you enjoy learning about psychology, about the work of psychologists, and about how that work benefits people everywhere. The World of Psychology: An Overview is the science that seeks to understand behavior and mental processes and to apply that understanding in the service of human welfare. It is a science that covers a lot of territory, as illustrated by the vastly different jobs that occupy the ten psychologists we described. They are all psychologists because they are all involved in studying, predicting, improving, or explaining some aspect of behavior and mental processes. To begin to appreciate all the things that are included under the umbrella of behavior and mental processes, take a moment to think about how you would answer this question: Who are you? Would you describe your personality, your 20/20 vision, your interests and goals, your skills and accomplishments, your IQ, your cultural background, or perhaps a physical or emotional problem that bothers you? You could have listed these and dozens of other things about yourself, and every one of them would reflect some aspect of what psychologists mean by behavior and mental processes. It is no wonder, then, that this book’s table of contents includes so many different topics, including some—such as vision and hearing—that you might not have expected to see in a book about psychology. The topics have to be diverse in order to capture the full range of behaviors and mental processes that make you who you are and that come together in other ways in people of every culture around the world. Some of the world’s half-million psychologists focus on what can go wrong in behavior and mental processes—on psychological disorders, problems in childhood development, stress-related illnesses, and the like—while others study what goes right. They explore, for example, the factors that lead people to be happy and satisfied with their lives, to achieve at a high level, to be creative, to help others, and to develop their full potential as human beings. This focus on what goes right, on the things that make life most worth living, has become known as (e.g., Peterson, 2006; Seligman & Csikszentmihalyi, 2000; Snyder & Lopez, 2007), and you will see many examples of it in the research described throughout this book. Subfields of Psychology hen psychologists choose to focus their attention on certain aspects of behavior W and mental processes, they enter one of psychology’s subfields. Let’s take a quick look at the typical interests and activities of psychologists in each subfield. We will describe their work in more detail in later chapters. psychology The science of behavior and mental processes. positive psychology A field of research that focuses on people’s positive experiences and characteristics, such as happiness, optimism, and resilience. positive psychology Psychology The World of Psychology: An Overview 3 A. Engineering B. Criminal Justice C. Computer Science D. Law E. Psychology F. Advertising G. Biology H. Education I. Zoology J. Business Administration Try matching educational backgrounds with the people described at the beginning of the chapter by writing the correct field of study next to each person’s job description. TABLE 1.1 What’s My Line? TRY THIS TRY THIS 4 CHAPTER 1 Introducing Psychology Biological Psychology , also called physiological psychologists, use high-tech scanning devices and other methods to study how biological processes in the brain and other organs affect, and are affected by, behavior and mental processes (see Figure 1.1). Have you ever experienced déjà vu, the feeling that a new experience, such as entering an unfamiliar house, has actually happened to you before? Biological psychologists studying this illusion suggest that it may be due to a temporary malfunction in the brain’s ability to combine incoming information from the senses, creating the impression of two “copies” of a single event (Brown, 2004). In the chapter on biological aspects of psychology, we describe biological sychologists’ research on many other topics, such as how your brain controls your p movements and speech and what organs help you to cope with stress and fight disease. Developmental Psychology describe the changes in behavior and mental processes that occur from birth through old age and try to understand the causes and effects of those changes (see Figure 1.2). Their research on the development of memory and other mental abilities, for example, is used by judges and attorneys in deciding how old a child has to be in order to serve Developmental psychologists Biological psychologists FIGURE 1.1 Visualizing Brain Activity Magnetic resonance imaging (MRI) techniques allow biological psychologists to study the brain activity accompanying various mental processes. This study found that males (left) and females (right) show different patterns of brain activity (indicated by the brightly colored areas) while reading (Shaywitz et al., 1995). biological psychologists Psychologists who analyze the biological factors influencing behavior and mental processes. Drawing by a nine-year-old Drawing by an eleven-year-old FIGURE 1.2 Where Would You Put a Third Eye? In a study of how thinking processes develop, children were asked to show where they would place a third eye, if they could have one. Nine-year-old children, who were still in an early stage of mental development, drew the extra eye between their existing eyes, “as a spare.” Having developed more advanced thinking abilities, eleven-year-olds drew the third eye in more creative places, such as the palm of the hand “so I can see around corners” (Shaffer, 1973). as a reliable witness in court or to responsibly choose which divorcing parent to live with. The chapter on human development describes other research by developmental psychologists and how it is being applied in areas such as parenting, evaluating day care, and preserving mental capacity in elderly people. Cognitive Psychology Stop reading for a moment and look left and right. Your ability to follow this suggestion, to recognize whatever you saw, and to understand the words you are reading right now are the result of mental, or cognitive, abilities. Those abilities allow you to receive information from the outside world, understand it, and act on it. (some of whom prefer to be called experimental psychologists) study mental abilities such as sensation and perception, learning and memory, thinking, consciousness, intelligence, and creativity. Cognitive psychologists have found, for example, that we don’t just receive incoming information—we mentally manipulate it. Notice that the drawing in Figure 1.3 stays physically the same, but two different versions emerge, depending on which of its features you emphasize. Applications of cognitive psychologists’ research are all around you. Research by those whose special interest is —also known as human factors—has helped designers create computer keyboards, mobile phones, Internet web sites, aircraft instrument panels, nuclear power plant controls, and even TV remotes that are more logical, easier to use, and less likely to cause errors. You will read more about human factors research and many other aspects of cognitive psychology in several chapters of this book. Personality Psychology study similarities and differences among people. Some of them use tests, interviews, and other measures to A Bad Design Consultation by human factors psychologists would surely have improved the design of this self-service gasoline pump. The pump will not operate until you press the red “start” button under the yellow “push to” label (see enlargement at the upper right). The button is difficult to locate among all the other signs and stickers. Such user-unfriendly designs are all too common these days (e.g., Cooper, 2004; visit www.baddesigns.com for some amazing examples). Photograph courtesy of www.baddesigns.com. developmental psychologists Psychologists who seek to understand, describe, and explore how behavior and mental processes change over a lifetime. cognitive