What follows is a brief primer about some significant historical events and foundational documents that have been critical to the development of contemporary research ethics standards. This primer is not meant to tell the full story of all events nor can it ever replace what can be learned by reviewing the primary sources directly. Rather, this primer is meant to reduce response effort by conveniently bringing together and summarizing information that has been published in disparate locales, to provide the reader with a robust reference list that can be used as a starting point to dig deeper into each of the events and documents described, and to provide the base upon which links to the field of behavior analysis can be made in the subsequent section.

Early Behavioral and Medical Research with Human Participants (1920–1939)

Although questions about how the human body functions and why people behave the way they do probably have been around as long as humans have existed, this primer begins in the early 1920s to emphasize research activities that have occurred under reasonably similar circumstances to today’s research activities (e.g., often in a university or clinical setting, to answer specific research questions, with the purpose of disseminating the findings to change practice or policy). The three research projects briefly summarized here were selected to represent the types of research activities that occurred with some degree of regularity before modern policies were established. Of course, the summaries do not do justice to the complete and complex stories of those who suffered as a result of these research projects. Readers are encouraged to consult cited sources for further details.

Little Albert Research (1920)

The story of Little Albert is frequently told in introductory psychology textbooks—both as a cautionary tale and to share the empirical findings (Harris, 1979). In 1920, John Watson and Rosalie Rayner described a research project in which they conditioned a fear response to be demonstrated by an infant, Albert, in response to a previously neutral stimulus (a white rat) by pairing the stimulus with the loud sound of a hammer hitting a steel bar. Through various follow-up analyses to test generalization and further conditioning, Albert’s fear response was subsequently conditioned to other stimuli and explicit steps were never taken to reverse the conditioning (Harris, 1979). Many uncertainties and mysteries surround the Little Albert research activities (for further discussion on the topic, see Digdon, 2020; Digdon et al., 2014; Frilund et al., 2020; Harris, 2020). Some of these claims include suggestions that Albert might have been born with a neurological impairment (Frilund et al., 2020) and that Watson and Rayner knew that Albert was going to be discharged from the hospital before the conditioning could be reversed (Harris, 1979). Establishing the veracity of these claims is far beyond the scope of the article, but, nonetheless, the Little Albert story is a cautionary tale about the responsibility a researcher must take if working with a vulnerable participant and studying a behavioral phenomenon that both could be harmful to the individual and serves no direct benefit for that person.

Tuskegee Syphilis Study (1932–1973)

In 1932, a group of medical researchers began studying syphilis at the Tuskegee Institute in Alabama, USA (Tobin, 2022). Hundreds of Black men with syphilis, many of whom were economically and socially vulnerable and unaware of their diagnosis, were enrolled in the study under the illusion that they would be receiving free medical care. Instead, the researchers were interested in learning about untreated syphilis and willfully withheld known treatment regimens. Even after many of the participants died, the study continued until information about the project made its way into the mainstream news in a Washington Star article in 1972 (Tobin, 2022). The 40-year study was subsequently halted and discussed at legislative hearings that set the stage for the development of the National Research Act of 1974 (discussed later in the current primer).

The abhorrent treatment of the men in this study is a sobering reminder that deception in research can lead to life-and-death stakes, especially when working with vulnerable populations. Furthermore, this is an example of one group bearing an undue burden in research. The participants in this project were subjected to extreme risk whereas the benefits of the research were exclusively provided to an entirely different group. It is worth noting that this was not a secret project run outside the bounds of peer review; rather, updates about the study’s findings were published in the Journal of the American Medical Association in 1936 and every half-decade or so until 1973 (Tobin, 2022); as such, this atrocity cannot be blamed solely on a rogue group of scientists. The variables responsible for the unethical treatment of the research participants in this case needed to be addressed in a systematic manner that considered the full context in which the research occurred.

