PREFACExxiieven though this meant removing substantial amounts of text dearly cherished by theauthors. Chapter 1 adds new research on the dangers of using a cell phone while driv-ing,and the section onrelationships between applied and basic research hasbeenupdated to coverrecentdevelopments in thepushtotranslatebasicfindings intoappli-cations at NIH.Chapter 2contains new data in Table2-1 and new discussion that mediaviolence is a threat to public health, and the chapter now discusses the attitudes ofvoters toward the appearance of presidential candidates on late-night comedy showsChapter 3 has a new and more interesting example, relating belief in God to aggres-sion,which illustrates the importanceof interactions.Chapter 4 has additional descrip-tion of theIRBprocess and problems associated with perceived unfairness.Chapter5has a new sample journal article and also refers to a recent list of tips for authors ofjournal articles.In Chapter6wereplaceda1952 chapter-opening example with a 2007example, even though the author really liked the old example. In Chapter 7 the discus-sion of perceptual defense was replaced bya discussion of explicit awareness research.Chapter8 has a newdiscussionof cognitivecontrol.Chapter9 has anew discussionof changing-criterion design as used in therapy.Chapter 10 has new examples of flash-bulb memoryand the savingsmethod.Chapter 11 now includesmention of recentneuroimagingresearch.Chapter 12also adds currentwork on brain imagingas well asrecentworkonmotivationandintellectualperformance.Chapter13includesnewresearch on social contagion of memory, obedience, and implicit attitudes and behavior.Chapter14 adds new work that challenges the classical animal model of crowding andalso research that improves a measure of density in a train car. Chapter 15 adds a newstudy on dynamic visual acuity and a brief discussion on the use of models to explainmentalworkload.Pleasecontinuetolettheauthorsknowhowyouandyourstudentsreact to these substantial changes.ACKNOWLEDGMENTSIt takes many more peoplethan authorsto createa text that has endured for nineeditions,and the authors are pleased to acknowledge with gratitudethe assistance ofnumerous others. Our greatest debt is to the readers of previous editions who continueto offer many useful comments. Without their helpful suggestions, this new editionwould not exist.Mila Sugovic provided excellent editorial help, especially with the art work inChapters2,7,and 9,andKeith Lyle and JaneMcConnell provided valuable assistancein manuscriptpreparation and proofreading among other things, and we thank themall.Wealso thankErik Evans,Rebecca Rosenberg,and Pat Waldo at CengageandCarol O'Connell at Graphic World Publishing Services for their substantial efforts guid-ing our book through theproduction process.We would like to thank thefollowing reviewers, who provided feedback to helpus with this revision: Jeffrey M. Zacks, Washington University; Sandra Sego, AmericanInternational College;Hallie Stephens, Southeastern Oklahoma State University;andPaul Thuras, St. Mary's University of Minnesota
even though this meant removing substantial amounts of text dearly cherished by the authors. Chapter 1 adds new research on the dangers of using a cell phone while driving, and the section on relationships between applied and basic research has been updated to cover recent developments in the push to translate basic fi ndings into applications at NIH. Chapter 2 contains new data in Table 2-1 and new discussion that media violence is a threat to public health, and the chapter now discusses the attitudes of voters toward the appearance of presidential candidates on late-night comedy shows. Chapter 3 has a new and more interesting example, relating belief in God to aggression, which illustrates the importance of interactions. Chapter 4 has additional description of the IRB process and problems associated with perceived unfairness. Chapter 5 has a new sample journal article and also refers to a recent list of tips for authors of journal articles. In Chapter 6 we replaced a 1952 chapter-opening example with a 2007 example, even though the author really liked the old example. In Chapter 7 the discussion of perceptual defense was replaced by a discussion of explicit awareness research. Chapter 8 has a new discussion of cognitive control. Chapter 9 has a new discussion of changing-criterion design as used in therapy. Chapter 10 has new examples of fl ashbulb memory and the savings method. Chapter 11 now includes mention of recent neuroimaging research. Chapter 12 also adds current work on brain imaging as well as recent work on motivation and intellectual performance. Chapter 13 includes new research on social contagion of memory, obedience, and implicit attitudes and behavior. Chapter 14 adds new work that challenges the classical animal model of crowding and also research that improves a measure of density in a train