CHAPTERIEXPLANATIONINSCIENTIFICPSYCHOLOGYLatane has related this work to a more general theory of human social behavior(Latane, 1981).The evidence from the experimental studies points to diffusion ofresponsibilityasapossiblereasonforsocial loafing.Peopleworkingbythemselvesthink they are responsible for completing the task; when they work in groups, how-ever, this feeling of responsibility diffuses to others. The same idea accounts for be-havior in other group situations: If one of your professors asks a question in a classcontaining only two other people, you would probably feel responsible for trying toanswer. However, if there were two hundred other people in the class, you would likelyfeel much less responsibleforanswering.Similarly,people aremore likelytohelp inan emergencywhen theyfeel theburden of responsibility than when thereare severalothersaboutwhocouldhelpOne possible benefit of such basic research into a phenomenon is that the findingsmay be applied later to solve some practical problem. A great problem in American so-ciety is the difficulty of keeping worker productivity high. Although social loafing is, atbest, only one factor involved in this complicated issue, Marriott (1949) showed that fac-tory workers working in large groups produce less per individual than do those workingin small groups: Thus, basic research that would show a way to overcome the problemof social loafing may be of great practical import. In fact, Williams, Harkins, and Latane(1981) found conditions that eliminated the effect of social loafing.When individual per-formance (rather than just performance of the entire group) could be monitored withinthe group situation, the individuals worked just as hard as they did when they workedalone. Certainly more research must be done, but it may be that simply measuring indi-vidual performance in group situations could help eliminate social loafing and increaseproductivity.Theproposed solution may seem simple, but in many jobs only group per-formance is measured and individual performance is ignored.We havediscussed Latane's studies of social loafing as an exampleof psychologicalresearch to illustrate how an interesting problem can be brought into a laboratory set-ting and studied in a controlled manner.The experiments performed will, when care-fully conducted,promote a better understanding of the phenomenon of interest thanwill simpleobservationofeventsandreflectionaboutthem.Thisbookislargelyaboutthe proper conduct of such experimental studies-how to develop hypotheses, arrangeexperimental conditions to test the hypotheses, collect observations (data) within anexperiment, and then analyze and interpret the data collected. In short, in this book wetry to cover the fundamentals of scientific inquiry as applied to psychology.Before examining the specifics of research, we discuss some general issues in theremainder of this chapter.The research on social loafing is used to illustrate severalaspects of psychological science-its purposes, its sources, and its nature.Curiosity:TheWellspringofScienceA scientist wants to discover how and why things work. In this desire, he or she is notdifferent from a child or anyone else who is curious about the world we inhabit. Thecasualobservermaynotfeelterriblyfrustratedifsomeobservation(forexample,thatwater always goes down a sink drain counterclockwise or that individual effort in agroup is low)cannot be explained.However,the professional scientist has a strongdesire to pursue an observation until an explanation is at hand or a problem is solved.It isnot so muchthat scientists are more curiousthanotherpeople as it is that they
CHAPTER 1 EXPLANATION IN SCIENTIFIC PSYCHOLOGY 5 Latané has related this work to a more general theory of human social behavior (Latané, 1981). The evidence from the experimental studies points to diffusion of responsibility as a possible reason for social loafi ng. People working by themselves think they are responsible for completing the task; when they work in groups, however, this feeling of responsibility diffuses to others. The same idea accounts for behavior in other group situations: If one of your professors asks a question in a class containing only two other people, you would probably feel responsible for trying to answer. However, if there were two hundred other people in the class, you would likely feel much less responsible for answering. Similarly, people are more likely to help in an emergency when they feel the burden of responsibility than when there are several others about who could help. One possible benefi t of such basic research into a phenomenon is that the fi ndings may be applied later to solve some practical problem. A great problem in American society is the diffi culty of keeping worker productivity high. Although social loafi ng is, at best, only one factor involved in this complicated issue, Marriott (1949) showed that factory workers working in large groups produce less per individual than do those working in small groups. Thus, basic research that would show a way to overcome the problem of social loafi ng may be of great practical import. In fact, Williams, Harkins, and Latané (1981) found conditions that eliminated the effect of social loafi ng. When individual performance (rather than just performance of