Experiments, Human

In the social sciences, human experimentation involves the study of human behavior under controlled conditions using scientific methods. The practice of using human beings as experimental subjects was borrowed from the medical sciences in the late nineteenth century by those who later were credited with helping to lay the foundation for modern psychology. Separately, William James (1842–1910) in the United States and Wilhelm Wundt (1832–1920) in Germany established the first experimental psychology laboratories in 1875. These pioneers conducted simple experiments involving human perception, memory, and cognition. Their success with the experimental approach revolutionized the study of human behavior and significantly influenced the development of all of the social sciences throughout the twentieth century. Today human experiments are widely accepted as an important research tool not only in psychology, but also in sociology, economics, and other specialized fields.

Experiments using human subjects can assume a wide variety of designs and employ simple to complex procedures. The most basic form of a human experiment involves two sets of subjects—a treatment group and a control group. Subjects in the treatment group are exposed to some form of stimulus (experience) that is under controlled manipulation by the experimenter. Subjects in the control group do not receive the stimulus, but are like the treatment group in all other respects. The resulting effect of the stimulus on the treatment group is then measured and compared to the control group. For example, a researcher interested in the effect of background noise on students’ reading comprehension may design an experiment where students in a treatment group are asked to read a passage from a book while a radio is played nearby; meanwhile, students in a control group are asked to read the same passage, but in a noiseless environment. Both the treatment group and control group students then take a test on the assigned reading and the test results are quantitatively compared and contrasted. Researchers can manipulate various elements of an experiment to test a variety of hypotheses. In this example, the researcher could examine how the type of noise independently affects reading comprehension by alternating music with talk, or even white noise, while holding all of the other elements the same. Likewise, the effects of age or gender could be explored by selecting human subjects from differing populations. Thus, even a simply designed experiment can be a powerful research tool. Beginning with this basic approach, social scientists over the past century developed sophisticated techniques and procedures to study a vast array of human behavior. However, the widespread practice of human experimentation also caused social scientists to carefully examine their own motives and ethics.

ETHICAL CONSIDERATIONS

Just as the modern history of using human beings as experimental subjects in biomedical research is littered with controversy and scandal, the same is true in the social sciences. In the decades following World War II a number of human experiments made headline news due to the ethical questions that they raised. The most noteworthy of these include Stanley Milgram’s “obedience to authority” study in 1963 and the Philip Zimbardo’s “imprisonment” study in 1973.

In Milgram’s study an experimenter instructed human subjects to administer increasingly severe electrical shocks to another, unseen person. Unknown to the subjects, the shocks were fictitious and the other person was collaborating with the experimenter. In response to the “shocks” the collaborator would scream, leading the subject to believe that the shocks were real. Milgram conducted the study to explore how people respond to authority figures when directed to perform harmful acts against other human beings. Likewise, Zimbardo too was interested in studying the human reaction to authority, but did so in a simulated prison context. Zimbardo assigned “guard” and “prisoner” roles to subjects and then proceeded to observe their behavior as subjects were instructed to undertake various activities common to life inside a U.S. prison. The experiment took place in a college laboratory especially redesigned, complete with cells, to simulate a prison environment. During the course of the experiment the confrontations between the guards and the prisoners became so intense that a prisoner rebellion ensued and a breakout was attempted. Given these events, concern for the physical and mental safety of the subjects caused the experiment to be terminated prior to its planned conclusion.

Although no one was seriously harmed in either study, the Milgram and Zimbardo experiments are often cited along with notorious cases in biomedical research, such as the decades–long “Tuskeegee syphilis study” in which, to serve as a control group, poor African Americans infected with syphilis were denied medical treatment; the fallout from this experiment led to regulatory oversight of human subjects research in the United States and in other nations. In 1974 the U.S. Congress passed the National Research Act, which established a National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research. This body’s 1979 “Belmont Report” (named after the conference center where the commission met) set forth the three basic ethical and moral principles that serve as the foundation for the regulatory rules that now govern all human experiments conducted at institutions receiving funds from the U.S. federal government. These three principles are respect, beneficence, and justice.

The principle of respect includes the tenet that experimental researchers should honor all human subjects’ right to personal dignity, freedom of choice, and privacy. The beneficence principle stipulates that researchers conducting human experiments have a societal obligation to maximize the benefits and minimize the costs associated with their work. Finally, the principle of justice concerns the obligation of researchers to treat all human subjects with fairness.

