{"id":67,"date":"2019-09-17T12:19:26","date_gmt":"2019-09-17T16:19:26","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/part\/experimental-research\/"},"modified":"2019-09-17T12:19:26","modified_gmt":"2019-09-17T16:19:26","slug":"experimental-research","status":"publish","type":"part","link":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/part\/experimental-research\/","title":{"raw":"Chapter 6: Experimental Research","rendered":"Chapter 6: Experimental Research"},"content":{"raw":"\n
\n\nIn the late 1960s social psychologists John Darley and Bibb Latan\u00e9 proposed a counterintuitive hypothesis. The more witnesses there are to an accident or a crime, the less likely any of them is to help the victim (Darley & Latan\u00e9, 1968)[footnote]Darley, J. M., & Latan\u00e9, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology, 4<\/em>, 377\u2013383.[\/footnote].<\/span>\n

 They also suggested the theory that this phenomenon occurs because each witness feels less responsible for helping\u2014a process referred to as the \u201cdiffusion of responsibility.\u201d Darley and Latan\u00e9 noted that their ideas were consistent with many real-world cases. For example, a New York woman named Catherine \u201cKitty\u201d Genovese was assaulted and murdered while several witnesses evidently failed to help. But Darley and Latan\u00e9 also understood that such isolated cases did not provide convincing evidence for their hypothesized \u201cbystander effect.\u201d There was no way to know, for example, whether any of the witnesses to Kitty Genovese\u2019s murder would have helped had there been fewer of them.<\/span><\/p>\n

So to test their hypothesis, Darley and Latan\u00e9 created a simulated emergency situation in a laboratory. Each of their university student participants was isolated in a small room and told that he or she would be having a discussion about university life with other students via an intercom system. Early in the discussion, however, one of the students began having what seemed to be an epileptic seizure. Over the intercom came the following: \u201cI could really-er-use some help so if somebody would-er-give me a little h-help-uh-er-er-er-er-er c-could somebody-er-er-help-er-uh-uh-uh (choking sounds)\u2026I\u2019m gonna die-er-er-I\u2019m\u2026gonna die-er-help-er-er-seizure-er- [chokes, then quiet]\u201d (Darley & Latan\u00e9, 1968, p. 379)<\/span>[footnote]Darley, J. M., & Latan\u00e9, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology, 4<\/em>, 377\u2013383.[\/footnote].<\/p>\nIn actuality, there were no other students. These comments had been prerecorded and were played back to create the appearance of a real emergency. The key to the study was that some participants were told that the discussion involved only one other student (the victim), others were told that it involved two other students, and still others were told that it included five other students. Because this was the only difference between these three groups of participants, any difference in their tendency to help the victim would have to have been caused by it. And sure enough, the likelihood that the participant left the room to seek help for the \u201cvictim\u201d decreased from 85% to 62% to 31% as the number of \u201cwitnesses\u201d increased.\n

\n

The Parable of the 38 Witnesses<\/b><\/p>\nThe story of Kitty Genovese has been told and retold in numerous psychology textbooks. The standard version is that there were 38 witnesses to the crime, that all of them watched (or listened) for an extended period of time, and that none of them did anything to help. However, recent scholarship suggests that the standard story is inaccurate in many ways (Manning, Levine, & Collins, 2007)<\/span>[footnote]Manning, R., Levine, M., & Collins, A. (2007). The Kitty Genovese murder and the social psychology of helping: The parable of the 38 witnesses. American Psychologist, 62<\/em>, 555\u2013562.[\/footnote]. For example, only six eyewitnesses testified at the trial, none of them was aware that he or she was witnessing a lethal assault, and there have been several reports of witnesses calling the police or even coming to the aid of Kitty Genovese. Although the standard story inspired a long line of research on the bystander effect and the diffusion of responsibility, it may also have directed researchers\u2019 and students\u2019 attention away from other equally interesting and important issues in the psychology of helping\u2014including the conditions in which people do in fact respond collectively to emergency situations.<\/span>\n\n<\/div>\nThe research that Darley and Latan\u00e9 conducted was a particular kind of study called an experiment. Experiments are used to determine not only whether there is a meaningful relationship between two variables but also whether the relationship is a causal one that is supported by statistical analysis. For this reason, experiments are one of the most common and useful tools in the psychological researcher\u2019s toolbox. In this chapter, we look at experiments in detail. We will first consider what sets experiments apart from other kinds of studies and why they support causal conclusions while other kinds of studies do not. We then look at two basic ways of designing an experiment\u2014between-subjects designs and within-subjects designs\u2014and discuss their pros and cons. Finally, we consider several important practical issues that arise when conducting experiments.<\/span>\n\n<\/div>\n","rendered":"

\n

In the late 1960s social psychologists John Darley and Bibb Latan\u00e9 proposed a counterintuitive hypothesis. The more witnesses there are to an accident or a crime, the less likely any of them is to help the victim (Darley & Latan\u00e9, 1968)[1]<\/sup><\/a>.<\/span><\/p>\n