car. Chapter 15 adds a new study on dynamic visual acuity and a brief discussion on the use of models to explain mental workload. Please continue to let the authors know how you and your students react to these substantial changes. ▼ ACKNOWLEDGMENTS It takes many more people than authors to create a text that has endured for nine editions, and the authors are pleased to acknowledge with gratitude the assistance of numerous others. Our greatest debt is to the readers of previous editions who continue to offer many useful comments. Without their helpful suggestions, this new edition would not exist. Mila Sugovic provided excellent editorial help, especially with the art work in Chapters 2, 7, and 9, and Keith Lyle and Jane McConnell provided valuable assistance in manuscript preparation and proofreading among other things, and we thank them all. We also thank Erik Evans, Rebecca Rosenberg, and Pat Waldo at Cengage and Carol O’Connell at Graphic World Publishing Services for their substantial efforts guiding our book through the production process. We would like to thank the following reviewers, who provided feedback to help us with this revision: Jeffrey M. Zacks, Washington University; Sandra Sego, American International College; Hallie Stephens, Southeastern Oklahoma State University; and Paul Thuras, St. Mary’s University of Minnesota. PREFACE xxiii 59533_01_fm_pi-xxiv.indd xxiii 9533_01_fm_pi-xxiv.indd xxiii 3/6/08 7:06:51 PM /6/08 7:06:51 PM
ORGANIZATIONOETHEBOOKExperimental Topics1012Choosing the dependent variableConfounding1Converging operationsCounterbalancingDemand characteristicsEthical issuesExperimental control/extraneous variablesField researchGeneralizationofresultsInteraction effectsMeasurement scalesOperational definitionQuasi-experimentsRegressionartifactsReliability of measures Scale attenuationSelection of dependent variableSmall-n designVerbal reportWithin-and between-subjects designs
ORGANIZATION OF THE BOOK Experimental Topics 6 7 8 9 10 11 12 13 14 15 Choosing the dependent variable X Confounding X Converging operations X Counterbalancing X Demand characteristics X Ethical issues X Experimental control/ extraneous variables X X Field research X X Generalization of results X X Interaction effects X X Measurement scales X Operational defi nition X X Quasi-experiments X Regression artifacts X Reliability of measures X X Scale attenuation X Selection of dependent variable X X X Small-n design X X X Verbal report X X Within- and between-subjects designs X 59533_01_fm_pi-xxiv.indd xxiv 9533_01_fm_pi-xxiv.indd xxiv 3/6/08 7:06:51 PM /6/08 7:06:51 PM
PARTFUNDAMENTALSOFRESEARCHONEExplanation in Scientific PsychologyTWOResearchTechniques:Observation and CorrelationTHREEResearchTechniques:ExperimentsFOUREthics in Psychological ResearchFIVEHowto Read and Write Research Reports
1 PART 1 FUNDAMENTALS OF RESEARCH ONE Explanation in Scientifi c Psychology TWO Research Techniques: Observation and Correlation THREE Research Techniques: Experiments FOUR Ethics in Psychological Research FIVE How to Read and Write Research Reports 1 59533_02_ch01_p001-023.indd 1 9533_02_ch01_p001-023.indd 1 3/4/08 11:47:07 PM /4/08 11:47:07 PM
CHAPTEREXPLANATIONIN SCIENTIEICPSYCHOLOGYMAKINGSENSEOFTHEWORLDSocial LoafingCuriosity:TheWellspringof ScienceSOURCES OF KNOWLEDGEFixation of BeliefTHENATUREOFTHESCIENTIFICEXPLANATIONWhat Is a Theory?InductionandDeductionFrom Theory to HypothesisEvaluating TheoriesInterveningVariablesFoxes and Hedgehogs Roaming through Psychological TheoryTHESCIENCEOFPSYCHOLOGYPsychology and the Real WorldSUMMARYKEYTERMSDISCUSSION QUESTIONSwWEBCONNECTIONS
3 CHAPTER 1 EXPLANATION IN SCIENTIFIC PSYCHOLOGY MAKING SENSE OF THE WORLD Social Loafi ng Curiosity: The Wellspring of Science SOURCES OF KNOWLEDGE Fixation of Belief THE NATURE OF THE SCIENTIFIC EXPLANATION What Is a Theory? Induction and Deduction From Theory to Hypothesis Evaluating Theories Intervening Variables Foxes and Hedgehogs Roaming through Psychological Theory THE SCIENCE OF PSYCHOLOGY Psychology and the Real World SUMMARY KEY TERMS DISCUSSION QUESTIONS WEB CONNECTIONS 59533_02_ch01_p001-023.indd 3 9533_02_ch01_p001-023.indd 3 3/4/08 11:47:12 PM /4/08 11:47:12 PM