the entire group) could be monitored within the group situation, the individuals worked just as hard as they did when they worked alone. Certainly more research must be done, but it may be that simply measuring individual performance in group situations could help eliminate social loafi ng and increase productivity. The proposed solution may seem simple, but in many jobs only group performance is measured and individual performance is ignored. We have discussed Latané’s studies of social loafi ng as an example of psychological research to illustrate how an interesting problem can be brought into a laboratory setting and studied in a controlled manner. The experiments performed will, when carefully conducted, promote a better understanding of the phenomenon of interest than will simple observation of events and refl ection about them. This book is largely about the proper conduct of such experimental studies—how to develop hypothe ses, arrange experimental conditions to test the hypotheses, collect observations (data) within an experiment, and then analyze and interpret the data collected. In short, in this book we try to cover the fundamentals of scientifi c inquiry as applied to psychology. Before examining the specifi cs of research, we discuss some general issues in the remainder of this chapter. The research on social loafi ng is used to illustrate several aspects of psychological science—its purposes, its sources, and its nature. Curiosity: The Wellspring of Science A scientist wants to discover how and why things work. In this desire, he or she is not different from a child or anyone else who is curious about the world we inhabit. The casual observer may not feel terribly frustrated if some observation (for example, that water always goes down a sink drain counterclockwise or that individual effort in a group is low) cannot be explained. However, the professional scientist has a strong desire to pursue an observation until an explanation is at hand or a problem is solved. It is not so much that scientists are more curious than other people as it is that they 59533_02_ch01_p001-023.indd 5 9533_02_ch01_p001-023.indd 5 3/4/08 11:47:13 PM /4/08 11:47:13 PM
6PARTIFUNDAMENTALSOFRESEARCHare willing to go to much greater lengths to satisfy their curiosity than are nonscien-tists. This unwillingness to tolerate unanswered questions and unsolved problemshas led scienceto develop several techniques for obtainingrelief from curiosity.It isthecareful application of thesetechniques thatdistinguishes scientific curiosity fromeveryday curiosity.The common denominatorfor many of these scientifictechniques is skepticism.Skepticism is the philosophical belief that the truth of all knowledge is questionable.Therefore, all inquiry must be accompanied by reasonable doubt.No scientificfact canbeknown with 100 percent certainty.For example,bridge engineering is apracticaldiscipline derived from a scientific foundation in such fields as physics and metallurgy.Most people, when they drive a car across a bridge, do not actively consider that thebridge might collapse. It is a known fact that well-maintained bridges are safe. Yet inthe summerof2007,abridgeinMinneapolis-St.Paul,Minnesota,collapsed.Thiseventwill lead to further research, to result in safer bridges being built. Many of the tools,such as statistics, discussed in this text allow the skeptical scientist to measure reason-abledoubt.Of what use is scientific curiosity? What purpose does it serve? We have stated thatpsychologists try to determine why people think and act as they do. Let us explorewhat this means in more detail.SOURCESOFKNOWLEDGEFixationof BeliefThe scientific method is a valid way to acquireknowledge about the world around us.What characteristics of the scientific approach make it a desirable way to learn aboutand arrive at beliefs about the nature of things? Perhaps the best way to answer thisquestion is to contrast science with other modes of fixing belief, since science is onlyonewayinwhichbeliefsareformed.More than one hundred years ago, the American philosopher Charles SandersPeirce (1877) compared the scientific way of knowing with three other methods ofdeveloping beliefs.He called these the authority,tenacity,anda priori methodsAccording to Peirce, the simplest way of fixing belief is to take someone else's wordon faith. A trusted authority tells you what is true and what is false.Young childrenbelieve what their parents tell them simply because Mommy and Daddy are alwaysright.As children get older,they may discover, unhappily,that Mom and Dad arenotalways correct when it comes to astrophysics, macroeconomics, computer technology,and other specialized fields of knowledge.Although this may cause children to doubtsome of their parents' earlier proclamations, it may not result in utter rejection of thismethod of fixing belief. Instead, some other authority may be sought.Religious beliefs are formed by the method of authority. Long after Catholic childrenhave rejected their parents as the source of all knowledge, particularly about religiousdoctrine, they may still believe that the pope is infallible. Believing the news you seeon television means that you accept CNN or some other news network as an authority.You may believe your professors because they are authorities. Since people lack theresources to investigate everything they learn, much knowledge and many beliefs arefixed by the method of authority.Provided nothing happens to raise doubts about the