Tudor Stuttering Study (The “Monster Study”) (1939)

In the early 1900s, Wendell Johnson, a faculty member at the University of Iowa in the USA, ran an established research lab that evaluated variables related to stuttering (Ambrose & Yairi, 2002). In 1939, a graduate student of his, Mary Tudor, conducted a study at a nearby orphanage to answer questions about whether stuttering could be induced by telling children that they had speech disfluencies. The results suggested that, at least in some cases, individuals with typical speech patterns could develop stuttering behaviors after being told that they demonstrated pathological speech tendencies. Similar to the Little Albert study, this study raises questions about the ethics of establishing problematic behaviors where previously none existed and not planning to reverse any potential harmful effects. This is particularly peculiar in this situation because Johnson, the thesis advisor, had a known history of stuttering himself and was well-acquainted with the social and communication issues associated with stuttering (Reynolds, 2006).

The advisor–graduate student dynamic presents another issue. Did Tudor have the proper competency and oversight to carry out such a study (Ambrose & Yairi, 2002)? Or, if Tudor had apprehensions about the procedures, would she have had the ability to halt or alter the study within the power differential of the advisor–advisee relationship? There is written evidence to suggest that Tudor voiced some concerns to Johnson during and after the study and that Johnson seems to have buried the results after the study was completed (Ambrose & Yairi, 2002). This prompts important questions about responsibility, competence, training, and supervision in graduate student research activities.

Criminal Research Activities Related to World War II (mid-1930s–1947)Nazi Experimentation (mid-1930s–1945)

One of the many atrocities of World War II was the medical experimentation conducted on prisoners by physicians at Nazi camps. According to the U.S. Holocaust Memorial Museum (2006), the types of unethical medical experimentation undertaken by Nazis included life-threatening research about topics such as altitude limits of parachuting, treatments for hypothermia, ways to produce potable water, methods for treating lethal injuries and illnesses through inflicting such ailments on otherwise healthy individuals, and techniques for mass sterilization and eugenics. Furthermore, when individuals died in the course of this research or for other reasons at the camps, their bodies often then were violated for experimentation as well (Weindling et al., 2016). Although the full death toll and count of victims of Nazi research may never be known for certain, some researchers have reported that, at a minimum, there were over 15,000 confirmed victims but the actual number likely is more than double that figure (Weindling et al., 2016, p. 1). It is clear that these horrific acts carried out in the name of research highlight several violations of human rights. The prisoners were subjected to deadly conditions with absolutely no benefit to them, and they were included in the experimentation involuntarily.

Nuremberg Medical Trial (the Doctors’ Trial) and the Nuremberg Code (1946–1947)

In late 1946, criminal proceedings were brought against 23 individuals for their alleged roles in the aforementioned Nazi experimentation; these proceedings came to be known as the “Nuremberg Medical Trial” or the “Doctors’ Trial” (U.S. Holocaust Memorial Museum, n.d. a). As the court considered the occurrence of criminal acts, research ethics suddenly held a spotlight on a worldwide stage. Given the lack of standardized research norms or written policies, Leo Alexander, a physician who was working with the prosecution, drafted a memo in April 1947 that included six requirements for “legitimate research” (U.S. Holocaust Memorial Museum, n.d. b). These requirements were reframed and augmented in the August 1947 verdict of the trial (Nuremberg Military Tribunals, 1949, pp.181–184). The updated list of 10 points became known as the “Nuremberg Code,” which described the requirements for “Permissible Medical Experiments” (hereafter referred to as the Nuremberg Code).

It should be noted that the Nuremberg Code was written to address research in general—not solely as a retrospective condemnation of the Nazi experimentation (Weindling, 2022). As such, the Nuremberg Code became a foundational ethics document upon which future documents and policies were designed. The Nuremberg Code can be found in its entirety on the U.S. Holocaust Memorial Museum’s website (U.S. Holocaust Memorial Museum, n.d. b). Due to the far-reaching formative importance of the document, the ten basic principles are included in Table 1 for easy review by readers.