The Belmont Report proposed that each of the three basic principles have equal moral weight and recognized that in some situations they may conflict with each other. Therefore, the commission recommended that experiments using human subjects should be objectively evaluated and judged based on their own merits relative to all three principles. This perspective is clearly reflected in the prevailing federal regulations that shape the way human experiments are conducted today.

REGULATORY ISSUES

The primary regulations that govern the practice of human experiments in the United States are included in the Federal Policy for the Protection of Human Subjects (Code of Federal Regulations Title 45–Part 46). This policy is often referred to as the “Common Rule” because it has been adopted by sixteen federal departments and agencies that conduct or financially support research using human subjects. The Common Rule is explicitly based on the Belmont Report’s three ethical and moral principles.

Under the principle of respect, the Common Rule regulations require researchers to explicitly obtain each human subject’s informed consent before proceeding with any experiment. All potential benefits and harms to the human subject must be clearly explained and each subject must have the option of quitting the experiment at any time. The regulations also require researchers to maintain the privacy of their human subjects by not divulging the names or any personally identifying information collected during the course of an experiment.

To uphold the principle of beneficence, the Common Rule regulations require researchers to ensure that all human experiments possess a favorable ratio of potential benefits to potential risks. Furthermore, researchers must demonstrate that they are capable of properly conducting human experiments and that they have procedures in place to handle the apparent risks.

Federal regulations derived from the principle of justice include the requirement that human subjects be selected in a manner such that the risks and benefits of participation are equitably shared across participants. The justice principle is also the foundation for a variety of rules that ensure that vulnerable populations are not exploited by researchers conducting human experiments. Thus, numerous regulations safeguard prisoners, children, the mentally impaired, and other special groups.

Enforcement of the Common Rule regulations is a decentralized process, and primary oversight is at the local level. The policy mandates the establishment of institutional review boards (IRBs, also known as internal review boards) at all institutions, including universities and research centers, that conduct human experiments and receive federal dollars. An IRB is composed of professional researchers and administrators who screen proposals for research involving human subjects. Researchers wishing to conduct human experiments, or any other research activity that includes the observation of human behavior or the collection of data from human beings, must receive approval from their institution’s IRB before proceeding. Local IRBs are charged with enforcing the federal policies and protecting the rights of human subjects. Institutions have a powerful incentive to maintain a diligent IRB because the code allows for the withdrawal of all federal funding from institutions found in violation of the Common Rule.

The influence of the Common Rule and the institutionalization of local IRBs is a topic of debate among many American social scientists. Most agree that enforcement of the Common Rule does protect human subjects from overtly risky experimental practices, but some argue that the federal code stifles research activities that inherently carry low levels of risk. For example, researchers proposing to conduct a marketing survey or an oral history project must receive either approval or an exemption from their local IRB, even though the personal risk of participating in either of these practices is negligible. An IRB review requires paperwork and time commitments that may discourage some researchers from pursuing a project. Additionally, the decentralized approach of enforcing the Common Rule results in an uneven application of the regulations. Projects that receive approval from one local IRB may not be approved by another IRB, causing difficulties for research teams composed of members from different institutions. Even though these hurdles exist, the number of empirical research studies using human subjects, as recorded in the academic literature, continues to increase each year with little evidence to suggest that the regulations have significantly affected the quantity of research conducted.

BIBLIOGRAPHY

Friedman, Daniel, and Shyam Sunder. 1994. Experimental Methods: A Primer for Economists. New York: Cambridge University Press.

Levine, Robert J. 1988. Ethics and Regulation of Clinical Research. 2nd ed. New Haven, CT: Yale University Press.

Snodgrass, Joan G., Gail L. Berger, and Martin Haydon. 1985. Human Experimental Psychology. New York: Oxford University Press.

United States Department of Health, Education, and Welfare. 2005. Code of Federal Regulations. Title 45, Public Welfare. Part 46, Protection of Human Subjects. http://www.hhs.gov/ohrp/humansubjects/guidance/45cfr46.htm.

Zimbardo, Phillip G. 2006. Homepage of Professor Phillip G. Zimbardo. http://www.zimbardo.com/.

Paul W. Grimes