6 PART 1 FUNDAMENTALS OF RESEARCH are willing to go to much greater lengths to satisfy their curiosity than are nonscientists. This unwillingness to tolerate unanswered questions and unsolved problems has led science to develop several techniques for obtaining relief from curiosity. It is the careful application of these techniques that distinguishes scientifi c curiosity from everyday curiosity. The common denominator for many of these scientifi c techniques is skepticism. Skepticism is the philosophical belief that the truth of all knowledge is questionable. Therefore, all inquiry must be accompanied by reasonable doubt. No scientifi c fact can be known with 100 percent certainty. For example, bridge engineering is a practical discipline derived from a scientifi c foundation in such fi elds as physics and metallurgy. Most people, when they drive a car across a bridge, do not actively consider that the bridge might collapse. It is a known fact that well-maintained bridges are safe. Yet in the summer of 2007, a bridge in Minneapolis–St. Paul, Minnesota, collapsed. This event will lead to further research, to result in safer bridges being built. Many of the tools, such as statistics, discussed in this text allow the skeptical scientist to measure reasonable doubt. Of what use is scientifi c curiosity? What purpose does it serve? We have stated that psychologists try to determine why people think and act as they do. Let us explore what this means in more detail. ▼ SOURCES OF KNOWLEDGE Fixation of Belief The scientifi c method is a valid way to acquire knowledge about the world around us. What characteristics of the scientifi c approach make it a desirable way to learn about and arrive at beliefs about the nature of things? Perhaps the best way to answer this question is to contrast science with other modes of fi xing belief, since science is only one way in which beliefs are formed. More than one hundred years ago, the American philosopher Charles Sanders Peirce (1877) compared the scientifi c way of knowing with three other methods of developing beliefs. He called these the authority, tenacity, and a priori methods. According to Peirce, the simplest way of fi xing belief is to take someone else’s word on faith. A trusted authority tells you what is true and what is false. Young children believe what their parents tell them simply because Mommy and Daddy are always right. As children get older, they may discover, unhappily, that Mom and Dad are not always correct when it comes to astrophysics, macroeconomics, computer technology, and other specialized fi elds of knowledge. Although this may cause children to doubt some of their parents’ earlier proclamations, it may not result in utter rejection of this method of fi xing belief. Instead, some other authority may be sought. Religious beliefs are formed by the method of authority. Long after Catholic children have rejected their parents as the source of all knowledge, particularly about religious doctrine, they may still believe that the pope is infallible. Believing the news you see on television means that you accept CNN or some other news network as an authority. You may believe your professors because they are authorities. Since people lack the resources to investigate everything they learn, much knowledge and many beliefs are fi xed by the method of authority. Provided nothing happens to raise doubts about the 59533_02_ch01_p001-023.indd 6 9533_02_ch01_p001-023.indd 6 3/4/08 11:47:14 PM /4/08 11:47:14 PM
CHAPTERIEXPLANATIONINSCIENTIFICPSYCHOLOGYcompetence of the authority setting the beliefs, this method offers the great advantagesof minimum effortand substantial security.It is mostpleasant in a troubledworld tohave complete faith in beliefs handed down to you.Anothermethodoffixingbelief is one in whichaperson steadfastlyrefusesto alteracquired knowledge, regardless of evidence to the contrary.The method of tenacity,as it was termed by Peirce, is commonly seen in racial bigots who rigidly cling to astereotype even in the presence of a good counterexample: Although this method ofmaintaining a belief may not be entirely rational, we cannot say it is completely with-out value.The method of tenacity allows peopleto maintain a uniform and constantoutlook on things,so itmayrelieve them froma certain amountof stress and psycho-logicaldiscomfort.The third nonscientific method discussed by Peirce fixes belief a priori. In thiscontext, the term a priori refers to something that is believed without prior study orexamination.Propositionsthatseemreasonablearebelieved.Thisisan extensionofthe method of authority. However, there is no one particular authority being followedblindly in this method.The general cultural outlook is what seems to fix belief apriori.People once believed the world was flat, and it did seem reasonable to suppose thatthe sun revolved around the earth as does the moon.Indeed, the world does look flatifyouarenotina spacecraft.The tenacity and a priori methods are similar in that they minimize the possibilityof being influenced by conflicting opinion.In the method of tenacity,other