Experimental Psychology by Myers 7th edition PDF

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Hello! This is a free pdf of Myers "Experimental Psychology" book that has helped me thru the course. Her descriptions and explanations of concepts are useful when it comes to studying the technicalities of experimenting. I hope this could help you :)...

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Licensed to: CengageBrain User

Licensed to: CengageBrain User

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Experimental Psychology, Seventh Edition Anne Myers, Christine H. Hansen Publisher/Executive Editor: Linda Schreiber-Ganster Acquisitions Editor: Timothy Matray Assistant Editor: Phillip Hovanessian Media Editor: Layren Keyes Marketing Coordinator: Anna Andersen

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Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

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CHAPTER

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Experimental Psychology and the Scientific Method

The Need for Scientific Methodology

Scientific Explanation in Psychological Science

Nonscientific Sources of Data Nonscientific Inference

Identifying Antecedent Conditions Comparing Treatment Conditions The Psychology Experiment Establishing Cause and Effect Necessary versus Sufficient Conditions

The Characteristics of Modern Science The Scientific Mentality Gathering Empirical Data Seeking General Principles Good Thinking Self-Correction Publicizing Results Replication

The Objectives of Psychological Science The Scientific Method: Tools of Psychological Science

From Pseudoscience to Psychological Science The Organization of the Text SUMMARY KEY TERMS REVIEW AND STUDY QUESTIONS CRITICAL THINKING EXERCISE ONLINE RESOURCES

Observation Measurement Experimentation

3 Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

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PART 1 • Introduction

C H APT E R OBJ E C T IV E S ●

Understand why we rely on scientific methods rather than common sense to explain behavior

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Learn the principles of the scientific method

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Learn the basic tools of psychological research

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Understand how “cause and effect” is established by experimentation

Psychology is the science of behavior. As psychologists, we take a scientific approach to understanding behavior, and our knowledge about psychological processes is based on scientific evidence accumulated through research. As scientists, we rely on scientific methods when we conduct psychological research, such as specifying the conditions under which we make our observations, observing in a systematic or orderly way, and accepting or rejecting alternative explanations of behaviors on the basis of what we observe. In short, research about the psychological processes underlying behavior is known as psychological science. The word science comes from the Latin word scientia, which simply means knowledge. As the word is used today, however, it has two meanings— content and process. The content of science is what we know, such as the facts we learn in our psychology or chemistry courses. But science is also a process—that is, an activity that includes the systematic ways in which we go about gathering data, noting relationships, and offering explanations. Explaining the process of psychological science is the principal aim of this text. In the chapters that follow, we will examine some of the basic tactics used in psychological research. We will study methodology, the scientific techniques used to collect and evaluate psychological data (the facts and figures gathered in research studies). All areas of psychology rely on scientific research methods. Researchers investigating perception, for example, collect data in formal laboratory experiments designed to provide the most precise information. Psychologists interested in understanding attitudes and social behaviors sometimes gather data under controlled laboratory conditions; at other times, they conduct surveys in the community or observe and record people’s behavior in natural settings. Psychologists studying human development might observe young children’s reactions under different conditions in the laboratory or in Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

Licensed to: CengageBrain User CHAPTER 1 • Experimental Psychology and the Scientific Method

5

real-world settings. Clinical psychologists may collect data by administering psychological tests or by observing personality functioning during sessions with patients. Whether the data come from laboratory experiments, realworld settings, or therapy sessions, all psychologists use scientific criteria to evaluate their data.

THE NEED FOR SCIENTIFIC METHODOLOGY In our daily lives, we all collect and use psychological data to understand the behavior of others and to guide our own behavior. When you notice that your roommate is in a bad mood, you don’t ask for a favor. You dress up when you are going for a job interview because first impressions are important. You don’t invite John and Evan to the same party because they don’t like each other. You can probably think of many more examples of situations in which you used psychological data to predict the behavior of others and to guide your own behavior. The kind of everyday, nonscientific data gathering that shapes our expectations and beliefs and directs our behavior toward others has been called commonsense psychology (Heider, 1958). Commonsense psychology seems to work well enough for us most of the time. At other times, though, nonscientific data gathering can leave us up in the air. Suppose, for example, that your significant other has just announced that she has been accepted for a summer program at the Sorbonne in Paris. Should you be worried? Some of the nonscientific data you gather about absent partners is reassuring (“absence makes the heart grow fonder”), but some is not (“out of sight, out of mind”). Most of your data seems to support the former conclusion, so you see her off at the airport in good spirits. On the drive home, you remember all the stories you have heard about Paris nightlife and sexy Parisian men…. Without knowing which outcome is really more probable, you are likely to spend an anxious summer. An understanding of the characteristics and limitations of commonsense psychology might not help with dilemmas like this one, but it may help you become a better psychological scientist—if only because it clearly demonstrates the need for a more scientific approach to understanding and predicting behavior. As commonsense psychologists, we find that our ability to gather data in a systematic and impartial way is constrained by two very important factors: the sources of psychological information and our inferential strategies. Commonsense beliefs about behavior are derived from data we collect from our own experience and what we have learned from others. The data we collect in our everyday lives have been generated from a very small sample of behaviors, and the conclusions we draw from them are subject to a number of inherent tendencies, or biases, that limit their accuracy and usefulness. Often, the sources of our commonsense beliefs about behavior can be unreliable, and the explanations and predictions that we derive from them are likely to Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

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PART 1 • Introduction

be imperfect. Do birds of a feather flock together? Or do opposites attract? Our language is filled with these kinds of conflicting, commonsense adages, and commonsense psychology does not help us know which one to use to predict behavior in any single instance.