 They also suggested the theory that this phenomenon occurs because each witness feels less responsible for helping\u2014a process referred to as the \u201cdiffusion of responsibility.\u201d Darley and Latan\u00e9 noted that their ideas were consistent with many real-world cases. For example, a New York woman named Catherine \u201cKitty\u201d Genovese was assaulted and murdered while several witnesses evidently failed to help. But Darley and Latan\u00e9 also understood that such isolated cases did not provide convincing evidence for their hypothesized \u201cbystander effect.\u201d There was no way to know, for example, whether any of the witnesses to Kitty Genovese\u2019s murder would have helped had there been fewer of them.<\/span><\/p>\n

So to test their hypothesis, Darley and Latan\u00e9 created a simulated emergency situation in a laboratory. Each of their university student participants was isolated in a small room and told that he or she would be having a discussion about university life with other students via an intercom system. Early in the discussion, however, one of the students began having what seemed to be an epileptic seizure. Over the intercom came the following: \u201cI could really-er-use some help so if somebody would-er-give me a little h-help-uh-er-er-er-er-er c-could somebody-er-er-help-er-uh-uh-uh (choking sounds)\u2026I\u2019m gonna die-er-er-I\u2019m\u2026gonna die-er-help-er-er-seizure-er- [chokes, then quiet]\u201d (Darley & Latan\u00e9, 1968, p. 379)<\/span>[2]<\/sup><\/a>.<\/p>\n

In actuality, there were no other students. These comments had been prerecorded and were played back to create the appearance of a real emergency. The key to the study was that some participants were told that the discussion involved only one other student (the victim), others were told that it involved two other students, and still others were told that it included five other students. Because this was the only difference between these three groups of participants, any difference in their tendency to help the victim would have to have been caused by it. And sure enough, the likelihood that the participant left the room to seek help for the \u201cvictim\u201d decreased from 85% to 62% to 31% as the number of \u201cwitnesses\u201d increased.<\/p>\n

\n

The Parable of the 38 Witnesses<\/b><\/p>\n

The story of Kitty Genovese has been told and retold in numerous psychology textbooks. The standard version is that there were 38 witnesses to the crime, that all of them watched (or listened) for an extended period of time, and that none of them did anything to help. However, recent scholarship suggests that the standard story is inaccurate in many ways (Manning, Levine, & Collins, 2007)<\/span>[3]<\/sup><\/a>. For example, only six eyewitnesses testified at the trial, none of them was aware that he or she was witnessing a lethal assault, and there have been several reports of witnesses calling the police or even coming to the aid of Kitty Genovese. Although the standard story inspired a long line of research on the bystander effect and the diffusion of responsibility, it may also have directed researchers\u2019 and students\u2019 attention away from other equally interesting and important issues in the psychology of helping\u2014including the conditions in which people do in fact respond collectively to emergency situations.<\/span><\/p>\n<\/div>\n

The research that Darley and Latan\u00e9 conducted was a particular kind of study called an experiment. Experiments are used to determine not only whether there is a meaningful relationship between two variables but also whether the relationship is a causal one that is supported by statistical analysis. For this reason, experiments are one of the most common and useful tools in the psychological researcher\u2019s toolbox. In this chapter, we look at experiments in detail. We will first consider what sets experiments apart from other kinds of studies and why they support causal conclusions while other kinds of studies do not. We then look at two basic ways of designing an experiment\u2014between-subjects designs and within-subjects designs\u2014and discuss their pros and cons. Finally, we consider several important practical issues that arise when conducting experiments.<\/span><\/p>\n<\/div>\n

  1. Darley, J. M., & Latan\u00e9, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology, 4<\/em>, 377\u2013383. ↵<\/a><\/li>
  2. Darley, J. M., & Latan\u00e9, B. (1968). Bystander intervention in emergencies: Diffusion of responsibility. Journal of Personality and Social Psychology, 4<\/em>, 377\u2013383. ↵<\/a><\/li>
  3. Manning, R., Levine, M., & Collins, A. (2007). The Kitty Genovese murder and the social psychology of helping: The parable of the 38 witnesses. American Psychologist, 62<\/em>, 555\u2013562. ↵<\/a><\/li><\/ol><\/div>","protected":false},"parent":0,"menu_order":6,"template":"","meta":{"pb_part_invisible":false,"pb_part_invisible_string":""},"contributor":[],"license":[],"class_list":["post-67","part","type-part","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/pressbooks\/v2\/parts\/67","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/pressbooks\/v2\/parts"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/wp\/v2\/types\/part"}],"version-history":[{"count":0,"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/pressbooks\/v2\/parts\/67\/revisions"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/wp\/v2\/media?parent=67"}],"wp:term":[{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/wp\/v2\/contributor?post=67"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/rmethodspsych\/wp-json\/wp\/v2\/license?post=67"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}