points ofview, although noticed, are completely discounted. Thus, a racial stereotype is pre-served despite other evidence, such as the good qualities of a person of a different racewho lives next door. In the a priori method, other points of view go unnoticed.Forexample,the sight of a shipdisappearingfrom bottom totop,instead ofall at once,asit leaves port may seem irrelevant if you already know the world is flat.The last of Peirce's methods, the scientific method, fixes belief on the basis ofexperience. Science is based on the assumption that events have causes and that wecan discoverthosecauses through controlled observation.This belief,thatobservablecauses determine events, is known as determinism. If we define scientific psychology(as well as science in general) as a repeatable, self-correcting undertaking that seeks tounderstand phenomena on the basis of empirical observation, then we can see severaladvantagestothe scientific method overthe methods just outlined.Let us seewhat wemean by empirical and self-correcting and examine the advantages associated withthoseaspects of science.The first advantage of the scientific method is its emphasis on empirical observation.None of those other methods relies on data (observations of the world) obtained by sys-tematic observation. In other words, there is no empirical basis for fixing belief. The wordempirical is derived from an old Greek word meaning“experience."Having an empiricalbasis for beliefs means that experience rather than faith is the source of knowledge.Hav-ing one's beliefs fixed by authority carries no guarantee that the authority obtained databefore forming an opinion. By definition, the method of tenacity refuses to consider data.as does the a priori method.Facts that are considered in these othermodes of fixingbe-lief arenot ordinarily obtained by systematicprocedures.For example,casual observationwas the method" that led to the ideas that the world was flat and that frogs spontaneouslygenerated fromthemud each spring,as Aristotlebelieved.The second advantage of science is that it offers procedures for establishing thesuperiority of one belief over another. Persons holding different beliefs will find it difficult
CHAPTER 1 EXPLANATION IN SCIENTIFIC PSYCHOLOGY 7 competence of the authority setting the beliefs, this method offers the great advantages of minimum effort and substantial security. It is most pleasant in a troubled world to have complete faith in beliefs handed down to you. Another method of fi xing belief is one in which a person steadfastly refuses to alter acquired knowledge, regardless of evidence to the contrary. The method of tenacity, as it was termed by Peirce, is commonly seen in racial bigots who rigidly cling to a stereotype even in the presence of a good counterexample. Although this method of maintaining a belief may not be entirely rational, we cannot say it is completely without value. The method of tenacity allows people to maintain a uniform and constant outlook on things, so it may relieve them from a certain amount of stress and psychological discomfort. The third nonscientifi c method discussed by Peirce fi xes belief a priori. In this context, the term a priori refers to something that is believed without prior study or examination. Propositions that seem reasonable are believed. This is an extension of the method of authority. However, there is no one particular authority being followed blindly in this method. The general cultural outlook is what seems to fi x belief a priori. People once believed the world was fl at, and it did seem reasonable to suppose that the sun revolved around the earth as does the moon. Indeed, the world does look fl at if you are not in a spacecraft. The tenacity and a priori methods are similar in that they minimize the possibility of being infl uenced by confl icting opinion. In the method of tenacity, other points of view, although noticed, are completely discounted. Thus, a racial stereotype is preserved despite other evidence, such as the good qualities of a person of a different race who lives next door. In the a priori method, other points of view go unnoticed. For example, the sight of a ship disappearing from bottom to top, instead of all at once, as it leaves port may seem irrelevant if you already know the world is fl at. The last of Peirce’s methods, the scientifi c method, fi xes belief on the basis of experience. Science is based on the assumption that events have causes and that we can discover those causes through controlled observation. This belief, that observable causes determine events, is known as determinism. If we defi ne scientifi c psychology (as well as science in general) as a repeatable, self-correcting undertaking that seeks to understand phenomena on the basis of empirical observation, then we can see several advantages to the scientifi c method over the methods just outlined. Let us see what we mean by empirical and self-correcting and examine the advantages associated with those aspects of science. The fi rst advantage of the scientifi c method is its emphasis on empirical observation. None of those other methods relies on data (observations of the world) obtained by systematic observation. In other words, there is no empirical basis for fi xing belief. The word