psychologists Psychologists who study the mental processes underlying judgment, decision making, problem solving, imagining, and other aspects of human thought or cognition. Also called experimental psychologists. engineering psychology A field in which psychologists study human factors in the use of equipment and help designers create better versions of that equipment. personality psychologists Psychologists who study the characteristics that make individuals similar to, or different from, one another. ersonality psychologists P FIGURE 1.3 Husband and Father-in-Law This figure is called “Husband and Father-in-Law” (Botwinick, 1961) because you can see an old man or a young man, depending upon how you mentally organize its features. The elderly father-in-law faces to your right and is turned slightly toward you. He has a large nose, and the dark areas represent his coat pulled up to his protruding chin. However, the tip of his nose can also be seen as the tip of a younger man’s chin; the younger man is in profile, also looking to your right, but away from you. The old man’s mouth is the young man’s neckband. Both men are wearing a broad-brimmed hat. engineering psychology Cognitive psychologists The World of Psychology: An Overview 5 TRY THIS TRY THIS compare individuals on characteristics such as openness to experience, emotionality, reliability, agreeableness, and sociability. Personality psychologists also study the characteristics of people who are prejudiced against others, who tend to be pessimistic or depressed, or even who claim to have been abducted by space aliens. As described in the personality chapter, their research has been applied in the diagnosis of mental disorders, and in the identification of people who are most likely to develop stress-related health problems. On the positive side, research by personality psychologists is helping to identify, understand, and encourage personality characteristics, such as optimism, that are associated with the resilience that allows some people to survive, and even thrive in the face of stress and to find happiness in life (Linley & Joseph, 2004; Snyder & Lopez, 2006, 2007). Clinical, Counseling, Community, and Health Psychology and conduct research on the causes of mental disorders and offer services to help troubled people overcome those disorders. They have found, for example, that many irrational fears, called phobias, are learned through the bad experiences people have with dogs, public speaking, or whatever, and that fearful people can literally be taught to overcome their fears. Research by other clinical psychologists has resulted in a listing of treatment methods that are most ffective with particular kinds of disorders. e work to ensure that psychological services reach the homeless and others who need help but tend not to seek it. They also try to prevent psychological disorders by promoting people’s resilience and other personal strengths, and by working with community leaders and neighborhood organizations to improve local schools and reduce the crime, poverty, and other stressful conditions that so often lead to disorders. study the effects of behavior on health, as well as the effects that illness has on people’s behavior and emotions. Their research is applied in programs that help people to cope effectively with illness, as well as to reduce the risk of cancer, heart disease, and stroke by giving up smoking, eating a healthy diet, and exercising more. You can read more about the work of clinical, counseling, community, and health psychologists in the chapters on health, stress, and coping; psychological disorders; and treatment of psychological disorders. Health psychologists Community psychologists clinical and counseling psychologists Psychologists who seek to assess, understand, and change abnormal behavior. community psychologists Psychologists who work to obtain psychological services for people in need of help and to prevent psychological disorders by working for changes in social systems. health psychologists Psychologists who study the effects of behavior and mental processes on health and illness, and vice versa. educational psychologists Psychologists who study methods by which instructors teach and students learn and who apply their results to improving those methods. psychologists counseling psychologists Clinical Getting Ready for Surgery Health psychologists have learned that when patients are mentally prepared for a surgical procedure, they are less stressed by it and recover more rapidly. Their research is now routinely applied in hospitals through programs in which children and adults are given more information about what to expect before, uring, and after their operations. d 6 CHAPTER 1 Introducing Psychology Educational and School Psychology conduct research and develop theories about teaching and learning. The results of their work are applied in programs designed to improve teacher training, refine school curricula, reduce dropout rates, and help students learn more efficiently. For example, they have supported the use of the “jigsaw” technique, a type of classroom activity, described in the social cognition chapter, in which children from various ethnic groups must work together to complete a task or solve a problem. These cooperative experiences appear to promote learning, generate mutual respect, and reduce intergroup prejudice (Aronson, 2004). traditionally specialized in IQ testing, diagnosing learning disabilities and other academic problems, and setting up programs to improve students’ achievement and satisfaction in school. Today, however, they are also involved in activities such as early detection of students’ mental health problems and crisis intervention following school violence (Benjamin & Baker, 2004; Elliot, Reynolds, & Kratochwill, 2006). Social Psychology study the ways that people think about themselves and others and how people influence one another. Their research on social persuasion has been applied to public health campaigns aimed at preventing the spread of AIDS and promoting the use of seat belts, not to mention the creation of compelling advertisements. Social psychologists also explore how peer pressure affects us, what determines whom we like (or even love), and why and how prejudice forms. They have found that although we may pride ourselves on not being prejudiced, we may actually hold unconscious negative beliefs about certain groups that affect the way we relate to people from those groups (Vanman et al., 2004). The chapters on social cognition and social influence describe these and many other examples of research in social psychology. Industrial/Organizational Psychology study leadership, stress, competition, pay scales, and other factors that affect the efficiency, productivity, and satisfaction of workers and the organizations that employ them. They conduct research on topics such as increasing the motivation of current employees and helping companies select the best new workers. They also explore the ways in which businesses and industrial organizations work—or fail to Got a Match? Some commercial dating and matchmaking services apply social psychologists’ research on interpersonal attraction in an effort to pair up people whose characteristics are most likely to be compatible. school psychologists Psychologists who test IQs, diagnose students’ academic problems, and set up programs to improve students’ achievement. ocial psychologists Psychologists s who study how people influence one another’s behavior and mental processes, individually and in groups. industrial/organizational psychologists Psychologists who study ways to improve efficiency, productivity, and satisfaction among workers and the organizations that employ them. ogists Industrial/organizational psycholSocial psychologists School psychologists Educational psychologists The World of Psychology: An Overview 7 work—and they make recommendations for helping them to work better (Spector, 2003). Companies all over the world are applying research by