Nonscientific Sources of Data Very often, the data we gather as commonsense psychologists come from sources that seem credible and trustworthy—friends and relatives, people in authority, people we admire, reports from the media, books we have read, and so forth—but, actually, these sources are not always very good ones for obtaining valid information about behavior. Nevertheless, psychological information, particularly when it is offered by people we like, respect, or admire, is typically accepted without question. These beliefs tend to become stable because we rarely, if ever, test them. Once we believe we know something, we tend to overlook instances that might disconfirm our beliefs, and we seek, instead, confirmatory instances of behavior. This has been termed the confirmation bias. If you believe that the full moon brings out psychotic behavior (the word lunacy comes from the Latin word for “moon”), you will notice and remember instances when people acted abnormally while the moon was full, and you will ignore the many, many more instances in which no unusual behavior occurred. It is also unlikely that anyone can completely avoid assimilating some myths, superstitions, and pop psychology explanations for behavior. Do you believe in the power of crystals? (Some people believe that wearing amethyst will increase their intuition and that clear quartz will build inner strength.) Do you ever read your horoscope? Do you knock on wood to avoid bad luck? Do you feel a bit anxious on Friday the 13th? Interestingly, only the latter superstition—fear of Friday the 13th—has produced any supportive scientific documentation (see Box 1.1). Research has shown that we are more likely to believe information if it comes from certain kinds of individuals: People who are popular, attractive, high in status, seemingly expert, or who appear highly confident are more powerful sources of information than others are. But other people are not our sole source of data about psychological processes. We gather a lot of information about behavior from our own observations and interactions with others and the conclusions we draw from them. Children learn very early that their smiles and vocalizations are rewarded and that touching a lit candle or a hot stove can have very negative consequences. We learn to predict consequences and direct our behavior toward desired goals. Frequently, we use our beliefs and feelings about how things operate to explain behavior—our own as well as that of others. Researchers have discovered that we are not always privy to our own decision-making processes (Nisbett & Wilson, 1977). North, Hargreaves, and McKendrick (1999) conducted an interesting experiment that demonstrates this inability. In their experiment, French or German music was played on alternate days from a supermarket display featuring two French and German wines of similar price and sweetness. As predicted, on days that Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

Licensed to: CengageBrain User CHAPTER 1 • Experimental Psychology and the Scientific Method

The Power of Negative Thinking

Friday the 13th has a mythical history of being unlucky, and if Friday falls on the 13th of the month, the superstition often comes to mind (or someone reminds us!). Do you feel a moment of anxiety when you realize it’s Friday the 13th? Have you ever wondered whether it is really unlucky? Apparently it is, but probably not because of any dark and powerful, unseen force that exerts its will upon us. A study conducted in West Sussex in Great Britain and reported in the British Medical Journal (Scanlon, Luben, Scanlon, & Singleton, 1993) found that Friday the 13th did appear to be an unlucky day for drivers. When researchers compared each Friday the 13th with each Friday the 6th since 1989, looking at the number of emergency room visits from automobile accidents, more accident victims (as many as 52% more) were treated on Friday the 13th even though fewer cars were driven that day. According to the researchers, the higher accident rate for Friday the 13th was probably caused by increased trepidation about the date: Anxiety caused reduced attention to driving, and more accidents occurred. Whether their

reason is the correct one or not, it makes sense to be extra cautious if you are driving that day because other drivers might be more anxious and accidentprone than usual.

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B O X 1.1

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F IG U R E

1.1 Oh no—it’s Friday the 13th!

French music was being played, the French wine outsold the German wine; whereas German wine outsold French wine on days that German music was played (both by margins of about 3:1). Clearly, the music had an influence on purchases. When queried about the reasons for their choices, however, only 1 out of 44 people mentioned the music. Even when asked specifically whether they felt the music might have influenced their choice, only 6 out of 44 said that it might have. We are often unaware of factors that influence our attitudes and behavior. For example, when we uncritically accept information from an attractive source, we are unlikely to be aware of what actually persuaded us. If someone were to ask us, we would probably believe that the information must have been extremely persuasive. We would be unlikely to realize that we were really persuaded because the person who communicated the information was highly attractive. We frequently use data from our own experiences to come up with commonsense assumptions about cause and effect—but, if we were to rely only on commonsense psychology, we would frequently be wrong. The inferential strategies we use when we process data are sometimes too simple to be completely accurate. Let’s look at a few areas in which the commonsense psychologist is likely to make errors. Copyright 2011 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.

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F IG U R E

1.2

An expert source like Einstein would be highly persuasive.

Nonscientific Inference One of the first and most important kinds of data we collect about others comes in the form of traits we assign to them. All commonsense psychologists are trait theorists—at least when it comes to explaining the behavior of others. When we understand other people’s behavior, there is a strong bias to overlook situational data in favor of data that substantiate trait explanations (Gilbert, 1995; Ross & Nisbett, 1991). When we notice that Stacy is sporting another new designer outfit, we conclude that she is vain about her appearance and spends money frivolously. We tend to miss or ignore important information about the situation (for instance, that Stacy’s mother designs for the manufacturer and gets Stacy’s clothes for almost nothing). Our ability to make accurate predict...