empirical is derived from an old Greek word meaning “experience.” Having an empirical basis for beliefs means that experience rather than faith is the source of knowledge. Having one’s beliefs fi xed by authority carries no guarantee that the authority obtained data before forming an opinion. By defi nition, the method of tenacity refuses to consider data, as does the a priori method. Facts that are considered in these other modes of fi xing belief are not ordinarily obtained by systematic procedures. For example, casual observation was the “method” that led to the ideas that the world was fl at and that frogs spontaneously generated from the mud each spring, as Aristotle believed. The second advantage of science is that it offers procedures for establishing the superiority of one belief over another. Persons holding different beliefs will fi nd it diffi cult 59533_02_ch01_p001-023.indd 7 9533_02_ch01_p001-023.indd 7 3/4/08 11:47:14 PM /4/08 11:47:14 PM
8PARTIFUNDAMENTALSOFRESEARCHto reconcile their opinions. Science overcomes this problem. In principle, anyone canmake an empirical observation, which means that scientific data can be public and canbe repeatedly obtained. Through public observations, new beliefs are compared with oldbeliefs, and old beliefs are discarded if they do not fit the empirical facts. This does notimply that each and every scientist instantaneously drops outmoded beliefs in favorof new opinions.Changing scientific beliefs is usually a slow process, but eventually incorrect ideas are weeded out.Empirical, public observations are the cornerstone of thescientificmethod,because theymake sciencea self-correcting endeavorTHENATUREOFTHESCIENTIFICEXPLANATIONWhatIsaTheory?A theory can be crudely defined as a set of related statements that explains a varietyofoccurrences.Themoretheoccurrencesandthefewerthestatements,thebetterthetheory.The law of gravity explains falling apples, the behavior of roller coasters, andthe position of bodies within the solar system.With a small number of statements aboutthe mutual attraction of bodies, it explains a large number of events. It is therefore apowerful theory. (This does not necessarily mean it is a correct theory, since there aresomeevents itcannotexplain.)Theory in psychology performs two major functions. First, it provides a frameworkfor the systematic and orderly display of data-that is, it serves as a convenient way forthe scientist to organize data. Even the most dedicated inductive scientist will eventu-ally have difficulty remembering the outcomes of dozens of experiments.Theory canbe used as a kind of filing system to help experimenters organize results.Second, itallows the scientist to generate predictions for situations in which no data have beenobtained.Thegreater the degree ofprecision of these predictions,thebetterthe theoryWith thebest of intentions, scientists who claim to betesting the sametheory oftenderive from the theory different predictions about the same situation.This unfortunatecircumstance is relativelymore common inpsychology,wheremany theoriesarestatedin a loose verbal fashion, than in physics,where theories are more formal and betterquantified through the use of mathematics. Although psychologists are rapidly becom-ing equipped to state their theories moreprecisely through such formal mechanismsasmathematics and computer simulations, the typical psychological theory is still not asprecise as theories in more established, older sciences.Let us see how the theory devised by Latane to account for social loafing stacksup with regard to organization and prediction.The theory of diffusion of responsibil-ity organizes a substantial amount of data about social loafing.More important,thetheory seems to accountfor a remarkable variety of other observations.For example,Latane (1981) notes that the size of a tip left at a restaurant table is inversely relatedto the number of people in the dinner party.Likewise, proportionately more peoplecommitted themselves to Christ at smaller Billy Graham crusades than at larger ones.Finally,workbyLataneand Darley(197o),which isdiscussed indetail laterinthisbook, shows that the willingness of people to help in a crisis is inversely related to thenumberofotherbystanderspresent.Theentirepatternofresults canbesubsumed un-der the notion of diffusion of responsibility, which asserts that people feel less respon-sibilityfor their own actions when theyareina group than whenthey arealone-so
8 PART 1 FUNDAMENTALS OF RESEARCH to reconcile their opinions. Science overcomes this problem. In principle, anyone can make an empirical observation, which means that scientifi c data can be public and can be repeatedly obtained. Through public observations, new beliefs are compared with old beliefs, and old beliefs are discarded if they do not fi t the empirical facts. This does not imply that each and every scientist instantaneously drops outmoded beliefs in favor of new opinions. Changing scientifi c beliefs is usually a slow process, but eventually incorrect ideas are weeded out. Empirical, public observations are the cornerstone of the scientifi c method, because they make science a self-correcting endeavor. ▼ THE NATURE OF THE SCIENTIFIC EXPLANATION What Is a Theory? A theory can be crudely defi ned as a set of related statements