Table 1 The Ten Principles Listed in the Nuremberg Code (adapted from United States Holocaust Memorial Museum, n.d.-b)Mid-Century Behavioral and Medical Research with Human Participants (1950s–1998)

With the development of the Nuremberg Code, expectations for research ethics with human participants were established within the verdict of the trial, but it would take a few more decades until the principles were codified and applied to medical and behavioral research activities broadly. Even though the Nuremberg Code was available to researchers in the mid-20th century, harmful research practices continued. Once again, this section is not meant to provide an exhaustive list nor are the summaries meant to fully describe the circumstances or impact of each situation. Rather, these synopses provide a sample of some research that has occurred more recently and highlight the risks of research occurring without standardized expectations and oversight.

Willowbrook State School Hepatitis Studies (1950s–1970s)

Willowbrook State School was a residential facility in Staten Island, New York, USA, that was established to serve children with disabilities (Goode et al., 2013). Willowbrook is well-known for extreme abuses and deplorable conditions that were made public by Senator Robert Kennedy, journalist Geraldo Rivera, and others in the 1960s and early 1970s. However, germane to this article, Willowbrook also was the site of an expansive research program. Chapter 2 of Goode et al. (2013) provides an overview of the types of medical and behavioral research that were undertaken on the children at Willowbrook, including research about hepatitis and other infectious diseases in response to outbreaks at the facility. Under the direction of Saul Krugman, hundreds of children who did not have hepatitis were infected with the virus when Krugman fed them hepatitis samples collected from the feces of infected children (Goode et al., 2013). Once again, research activities were being conducted with a vulnerable population and exposing them to a high level of risk (almost certain infection with hepatitis) with little to no likelihood of direct benefit to the participants themselves.

Krugman defended his work by stating, among other rationales, that he had obtained consent from the parents of the children. Goode et al. (2013) noted that there is reason to assume that parents were led to believe that consenting to participation in research activities would move their children to the top of Willowbrook’s long waiting list and may not have thoroughly understood the risks involved. Thus, even if parents signed Kruger’s forms, it is likely that the consent process involved coercion with the contingent offer of admission. This also highlights the tenuous boundaries of clinical activities and research activities and potential conflicts of interest when working in a clinical research context.

Henrietta Lacks and Her HeLa Cells (1951–ongoing)

The story of Henrietta Lacks, a Black woman who sought care for cervical cancer at Johns Hopkins University in the USA in the 1950s, is one that still is unresolved and at the center of current medical research ethics controversies (Henrietta Lacks: Science Must Right a Historical Wrong [Editorial], 2020). During the course of the medical care Lacks received, cancerous cells were extracted and studied in a laboratory. Researchers noticed that her cells had the unique ability to “survive and reproduce; they were, in essence, immortal,” (Henrietta Lacks: Science Must Right a Historical Wrong [Editorial], 2020, p. 7). Unbeknownst to Lacks or her family, the cells, named HeLa cells in the research community, were shared widely and have been used in the development of thousands of medical discoveries around the world.

The history of HeLa cells brings up several research ethics questions and concerns. First, the cells were shared without the knowledge or consent of the individual. Second, compensation, acknowledgement, or limits on the bounds of use were never discussed. Third, privacy was not adequately considered or protected. Her cells, which contain extremely personal genetic information, are in the public domain—violating not only her privacy but also the medical privacy of her descendants. As recently as 2013, the full details of a genome sequence of a HeLa strain were posted online and sparked a controversy about the privacy of the living descendants of Lacks (Greely & Cho, 2013). Although HeLa cells continue to be used in medical research, including in the development of Coronavirus Disease (COVID-19) vaccines (Henrietta Lacks: Science Must Right a Historical Wrong [Editorial], 2020), the ethical questions continue to linger.