industrial/organizational psychologists to foster the development of positive organizational behavior (Luthans, 2003; Wright, 2003) through more effective employee training programs, ambitious but realistic goal-setting procedures, fair and reasonable evaluation tools, and incentive systems that motivate and reward outstanding performance. Quantitative Psychology develop and use statistical tools to analyze vast amounts of data collected by their colleagues in many other subfields (e.g., Keselman et al., 2004). These tools help to evaluate the reliability and validity of psychological tests, to trace the relationships between childhood experiences and adult behaviors, and even to estimate the relative contributions of heredity and environment in determining intelligence. To what extent are people born smart—or not so smart—and to what extent are their mental abilities created by their environments? This is one of the hottest topics in psychology today, and quantitative psychologists are right in the middle of it. Other Subfields Our list of psychology’s subfields is still not complete. There are , who use visualization and relaxation training programs, for example, to help athletes reduce excessive anxiety, focus attention, and make other changes that let them perform at their best. assist in jury selection, evaluate defendants’ mental competence to stand trial, and deal with other issues involving psychology and the law. And study the effects of the environment on people’s behavior and mental processes. The results of their research are applied by architects and interior designers as they plan or remodel residence halls, shopping malls, auditoriums, hospitals, prisons, offices, and other spaces to make them more comfortable and functional for the people who will occupy them. There are also neuropsychologists, military psychologists, consumer psychologists, rehabilitation psychologists, and more. Further information about the subfields we have mentioned and some that we haven’t is available in books (e.g., Stec & Bernstein, 1999; Super & Super, 2001), as well as on web sites of the American Psychological Association (www.apa.org) nd the Association for Psychological Science (www.psychologicalscience.org). a Where do the psychologists in all these subfields work? Table 1.2 contains the latest figures on where the approximately 160,000 psychologists in the United States find employment, as well as the kinds of things they typically do in each setting. environmental psychologists quantitative psychologists Psychologists who develop and use statistical tools to analyze research data. sport psychologists Psychologists who explore the relationships between athletic performance and such psychological variables as motivation and emotion. forensic psychologists Psychologists who assist in jury selection, evaluate defendants’ mental competence to stand trial, and deal with other issues involving psychology and the law. environmental psychologists Psychologists who study the effects of the physical environment on behavior and mental processes. Forensic psychologists sport psychologists Quantitative psychologists Working Underground Before moving its data-processing center to the basement of a new office building, executives of a large corporation consulted an environmental psychologist. They wanted to know how the employees’ performance and morale might be affected by working in a windowless space. The psychologist described the possible negative effects and, to combat those effects, recommended that architects create shafts that let in natural light. He also suggested that the area should include plants and artwork depicting nature’s beauty (Sommer, 1999). 8 CHAPTER 1 Introducing Psychology Linkages Within Psychology and Beyond We have listed psychology’s subfields as though they were separate, but they often overlap, and so do the activities of the psychologists working in them. When developmental psychologists study the changes in children’s thinking skills, for example, their research is linked to the research of cognitive psychologists. Similarly, iological psychologists have one foot in clinical psychology when they look at how b chemicals in the brain affect the symptoms of depression. And when social psychologists apply their research on cooperation to promote group learning activities in the classroom, they are linking up with educational psychology. Even when psychologists work mainly in one subfield, they are still likely to draw on, and contribute to, knowledge in other subfields. So if you want to understand psychology as a whole, you have to understand the linkages among its subfields. To help you recognize these linkages, we highlight three of them in a Linkages diagram at the end of each chapter—similar to the one shown here. Each linkage is represented by a question that connects two subfields, and the page numbers in parentheses tell you where you can read more about each question. We pay particular attention to one question in each diagram by discussing it in a special Linkages section. If you look at the Linkages diagrams and follow the links where they lead, the relationships among psychology’s many subfields will become much clearer. We hope you find this kind of detective work to be interesting and that The World of Psychology: An Overview 9 Source: 2003 Doctorate Employment Survey, APA Research Office (APA, 2006). Colleges, universities, and professional schools Teaching, research, and writing, often in collaboration with colleagues from other disciplines Mental health facilities (e.g., hospitals, clinics, counseling centers) Testing and treatment of children and adults Private practice (alone or in a group of psychologists) Testing and treatment of children and adults; consultation to business and other organizations Business, government, and organizations Testing potential employees; assessing employee satisfaction; identifying and resolving conflicts; improving leadership skills; offering stress management and other employee assistance programs; improving equipment design to maximize productivity and prevent accidents Testing mental abilities and other characteristics; identifying problem children; consulting with parents; designing and implementing programs to improve academic performance Teaching prison inmates; research in private institutes; advising legislators on educational, research, or public olicy; administering research funds; research on p effectiveness of military personnel; etc. Work Setting Typical Activities Percentage of Psychologists Schools (including those for developmentally disabled and emotionally disturbed children) Other 3.8% 7.6% 24.5% 40.4% 17.9% 5.5% The fact that psychologists can work in such a wide variety of settings and do so many interesting—and often well-paying— jobs helps account for the popularity of psychology as an undergraduate major (Fogg, Harrington, & Harrington, 2005; National Center for Education Statistics, 2003). Psychology courses also provide excellent background for students planning to enter medicine, law, business, and many other fields. TABLE 1.2 Typical Activities and Work Settings for Psychologists 10 CHAPTER 1 Introducing Psychology LINKAGES it will lead you to look for the many other linkages that we did not mention. Tracing linkages might even improve your grade in the course, because it is often easier to remember material in one chapter by relating it to linked material in other chapters. Links to Other Fields Much as psychology’s subfields are linked to one another, psychology itself is linked to many other fields. Some of these linkages are based on interests that psychologists share with researchers from other disciplines. For example, psychologists are working with computer scientists and engineers on artificial-intelligence machines that rival humans in their ability to recognize voices and images, to reason, and to make decisions. Psychologists are also collaborating with specialists in neuroanatomy, neurophysiology, neurochemistry, genetics, and other disciplines in the