that explains a variety of occurrences. The more the occurrences and the fewer the statements, the better the theory. The law of gravity explains falling apples, the behavior of roller coasters, and the position of bodies within the solar system. With a small number of statements about the mutual attraction of bodies, it explains a large number of events. It is therefore a powerful theory. (This does not necessarily mean it is a correct theory, since there are some events it cannot explain.) Theory in psychology performs two major functions. First, it provides a framework for the systematic and orderly display of data—that is, it serves as a convenient way for the scientist to organize data. Even the most dedicated inductive scientist will eventually have diffi culty remembering the outcomes of dozens of experiments. Theory can be used as a kind of fi ling system to help experimenters organize results. Second, it allows the scientist to generate predictions for situations in which no data have been obtained. The greater the degree of precision of these predictions, the better the theory. With the best of intentions, scientists who claim to be testing the same theory often derive from the theory different predictions about the same situation. This unfortunate circumstance is relatively more common in psychology, where many theories are stated in a loose verbal fashion, than in physics, where theories are more formal and better quantifi ed through the use of mathematics. Although psychologists are rapidly becoming equipped to state their theories more precisely through such formal mechanisms as mathematics and computer simulations, the typical psychological theory is still not as precise as theories in more established, older sciences. Let us see how the theory devised by Latané to account for social loafi ng stacks up with regard to organization and prediction. The theory of diffusion of responsibility organizes a substantial amount of data about social loafi ng. More important, the theory seems to account for a remarkable variety of other observations. For example, Latané (1981) notes that the size of a tip left at a restaurant table is inversely related to the number of people in the dinner party. Likewise, proportionately more people committed themselves to Christ at smaller Billy Graham crusades than at larger ones. Finally, work by Latané and Darley (1970), which is discussed in detail later in this book, shows that the willingness of people to help in a crisis is inversely related to the number of other bystanders present. The entire pattern of results can be subsumed under the notion of diffusion of responsibility, which asserts that people feel less responsibility for their own actions when they are in a group than when they are alone—so 59533_02_ch01_p001-023.indd 8 9533_02_ch01_p001-023.indd 8 3/4/08 11:47:14 PM /4/08 11:47:14 PM
CHAPTER1EXPLANATIONINSCIENTIFICPSYCHOLOGYthey are less likely to help in an emergency, they are less likely to leave a large tip,and so on. Latane's theory also makes rather precise predictions about the impact ofthepresence of otherpeople on a person's actions. In fact, one version of the theory(Latane,1981)presents itsmajorassumptionsinterms ofmathematicalequations.Theories are devised to organize concepts and facts into a coherent pattern and topredictadditional observations.Sometimesthetwofunctionsoftheory--organizationandprediction-are called description and explanation, respectively. Unfortunately, for-mulating the roles of theory in this manner often leads to an argument about the relativesuperiority of deductive or inductive approaches to science-a discussion the followingsection concludes is fruitless. According to the deductive scientist, the inductive scientistis concerned only with description. The inductive scientist defends against this charge byretorting that description is explanationif a psychologist could correctlypredict and con-trol all behavior by referring to properly organized sets of results, then that psychologistwould also be explaining behavior.The argument is futile because both views are correct.If all the necessary data were properly organized, predictions could be made withoutrecourseto a formal body oftheoretical statements.Since all the data are not properly or-ganized as yet, and perhaps never will be, theories are required to bridge the gap betweenknowledgeand ignorance.Remember,however,that theorieswill neverbe completebecause all the data will never be available. So, we have merely recast the argument be-tween inductive and deductive views about which approach will more quickly and surelylead to truth. Ultimately,description and explanation may be equivalent. The two termsdescribe the path taken more than they describe the eventual theoretical outcome. Toavoid this pitfall, we shall referto the two major functions of theory as organization andprediction ratherthan as description andexplanation.InductionandDeductionCertain basic elements are shared by all approaches to science. The most important ofthese aredata (empirical observations)and theory (organization of concepts that permitprediction of data). Science needs and uses both data and theory, and our outline of re-search on social loafing indicates that they can be interlinked in a complex