Askany scientistwhathe conceivesthescientific methodtobe,andhewilladoptanexpressionthatisatoncesolemnandshifty-eyed;solemn,becausehefeels he oughtto declare an opinion,shifty-eyed becausehe is wonderinghow to conceal the fact that he has no opinion to declare. If taunted he wouldprobably mumble something about"Induction"and"Establishing the Laws ofNature,"but if anyoneworking inalaboratoryprofessedtobetryingtoestab-lishLawsofNaturebyinduction,weshouldbegintothinkhewasoverdueforleave.(P.B.MEDAWAR)The goal of scientific psychology is to understand why people think and act as theydo.In contrast to nonscientists,who rely on informal and secondary sources ofknowledge,psychologists use a variety of well-developed techniques to gather informationand develop theoretical explanations.As one example of this scientific approachtounderstanding, consider the following case study of the research process.MAKINGSENSEOETHEWORLDSocial LoafingA common observationoneyouprobablyhavemadeyourself on manyoccasions-is thatpeople working in a group often seemto"slack off in their effort.Manypeoplein groups seem willing to let a few do the work.Bibb Latane, a social psychologist,noticed this tendency and decided to study it experimentally. Initially, Latane exam-ined the research literaturefor evidence of this phenomenon of peopleworking lesshard in groups,which he named social loafing.One of the earliest studies of socialloafing was conducted by a French agricultural engineer (Ringelmann, 1913; Kravitz &Martin, 1980) who asked people to pull on a rope as hard as they could. The subjectspulled by themselves or with one, two, or seven others. A sensitive gauge was used tomeasurehowhard theypulled the rope.If people exert the same amount of effort ingroups as when alone, then the group performance should be the sum of the effortsof all individuals.Ringelmann discovered that groups of two pulled at only 95 percentof their capacity, and groups of three and eight sank to 85 percent and 49 percent,respectively. So, it is probably not just our imaginations when we notice others (andourselves?)seeming to put forth less effort when working in groups:Ringelmann'sresearch provides us with a good example of social loafing.Lataneand hiscolleagues went on toperforma systematic seriesofexperimentsonthephenomenon of social loafing(Latane,1981;Latane,Williams,&Harkins,1979).They firstshowed that the phenomenon could be obtained in other experimental situations besidesthat of rope pulling.They also demonstrated that social loafing occurs in several differentcultures (Gabrenya, Latane, & Wang, 1983) and even holds for young children Thus, socialloafing seemstobeapervasivecharacteristicof working ingroups
The goal of scientifi c psychology is to understand why people think and act as they do. In contrast to nonscientists, who rely on informal and secondary sources of knowledge, psychologists use a variety of well-developed techniques to gather information and develop theoretical explanations. As one example of this scientifi c approach to understanding, consider the following case study of the research process. ▼ MAKING SENSE OF THE WORLD Social Loafi ng A common observation—one you probably have made yourself on many occasions— is that people working in a group often seem to “slack off” in their effort. Many people in groups seem willing to let a few do the work. Bibb Latané, a social psychologist, noticed this tendency and decided to study it experimentally. Initially, Latané examined the research literature for evidence of this phenomenon of people working less hard in groups, which he named social loafi ng. One of the earliest studies of social loafi ng was conducted by a French agricultural engineer (Ringelmann, 1913; Kravitz & Martin, 1986) who asked people to pull on a rope as hard as they could. The subjects pulled by themselves or with one, two, or seven others. A sensitive gauge was used to measure how hard they pulled the rope. If people exert the same amount of effort in groups as when alone, then the group performance should be the sum of the efforts of all individuals. Ringelmann discovered that groups of two pulled at only 95 percent of their capacity, and groups of three and eight sank to 85 percent and 49 percent, respectively. So, it is probably not just our imaginations when we notice others (and ourselves?) seeming to put forth less effort when working in groups: Ringelmann’s research provides us with a good example of social loafi ng. Latané and his colleagues went on to perform a systematic series of experiments on the phenomenon of social loafi ng (Latané, 1981; Latané, Williams, & Harkins, 1979). They fi rst showed that the phenomenon could be obtained in other experimental situations besides that of rope pulling. They also demonstrated that social loafi ng occurs in several different cultures (Gabrenya, Latané, & Wang, 1983) and even holds for young children. Thus, social loafi ng seems to be a pervasive characteristic of working in groups. Ask any scientist what he conceives the scientifi c method to be, and he will adopt an expression that is at once solemn and shifty-eyed; solemn, because he feels he ought to declare an opinion, shifty-eyed because he is wondering how to conceal the fact that he has no opinion to declare. If taunted he would probably mumble something about “Induction” and “Establishing the Laws of Nature,” but if anyone working in a laboratory professed to be trying to establish Laws of Nature by induction, we should begin to think he was overdue for leave. (P. B. MEDAWAR) 59533_02_ch01_p001-023.indd 4 9533_02_ch01_p001-023.indd 4 3/4/08 11:47:13 PM /4/08 11:47:13 PM