field known as neuroscience. The goal of this multidisciplinary research enterprise is to examine the structure and function of the nervous system in animals and humans at levels ranging from the individual cell to overt behavior. Someday, biological psychologists, like the colleagues with whom they work, may be known simply as “neuroscientists.” Many of the links between psychology and other disciplines appear when research conducted in one field is applied in the other. For example, biological psychologists are learning about the brain with scanning devices developed by computer scientists, physicists, and engineers. Economists are using research by psychologists to better understand the thought processes that influence people’s decisions about investments and other financial matters. In fact, one psychologist, Daniel Kahneman, recently won a Nobel Prize in economics for his work in this area. Other psychologists’ research on memory has influenced how lineups are displayed to eyewitnesses attempting to identify criminals, how attorneys question eyewitnesses in court, and how lawyers and judges question witnesses and instruct juries (Memon, Vrij, & Bull, 2004). And psychological studies of the effect of brain disorders on elderly patients’ mental abilities is shaping doctors’ recommendations about when those patients should stop driving cars (Reger et al., 2004). This book is filled with examples of other ways in which psychological theories and research have been applied to health care, law, business, engineering, architecture, aviation, public health, and sports, to name just a few. Research: The Foundation of Psychology The knowledge that psychologists share across subfields and with other disciplines stems from the research they conduct on many aspects of behavior and mental CHAPTER 1 CHAPTER 5 CHAPTER 18 CHAPTER 16 LINKAGES What makes some people so aggressive? (ans. on p. 737) Does psychotherapy work? (ans. on p. 664) Can subliminal messages help you lose weight? (ans. on p. 157) PERCEPTION TREATMENT OF PSYCHOLOGICAL DISORDERS SOCIAL INFLUENCE INTRODUCING PSYCHOLOGY By staying alert to the many linkages among psychology’s subfields as you read this book, you will come away not only with threads of knowledge about each subfield but also with an ppreciation of the fabric of psychology a as a whole. We discuss one linkage in detail in each chapter in a special Linkages section. processes. So instead of just speculating about why, for example, people eat too much or too little, psychologists look for answers by using the methods of science. This means that they perform experiments and other scientific procedures to systematically gather and analyze information about behavior and mental processes and then base their conclusions—and their next questions—on the results of those procedures. To take just one example related to eating, let’s consider a fascinating study conducted by Paul Rozin and his associates (Rozin et al., 1998) on what causes people to begin and end a meal. Suppose you have just finished a big lunch at your favorite restaurant when a server gets mixed up and brings you another plate of the same food that was meant for someone else. You would almost certainly send it away, but why? Decisions to start eating or stop eating are affected by many biological factors, including signals from your blood that tell your brain how much “fuel” you have available. Rozin was interested in how these decisions are affected by psychological factors, such as being aware that you have already eaten. For example, what if you didn’t remember that you just had lunch? Would you have started eating that second plate of food? To explore this question, Rozin conducted a series of tests with R. H. and B. R., two men who had suffered a kind of brain damage that left them unable to remember anything for more than a few minutes. (You can read more about this condition, called anterograde amnesia, in the memory chapter.) The men were tested individually, on three different days, in a private room where they sat with a researcher at lunchtime and were served a tray of their favorite food. Before and after eating, they were asked to rate their hunger on a scale from 1 (extremely full) to 9 (extremely hungry). Once lunch was over, the tray was removed, and the researcher continued chatting, making sure that each man drank enough water to clear his mouth of food residue. After ten to thirty minutes, a hospital attendant reentered with an identical meal tray and announced “Here’s lunch.” These men had no memory of having eaten lunch already, but would signals from their stomachs or their blood be enough to keep them from eating another one? Apparently not. Table 1.3 shows that, in every test session, R. H. and B. R. ate all or part of the second meal and, in all but one session, ate at least part of a third lunch that was offered to them ten to thirty minutes after the second one. Rozin Linking Psychology and Law Cognitive psychologists’ research on the quirks of human memory has led to revised guidelines for police and prosecutors when dealing with crime witnesses (U.S. Department of Justice, 1999). These guidelines warn that asking itnesses leading questions (e.g., “Do w you remember seeing a gun?”) can distort their memories and that false accusations are less likely if witnesses are told that the real criminal might not be in a lineup or in a group of photos (Doyle, 2005). The World of Psychology: An Overview 11 conducted similar tests with J. C. and T. A., a woman and a man who had also suffered brain damage but who still had normal memory for recent events. In each of two test sessions, these people finished their lunch but refused the opportunity to eat a second one. These results suggest that the memory of when we last ate can indeed be a factor in guiding decisions about when to eat again. They also support a conclusion described in the motivation and emotion chapter, namely that eating is controlled by a complex combination of biological, social, cultural, and psychological factors. As a result, we may eat when we think it is time to eat, regardless of what our bodies tell us about our physical need to eat. Rozin’s study illustrates the fact that although psychologists often begin with speculation about behavior and mental processes, they take additional steps toward understanding those processes. Using scientific methods to test their ideas, they reach informed conclusions and generate new questions. Even psychologists who don’t conduct research still benefit from it. They are constantly applying the results of their colleagues’ studies to improve the quality, accuracy, and effectiveness of their teaching, writing, or service to clients and organizations. In the developing field of performance psychology, for example, practicing clinical psychologists are combining their psychotherapy skills with research from cognitive, industrial/organizational, and sport psychology to help business executives, performing artists, and athletes to excel (Berman & Bradt, 2006; Hamilton & Robson, 2006; Harmison, 2006). The rules and methods of science that guide psychologists in their research are summarized in the chapter on research in psychology. We have placed that chapter early in the book to highlight the fact that without scientific research methods and the foundation of evidence they provide, psychologists’ statements and recommendations Session B. R. (Amnesia) R. H. (Amnesia) J. C. T. A. One Meal 1 Finished (7/8) Partially eaten (7/6) Finished (5/2) Finished (5/4) Meal 2 Finished (2/5) Partially eaten (7/7) Rejected (0) Rejected (3) Meal 3 Rejected (3) Partially eaten (7/7) — — Two Meal 1 Finished (6/5) Partially eaten (7/6) Finished (7/2) Finished (7/3) Meal 2 Finished (5/3) Partially eaten (7/6) Rejected (1) Rejected (3) Meal 3 Partially eaten (5)a Partially eaten (7/6) — — Three Meal 1 Finished (7/3) Partially eaten (7/6) — — Meal 2 Finished (2/3) Partially eaten (7/6.5) — — Meal 3 Partially eaten (5/3) Partially eaten (7.5) — — B. R. began eating his third