way. However,in thehistory of science,individual scientists havediffered about which ismore importantand which comes first. Trying to decide this is a little like trying to decide whether thechicken or the egg comes first. Science attempts to understand why things work the waythey do, and, as we will argue, understanding involves both data and theory.Although Bacon recognized the importance of both data and theory,he believed inthe primacy of empirical observations; modern scientists also emphasize data and viewprogress in science as working from data to theory.Such an approach is an exampleof induction, in which reasoning proceeds from particular data to a general theory.The converse approach, which emphasizes theory predicting data, is called deduction;here, reasoning proceeds from a general theory to particular data (Figure 1.1). Becausemanyscientistsandphilosophersofsciencehavearguedfortheprimacyofoneformofreasoningovertheother,wewill examineinductionand deduction insomedetailBecause empirical observations distinguish science from other modes of fixing belief,many have argued that induction must be the way that science should work.As Harre(1983) states it, “observations and the results of experiments are said to be 'data,'whichprovide a sound and solid basefor the erection of the fragile edifice of scientific thought
CHAPTER 1 EXPLANATION IN SCIENTIFIC PSYCHOLOGY 9 they are less likely to help in an emergency, they are less likely to leave a large tip, and so on. Latané’s theory also makes rather precise predictions about the impact of the presence of other people on a person’s actions. In fact, one version of the theory (Latané, 1981) presents its major assumptions in terms of mathematical equations. Theories are devised to organize concepts and facts into a coherent pattern and to predict additional observations. Sometimes the two functions of theory—organization and prediction—are called description and explanation, respectively. Unfortunately, formulating the roles of theory in this manner often leads to an argument about the relative superiority of deductive or inductive approaches to science—a discussion the following section concludes is fruitless. According to the deductive scientist, the inductive scientist is concerned only with description. The inductive scientist defends against this charge by retorting that description is explanation—if a psychologist could correctly predict and control all behavior by referring to properly organized sets of results, then that psychologist would also be explaining behavior. The argument is futile because both views are correct. If all the necessary data were properly organized, predictions could be made without recourse to a formal body of theoretical statements. Since all the data are not properly organized as yet, and perhaps never will be, theories are required to bridge the gap between knowledge and ignorance. Remember, however, that theories will never be complete, because all the data will never be available. So, we have merely recast the argument between inductive and deductive views about which approach will more quickly and surely lead to truth. Ultimately, description and explanation may be equivalent. The two terms describe the path taken more than they describe the eventual theoretical outcome. To avoid this pitfall, we shall refer to the two major functions of theory as organization and prediction rather than as description and explanation. Induction and Deduction Certain basic elements are shared by all approaches to science. The most important of these are data (empirical observations) and theory (organization of concepts that permit prediction of data). Science needs and uses both data and theory, and our outline of research on social loafi ng indicates that they can be interlinked in a complex way. However, in the history of science, individual scientists have differed about which is more important and which comes fi rst. Trying to decide this is a little like trying to decide whether the chicken or the egg comes fi rst. Science attempts to understand why things work the way they do, and, as we will argue, understanding involves both data and theory. Although Bacon recognized the importance of both data and theory, he believed in the primacy of empirical observations; modern scientists also emphasize data and view progress in science as working from data to theory. Such an approach is an example of induction, in which reasoning proceeds from particular data to a general theory. The converse approach, which emphasizes theory predicting data, is called deduction; here, reasoning proceeds from a general theory to particular data (Figure 1.1). Because many scientists and philosophers of science have argued for the primacy of one form of reasoning over the other, we will examine induction and deduction in some detail. Because empirical observations distinguish science from other modes of fi xing belief, many have argued that induction must be the way that science should work. As Harré (1983) states it, “observations and the results of experiments are said to be ‘data,’ which provide a sound and solid base for the erection of the fragile edifi ce of scientifi c thought” 59533_02_ch01_p001-023.indd 9 9533_02_ch01_p001-023.indd 9 3/4/08 11:47:14 PM /4/08 11:47:14 PM