Milgram Study of Obedience (early 1960s)

A third example of mid-century research, Stanley Milgram’s study of obedience, probably is familiar to anyone who has taken an introductory psychology course due to its infamous standing as an example of unethical research practices (Tolich, 2014). In the early 1960s, Milgram set out to study the effects of authority on obedience. He set up a situation in which research participants assumed the role of a teacher and a confederate (who the participant thought was another research participant) took the role of a learner (Milgram, 1963, 1974). The experimenter briefed the participant about how they would “teach” the other participant to correctly answer questions by delivering electric shocks after incorrect answers. Unbeknownst to the participant, no actual shocks would be delivered to the confederate learner. During the course of the session, the participant was instructed by the experimenter to administer what appeared to them to be more and more dangerous degrees of electric shocks. Even when the learner expressed extreme discomfort and the participant indicated that they wanted to stop administering shocks, the experimenter instructed the participant to continue. Over half of the participants continued to administer shocks to what, from their perspective, appeared to be a dangerous or even deadly level of shock to the learner.

Milgram (1963) discussed at length the various indices of distress demonstrated by the participants including verbal protests, sweating, nervous laughing, seizures, etc. The participants of the study were never offered follow-up support to process the distress that they experienced during the study (Tolich, 2014). The Milgram study is a reminder that the wellbeing of research participants does not only apply to physical safety. Even though the participants in the Milgram study were not being exposed to infectious diseases or taught maladaptive patterns of behavior like some of the other examples explored here, they still likely were experiencing adverse events that were the responsibility of the researchers to mitigate.

Rekers and Lovaas: “Behavioral Treatment of Deviant Sex-Role Behaviors in a Male Child” (1974)

Although the previous three examples have come from the medical field or psychology in general, the following situation has played out in the field of ABA and its flagship journal, JABA. In 1974, Rekers and Lovaas published an article in JABA that described a study in which the behavior of a 4-year-old boy, “Kraig,” was modified by reinforcing “masculine behaviors” and extinguishing and punishing “feminine behaviors.” This work was initiated as part of dissertation research by George Rekers while he was a doctoral student at the University of California, Los Angeles, USA, working under the supervision of O. Ivar Lovaas (Rekers, 1972). Almost immediately, contemporaneous critiques of the article and the ethics of the study were submitted to and published in JABA (Nordyke et al., 1977; Winkler, 1977). Nordyke et al. (1977) questioned the ethics of the selection of the target behaviors labeled as deviant and nondeviant in Rekers and Lovaas (1974) and then proceeded to systematically provide counterarguments to the four rationales described by Rekers and Lovaas. Winkler (1977, p. 549) also raised a concern about the selection of the target behaviors, writing, “The study raises a fundamental question, to whom does the therapist owe first allegiance: to the client (or in this case the client’s parents), to the therapist’s own values, or to prevailing relevant social norms?”

The study and controversy surrounding it resurfaced approximately 3 decades later after Kraig, whose real name was Kirk Andrew Murphy, died by suicide in 2003 (Johnson, 2022). Kirk’s family began speaking out in public, including with journalist Anderson Cooper (Cooper, 2011), and providing firsthand accounts of the devastating impact—both in the short and long term—of Rekers and Lovaas (1974). There was a subsequent resurgence among behavior analysts and the readership of JABA to condemn the actions taken by Rekers and Lovaas in the name of ABA research (Johnson, 2022). One result of this call for action was the publication of an Editor’s Note by the Society for the Experimental Analysis of Behavior (SEAB) and Linda LeBlanc, editor-in-chief of JABA, that made an official “Expression of Concern” about Rekers and Lovaas (1974; SEAB & LeBlanc, 2020). This expression of concern detailed harms that have resulted from Rekers and Lovaas (1974) but stopped short of retracting the article because “the available evidence does not make it clear that the original study was unethical by the standards of that day” (SEAB & LeBlanc, 2020, p. 1832). Subsequent discourse continues in the literature. Johnson (2022) makes the case that evidence does exist to support the retraction of the article. Both Capriotti and Donaldson (2022) and Conine et al. (2022) offer suggestions for what behavior analysts and the field of ABA can do now to address the harm that has been caused by Rekers and Lovaas (1974). As reparations are made, Rekers and Lovaas (1974) remains a grievous reminder that research activities can have long-term negative effects, especially in cases in which target behaviors are not selected in the best interest of the participant, when participants are not given the opportunity to accept or decline the opportunity to participate in research, and when harmful or abusive procedures are used as part of the method.