meal but was stopped by the researcher, presumably to avoid a illness. Source: Adapted from Rozin et al. (1998). Here are the results of a study in which brain-damaged people were offered a meal shortly after having eaten an identical meal. Their hunger ratings (1–9, where 9 extremely hungry) before and after eating are shown in parentheses. B. R. and R. H. had a kind of brain damage that left them unable to remember recent events (anterograde amnesia); J. C. and T. A. had normal memory. These results suggest that the decision to start eating is determined partly by knowing when we last ate. Notice that hunger ratings, too, were more consistently affected by eating for the people who remembered having eaten. TABLE 1.3 The Role of Memory in Deciding When to Eat 12 CHAPTER 1 Introducing Psychology about behavior and mental processes would carry no more weight than those of astrologers, psychics, or tabloid journalists. Accordingly, we will be relying on the results of psychologists’ scientific research when we tell you what they have discovered so far about behavior and mental processes and also when we evaluate their efforts to apply that knowledge to improve the quality of human life. A Brief History of Psychology The birth date of modern psychology is usually given as 1879, the year that Wilhelm Wundt (pronounced “voont”) established the first formal psychology research laboratory at the University of Leipzig, Germany (Benjamin, 2000). However, the roots of psychology can be traced back through centuries of history in philosophy and science. Since at least the time of Socrates, Plato, and Aristotle in ancient Greece, there has been debate about where human knowledge comes from, the nature of the mind and soul, the relationship of the mind to the body, and whether it is possible to scientifically study such things (Wertheimer, 2000). The philosophy of empiricism was particularly important to the development of scientific psychology. Beginning in the seventeenth century, proponents of empiricism—especially the British philosophers John Locke, George Berkeley, and David Hume—challenged the claim, made by philosophers as far back as Plato, that some knowledge is innate. Empiricists argued instead that what we know about the world comes to us through experience and observation, not through imagination or intuition. This view suggests that, at birth, our minds are like a blank slate (tabula rasa, in Latin) upon which our experiences write a lifelong story. For nearly 130 years now, empiricism has guided psychologists in seeking knowledge about behavior and mental processes through observations governed by the rules of science. Wundt and the Structuralism of Titchener By the mid-1800s, a number of German physiologists, including Hermann von Helmholtz and Gustav Fechner (pronounced “FECK-ner”), were conducting scientific studies of the structure and function of vision, hearing, and the other sensory systems and perceptual rocesses that empiricism had identified as the channels through which human p knowledge flows. Fechner’s work was especially valuable because he realized that one could study these mental processes by observing people’s reactions to changes in sensory stimuli. By exploring, for example, how much brighter a light must become before we see it as twice as bright, Fechner discovered complex, but predictable, relationships between changes in the physical characteristics of stimuli and changes in our psychological experience of them. Fechner’s approach, which he called psychophysics, paved the way for much of the research described in the chapter on perception. As a physiologist, Wundt, too, used the methods of laboratory science to study sensory-perceptual systems, but the focus of his work was consciousness, the mental experiences created by these systems. Wundt wanted to describe the basic elements of consciousness, how they are organized, and how they relate to one another (Schultz & Schultz, 2004). For example, he developed ingenious laboratory methods to study the speed of decision making and other mental events. And in an attempt to observe conscious experience, Wundt used the technique of introspection, which means “looking inward.” After training research participants in this method, he repeatedly showed a light or made a sound and asked them to describe the sensations and feelings these stimuli created. Wundt concluded that “quality” (e.g., cold or blue) and “intensity” (e.g., brightness or loudness) are the two essential elements of any sensation and that feelings can be described in terms of pleasuredispleasure, tension-relaxation, and excitement-depression (Schultz & Schultz, 2004). In conducting this kind of research, Wundt began psychology’s transformation from the philosophy of mental processes to the science of mental processes. The World of Psychology: An Overview 13 Edward Titchener, an Englishman who had been a student of Wundt’s, used introspection in his own laboratory at Cornell University. He studied Wundt’s basic elements of consciousness, as well as images and other aspects of conscious experience that are harder to quantify (see Figure 1.4). One result was that Titchener added “clearness” as an element of sensation (Schultz & Schultz, 2004). Titchener called his approach structuralism because he was trying to define the structure of consciousness. Wundt was not alone in the scientific study of mental processes, nor was his work universally accepted. Some of his fellow German scientists, such as Hermann Ebbinghaus, believed that analyzing consciousness through introspection was not as important as exploring the capacities and limitations of mental processes such as learning and memory. Ebbinghaus’s own laboratory experiments—in which he served as the only participant—formed the basis for some of what we know about memory today. Around 1912, other German colleagues, including Max Wertheimer, Kurt Koffka, and Wolfgang Köhler, argued against Wundt’s efforts to break down human experience or consciousness into its component parts. They were called Gestalt psychologists because they pointed out that the whole (or Gestalt, in German) of conscious experience is not the same as the sum of its parts. Wertheimer noted, for example, that if a pair of lights goes on and off in just the right sequence, e experience not two flashing lights but a single light “jumping” back and forth. w You have probably seen this phi phenomenon in action on advertising signs that create the impression of a series of lights racing around a display. Movies provide another example. Imagine how boring it would be to browse slowly through the thousands of still images that are printed on a reel of film. Yet when those same images are projected onto a screen at a particular rate, they combine to create a rich, emotional experience. In other words, said the Gestaltists, consciousness should be studied as a whole, not piece by piece. Freud and Psychoanalysis While Wundt and his colleagues in Leipzig were conducting scientific research on consciousness, Sigmund Freud (1856–1939) FIGURE 1.4 A Stimulus for Introspection Look at this object and try to ignore what it is. Instead, try to describe only your conscious experience, such as redness, brightness, and roundness, and how intense and clear the sensations and images are. If you can do this, you would have been an excellent research assistant in Titchener’s laboratory. Wilhelm Wundt (1832–1920) In an early experiment on the speed of mental processes, Wundt (third from left) first measured how quickly people could respond to a light by releasing a button they had been holding down. He then measured how much longer the response took when they held down one button with each hand and had to decide—based on the color of the light—which one to release. Wundt reasoned that the additional response time reflected how long it took to perceive the color and decide which hand to move. As noted in the chapter on cognition and language, the logic behind this experiment remains a part of research on cognitive processes today. Source: The Psychology Archive—The University of Akron 14 CHAPTER 1 Introducing Psychology TRY THIS was in Vienna, Austria, beginning to explore the unconscious. As a physician, Freud ad presumed that all behavior and mental processes have physical causes somewhere in the h nervous system. He began to question that assumption in the late 1800s, however, after encountering several patients who displayed a variety of physical ailments that had no apparent physical cause. After interviewing these patients using hypnosis and other methods, Freud became convinced that the causes of these people’s physical problems were not physical. The real causes, he said, were deep-seated problems that the patients had pushed out of consciousness (Friedman & Schustack, 2003). He eventually came to believe that all behavior—from everyday slips of the tongue to severe forms of mental disorder—is motivated by psychological processes, especially by mental conflicts that occur without our awareness, at an unconscious level. For nearly fifty years, Freud developed his ideas into a body of work known as psychoanalysis, which included a theory of personality and mental disorder, as well as a set of treatment methods. Partly because they were based on a small number of medical cases, not a long series of laboratory experiments, Freud’s ideas are by no means universally accepted. Still, he was a groundbreaker whose theories have had a significant influence on psychology and many other fields. William James and Functionalism Scientific research in psychology began in North America not long after Wundt started his work in Germany. William James founded a psychology laboratory at Harvard University in the late 1870s, though it was used mainly to conduct demonstrations for his students (Schultz & Schultz, 2004). It was not until 1883 that G. Stanley Hall at Johns Hopkins University established the first psychology research laboratory in the United States. The first Canadian psychology research laboratory was established in 1889 at the University of Toronto by James Mark Baldwin, Canada’s first modern psychologist and a pioneer in research on child development. Like the Gestalt psychologists, William James rejected both Wundt’s approach and Titchener’s structuralism. He saw no point in breaking consciousness into component parts that never operate on their own. Instead, in accordance with William James’s Lab William James (1842–1910) established this psychology demonstration laboratory at Harvard University in the late 1870s. Like the Gestalt psychologists, James saw the approach used by Wundt and Titchener as a scientific dead end; he said that trying to understand consciousness by studying its components is like trying to understand a house by looking at individual bricks (James, 1884). He preferred instead to study the ways in which consciousness functions to help people adapt to their environments. The World of Psychology: An Overview 15 harles Darwin’s theory of evolution, James wanted to understand how images, C sensations, memories, and the other mental events that make up our flowing “stream of consciousness” function to help us adapt to our environment (James, 1890, 1892). This idea was consistent with an approach to psychology called functionalism, which focused on the role of consciousness in guiding people’s ability to make decisions, solve problems, and the like. James’s emphasis on the functions of mental processes encouraged North American psychologists to look not only at how those processes work to our advantage but also at how they differ from person to person. Some of these psychologists began to measure individual differences in learning, memory, and other mental processes associated with intelligence, made recommendations for improving educational practices in the schools, and even worked with teachers on programs tailored to children in need of special help (Bernstein, Kramer, & Phares, 2008). John B. Watson and Behaviorism Besides fueling James’s interest in the functions of consciousness, Darwin’s theory of evolution led other psychologists— especially those in North America after 1900—to study animals as well as humans. If all species evolved in similar ways, perhaps the behavior and mental processes of all species followed the same, or similar, laws and we can learn something about people by studying animals. Psychologists could not expect cats or rats or pigeons to introspect, so they watched what animals did when confronted with laboratory tasks such as finding the correct path through a maze. From these observations, they made inferences about the animals’ conscious experience and about the general laws of learning, memory, problem solving, and other mental processes that might apply to people as well as animals. John B. Watson, a psychology professor at Johns Hopkins University, agreed that the observable behavior of animals and humans is the most important source of scientific information for psychology. However, Watson thought it was utterly unscientific to use behavior as the basis for making inferences about consciousness, as structuralists and functionalists did—let alone about the unconscious, as Freudians did. In 1913, Watson published an article called “Psychology As the Behaviorist Views It.” In it, he argued that psychologists should ignore mental events and base psychology only on what they can actually see in overt behavior and in responses to various stimuli (Watson, 1913, 1919). Watson’s view, called behaviorism, recognized the existence of consciousness but did not consider it worth studying because it would always be private and therefore not observable by scientific methods. In fact, said Watson, preoccupation with consciousness would prevent psychology from ever being a true science. Watson believed that the most important determinant of behavior is learning and that it is through learning that animals and humans are able to adapt to their environments. He was famous for claiming that with enough control over the environment, he could create learning experiences that would turn any infant into a doctor, a lawyer, or even a criminal. American psychologist B. F. Skinner was another early champion of behaviorism. From the 1930s until his death in 1990, Skinner worked on mapping out the details f how rewards and punishments shape, maintain, and change behavior through what o he termed “operant conditioning.” Through his functional analysis of behavior, he would explain, for example, how parents and teachers can unknowingly encourage children’s tantrums by rewarding them with attention, and how a virtual addiction to gambling can result from the occasional and unpredictable rewards it brings. Many psychologists were drawn to Watson’s and Skinner’s vision of psychology as the learning-based science of observable behavior. In fact, behaviorism dominated psychological research from the 1920s through the 1960s, while the study of consciousness received less attention, especially in the United States. (“In Review: The Development of Psychology” summarizes behaviorism and the other schools of thought that have influenced psychologists in the past century.) 