Wakefield’s Publication Erroneously Linking Vaccines and Autism Spectrum Disorder (1998)

Behavior analysts who work with individuals diagnosed with autism spectrum disorder (ASD) and their families likely, at some point in their career, will be asked about a link between ASD and vaccines. This myth and related misinformation that has been perpetuated for nearly two and a half decades traces back to unethical research conduct by Andrew Wakefield in the late 1990s (Davidson, 2017). Wakefield, a physician in London, United Kingdom (UK), published data suggesting that there was a causal link between the administration of the measles, mumps, and rubella (MMR) vaccine and the onset of behavioral patterns related to ASD (Wakefield et al., 1998). This link made sense to many given that signs of ASD often occur around two years of age—the same timeframe that the MMR vaccine typically is delivered. Despite a distinct lack of corroborating data or scientific replication, the theory gathered momentum among parents’ groups, mainstream media, and politicians alike (Davidson, 2017) and has been linked to vaccine hesitancy and increases in preventable outbreaks of related diseases (DeStefano & Shimabukuro, 2019).

In 2004, the editors of The Lancet, the journal in which Wakefield et al. (1998) had been published, released a statement announcing that “serious allegations of research misconduct” had been made in regards to Wakefield et al. (Horton, 2004, p. 820). This statement described six specific allegations including the accusation that proper ethics approval had not been granted for the study, that the participants in the study were not selected in the unbiased manner described in the article, and that Wakefield was linked in multiple ways to a legal case being made on behalf of parents who claimed their children were injured by vaccines (i.e., children of these families were included as participants, data were shared with lawyers prior to publication in The Lancet, and Wakefield personally received a substantial payment related to the legal case). The statement concluded that some allegations did not have supporting evidence and that other allegations could be rectified with a “course of full disclosure” published in the same issue (Horton, 2004, p. 821). However, after further investigation by other bodies (e.g., the UK General Medical Council’s Fitness to Practise Panel), the editors of The Lancet formally retracted Wakefield et al. (1998) in 2010 (Editors of The Lancet, 2010).

Even though the unethical conduct related to Wakefield et al. (1998) has been handled in the scientific community (e.g., the article has been retracted, subsequent studies have provided evidence that there is no link between ASD and vaccines [for sample evidence, see Taylor et al., 2014]), the consequences remain in the rest of society as vaccine hesitancy continues and the public’s distrust in science persists (DeStefano & Shimabukuro, 2019).

Development of Foundational Research Ethics Documents and Policies (1953–1991)

The release of the Nuremberg Code arguably marked the beginning of the formalization of research ethics expectations as described in previous sections. However, the Nuremberg Code was limited in authority; it was not an official policy statement of any professional organization. In the 1950s and 1960s, steps were taken to turn the Nuremberg Code into something enforceable within professions and legal statutes.

The Ethics Code of the American Psychological Association (1953)

By the middle of the 20th century, the American Psychological Association (APA) was experiencing a shift in membership from primarily scientists and academics to a balance between scientists and practitioners and a shift in focus from scientific affairs to those of clinical practice (West, 2008). With this shift came the development of Ethical Standards of Psychologists, an ethics code for members of the APA (APA, 1953). (For an in-depth account of debate surrounding the establishment of an ethics code for the APA, see Joyce and Rankin (2010)). Section 4 of Ethical Standards of Psychologists included three items related to research ethics: (1) Maintaining standards of research; (2) Protecting welfare of research subjects; and (3) Reporting research results (APA, 1953). With the release of this document, members of the APA who were engaged in unethical research activities could be held accountable by their professional organization (Joyce & Rankin,