16 CHAPTER 1 Introducing Psychology Psychology Today Psychologists continue to study all kinds of overt behavior in humans and in animals. By the end of the 1960s, however, many had become dissatisfied with the limitations imposed by behaviorism (some, especially in Europe, had never accepted it in the first place). They grew uncomfortable about ignoring mental processes that might be important in more fully understanding behavior (e.g., Ericsson & Simon, 1994). The dawn of the computer age influenced these psychologists to think about mental activity in a new way—as information processing. Computers and rapid progress in computer-based biotechnology began to offer psychologists exciting new ways to study mental processes and the biological activity that underlies them. As shown in Figure 1.1, for example, it is now possible to literally see what is going on in the brain when, for example, a person thinks or makes decisions. Armed with ever more sophisticated research tools, psychologists today are striving to do what Watson thought was impossible: to study mental processes with precision and scientific objectivity. In fact, there are probably now as many psychologists who study cognitive and biological processes as there are who study observable behaviors. So mainstream psychology has come full circle, once again accepting consciousness—in the form of cognitive processes—as a legitimate topic for scientific research and justifying the definition of psychology as the science of behavior and mental processes (Gallagher & Sørensen, 2006; Haynes & Rees, 2005). Approaches to the Science of Psychology As you can see, the history of psychology is partly the history of the different aspects of behavior and mental processes—such as conscious experiences, unconscious conflicts, or overt actions—that have been emphasized by different groups of psychologists. Why so much variation? Put yourself in their shoes. Suppose that you are a psychologist, and you want to know why some people stop to help a sick or injured stranger and others just keep walking. Where would you start? You could look for answers in people’s brain cells and hormones, in their genetic background, in their personality traits, and in what they have learned from family, friends, and cultural traditions, to Approaches to the Science of Psychology 17 School of Thought Early Advocates Goals Methods tructuralism Edward Titchener, trained To study conscious experience and Experiments; S introspection by Wilhelm Wundt its structure Gestalt psychology Max Wertheimer To describe the organization of Observation of sensory/perceptual mental processes: “The whole is phenomena greater than the sum of its parts.” Psychoanalysis Sigmund Freud To explain personality and Study of individual cases behavior; to develop techniques for treating mental disorders Functionalism William James To study how the mind works in Naturalistic observation of animal allowing an organism to adapt and human behavior to the environment Behaviorism John B. Watson, To study only observable behavior Observation of the relationship B. F. Skinner and explain behavior through between environmental stimuli and learning principles behavioral responses in review The Development of Psychology name just a few possibilities. With so many research directions available, you’d have to decide which sources of information were most likely to explain helping. Psychologists have to make the same kinds of decisions, not only about where to focus their research but also about what kind of treatment methods to use, or what services to provide to schools, businesses, government agencies, or other clients. Their decisions are guided mainly by their overall approach to psychology—that is, by the assumptions, questions, and methods they believe will be most useful in their work. The approaches we described earlier as structuralism and functionalism are gone now, but the psychodynamic and behavioral approaches remain, along with others known as biological, evolutionary, cognitive, and humanistic approaches. Some psychologists adopt just one of these approaches, but most psychologists are eclectic. This means that they blend assumptions and methods from two or more approaches in an effort to more fully understand behavior and mental processes (e.g., Cacioppo et al., 2000). Some approaches to psychology are more influential than others these days, but we will review the main features of all of them to help you understand how they differ and how they have affected psychologists’ work over the years. The Biological Approach As its name implies, the to psychology assumes that behavior and mental processes are largely shaped by biological processes. Psychologists who take this approach study the psychological effects of hormones, genes, and the activity of the nervous system, especially the brain. So if they are studying memory, they might try to identify the changes taking place in the brain as information is stored there (Figure 7.18, in the chapter on memory, shows an example of these changes). Or if they are studying thinking, they might look for patterns of brain activity associated with, say, making quick decisions or reading a foreign language. Research discussed in nearly every chapter of this book reflects the enormous influence of the biological approach on psychology today. To help you better understand the terms and concepts used in that research, we have included an appendix on the principles of genetics and a chapter on biological aspects of psychology. The Evolutionary Approach Biological processes also figure prominently in an approach to psychology based on Charles Darwin’s book, The Origin of Species. Darwin argued that the forms of life we see today are the result of evolution—of changes in life forms that occur over many generations. He said that evolution occurs through natural selection, which promotes the survival of the fittest individuals. Most evolutionists now see natural selection operating at the level of genes, but at either level, the process is the same. Genes that result in characteristics and behaviors that are adaptive and useful in a certain environment will enable the creatures that inherited them to survive and reproduce, thereby making it more likely that those genes will be passed on to the next generation. Genes that result in characteristics that are not adaptive in that environment are not passed on to subsequent generations, because the creatures possessing them don’t survive to reproduce. So evolutionary theory says that many (but not all) of the genes we possess today are the result of natural selection. The to psychology assumes that the behavior of animals and humans today is also the result of evolution through natural selection. For example, psychologists who take this approach see cooperation as an adaptive survival strategy, aggression as a form of territory protection, and gender differences in mate-selection preferences as reflecting strategies that have been successful in previous generations. The evolutionary approach has generated a growing body of research (Buller, 2005; Buss, 2004a; Cosmides & Tooby, 2004); in later chapters, you will see how it is applied in relation to topics such as helping and altruism, mental disorders, temperament, and interpersonal attraction. evolutionary approach biological approach An approach to psychology in which behavior and behavior disorders are seen as the result of physical processes, especially those relating to the brain and to hormones and other chemicals. evolutionary approach An approach to psychology that emphasizes the inherited, adaptive aspects of behavior and mental processes. A Father’s Love Mothers are solely responsible for the care and protection of their offspring in almost all species of mammals. These species survive without male involvement in parenting, so why are some human fathers so involved in child rearing? Do evolutionary forces make fathering more adaptive for humans? Is it a matter of learning to care? Is it a combination of both? Psychologists who take an evolutionary approach study these questions and others relating to the origins of both the positive and negative aspects of human social behavior (Buss, 2004a; Wright, 1994). biological approach 18 CHAPTER 1 Introducing Psychology The Psychodynamic Approach The to psychology offers a different slant on the role of inherited instincts and other biological forces in human behavior. Rooted in Freud’s psychoanalysis, this approach assumes that our behavior and mental processes reflect constant, and mostly unconscious, psychological struggles within us (see Figure 1.5). Usually, these struggles involve conflict between the impulse to satisfy instincts (such as for food, sex, or aggression) and the need to follow the rules of civilized society. So psychologists taking the psychodynamic approach might see aggression, for example, as a case of primitive urges overcoming a person’s defenses against expressing those urges. They would see anxiety, depression, or other disorders as overt signs of inner turmoil. Freud’s original theories are not as influential today as they once were (Mischel, 2004a), but you will encounter modern versions of the psychodynamic approach in other chapters when we discuss theories of personality, psychological disorders, and psychotherapy. The Behavioral Approach The assumptions of the to psychology contrast sharply with those of the psychodynamic, biological, and evolutionary approaches. As founded by John Watson, behaviorism characterizes behavior as primarily the result of learning. From a strict behaviorist point of view, biological, genetic, and evolutionary factors simply provide “raw material,” which is then shaped by learning experiences into what we see in each individual’s actions. So strict behaviorists seek to understand all behavior—whether it is aggression or drug abuse, shyness or sociability, confidence or anxiety—by looking at the individual’s learning history, especially the patterns of reward and punishment the person has experienced. They also believe that people can change all sorts of problematic behaviors, from overeating to criminality, by unlearning old habits and developing new ones. Recall, though, that behaviorism was criticized precisely because it ignored everything but observable behavior. That criticism has had an impact on the many behaviorists who now apply their learning-based approach in an effort to understand thoughts, or cognitions, as well as observable behavior. Those who take this cognitivebehavioral, or social-cognitive, approach explore how learning affects the development psychodynamic approach A view developed by Freud that emphasizes the interplay of unconscious mental processes in determining human thought, feelings, and behavior. behavioral approach An approach to psychology emphasizing that human behavior is determined mainly by what a person has learned, especially from rewards and punishments. behavioral approach psychodynamic approach Approaches to the Science of Psychology 19 FIGURE 1.5 What Do You See? Take a moment to jot down what you see in these clouds. According to the psychodynamic approach to psychology, what we see in cloud formations and other vague patterns reflects unconscious wishes, impulses, fears, and other mental processes. In the personality chapter, we discuss the value of personality tests based on this assumption. TRY THIS of thoughts, attitudes, and beliefs and, in turn, how these learned cognitive patterns affect overt behavior. The Cognitive Approach The growth of the cognitive-behavioral perspective reflects the influence of a broader cognitive approach to psychology. The focuses on how we take in, mentally represent, and store information; how we perceive and process that information; and how cognitive processes are related to our behavior. In other words, psychologists who take the cognitive approach study the rapid series of hidden mental events—including those taking place outside of awareness—that accompany the behavior they can see. Here is how a psychologist might use the cognitive approach to describe the information processing that occurs during an aggressive incident outside a movie theater: The aggressive person (1) perceives that someone has cut into the ticket line, (2) recalls information stored in memory about appropriate social behavior, (3) decides that the other person’s action was inappropriate, (4) labels the person as rude and inconsiderate, (5) considers possible responses and their likely consequences, (6) decides that shoving the person is the best response, and (7) executes that response. Psychologists who take a cognitive approach focus on these and other mental processes to understand many kinds of individual and social behaviors, from decision making and problem solving to interpersonal attraction and intelligence, to name but a few. In the situation we just described, for example, the person’s aggression would be een as the result of poor problem solving, because there were probably several better s ways to deal with the problem of line-cutting. The cognitive approach is especially important in the field of cognitive science, in which researchers from psychology, computer science, biology, engineering, linguistics, and philosophy study intelligent systems in humans and computers. Together, they are trying to discover the building blocks of cognition and to determine how these components produce complex behaviors such as remembering a fact, naming an object, writing a word, or making a decision. The Humanistic Approach Mental events play a different role in the to psychology (also known as the phenomenological approach). Psychologists who favor the humanistic perspective see behavior as determined primarily by each person’s capacity to choose how to think and act. They don’t see these choices as driven by instincts, humanistic approach cognitive approach A way of looking at human behavior that emphasizes research on how the brain takes in information, creates perceptions, forms and retrieves memories, processes information, and generates integrated patterns of action. humanistic approach An approach to psychology that views behavior as controlled by the decisions that people make about their lives based on their perceptions of the world. cognitive approach Why Is He So Aggressive? Psychologists who take the cognitivebehavioral approach suggest that children’s aggressiveness is largely learned. They say this learning occurs partly through seeing family and friends acting aggressively, but also through hearing people talk about aggression as the only way to deal with threats, disagreements, and other conflict situations (e.g., Gifford-Smith et al., 2005). 20 CHAPTER 1 Introducing Psychology biological processes, or rewards and punishments, but by each individual’s unique perceptions of the world. So if you see the world as a friendly place, you are likely to be optimistic and secure. If you perceive it as full of hostile, threatening people, you will probably be defensive and fearful. Like their cognitively oriented colleagues, psychologists who choose the humanistic approach would see aggression in a theater line as stemming from a perception that aggression is justified. But where the cognitive approach leads psychologists to search for laws governing all people’s thoughts and actions, humanistic psychologists try to understand how each individual’s unique experiences guide that person’s thoughts and actions. In fact, many proponents of the humanistic approach say that behavior and mental processes can be fully understood only by understanding the perceptions and feelings of individuals. Humanistic psychologists also believe that people are essentially good, that they are in control of themselves, and that they have an innate tendency to grow toward their highest potential. Indeed, some of the roots of today’s growing emphasis on positive psychology can be found in the writings of humanistic psychologists such as Abraham Maslow and Carl Rogers (Peterson & Seligman, 2004; Strümpfer, 2005). The humanistic approach began to attract attention in North America in the 1940s through the writings of Rogers (1902–1987), a psychologist who had been trained in, but later rejected, the psychodynamic approach. We describe his views on personality and his psychotherapy methods in the chapters on personality and the treatment of psychological disorders. Maslow (1908–1970) also shaped and promoted the humanistic approach through his famous hierarchy-of-needs theory of motivation, which we describe in the chapters on motivation and emotion and personality. Today, however, the impact of the humanistic approach to psychology is limited, mainly because many psychologists find humanistic concepts and predictions too vague to be expressed and tested scientifically. (For a summary of the approaches we have discussed, see “In Review: Approaches to the Science of Psychology.”) Human Diversity and Psychology