Little Albert experiment
The Little Albert experiment was a case study showing empirical evidence of classical conditioning in humans. The study also provides an example of stimulus generalization. It was carried out by John B. Watson and his graduate student, Rosalie Rayner, at Johns Hopkins University. The results were first published in the February 1920 issue of the Journal of Experimental Psychology.
After observing children in the field, Watson hypothesized that the fearful response of children to loud noises is an innate unconditioned response. He wanted to test the notion that by following the principles of the procedure now known as "classical conditioning", he could use this unconditioned response to condition a child to fear a distinctive stimulus that normally would not be feared by a child (in this case, furry objects).
The aim of Watson and Rayner was to condition a phobia in an emotionally stable child. For this study they chose a nine-month old infant from a hospital referred to as "Albert" for the experiment. Watson followed the procedures which Pavlov had used in his experiments with dogs.
Before the experiment, Albert was given a battery of baseline emotional tests: the infant was exposed, briefly and for the first time, to a white rat, a rabbit, a dog, a monkey, masks (with and without hair), cotton, wool, burning newspapers, and other stimuli. Albert showed no fear of any of these items during the baseline tests.
For the experiment proper, Albert was put on a mattress on a table in the middle of a room. A white laboratory rat was placed near Albert and he was allowed to play with it. At this point, Watson and Rayner made a loud sound behind Albert's back by striking a suspended steel bar with a hammer each time the baby touched the rat. Albert responded to the noise by crying and showing fear. After several such pairings of the two stimuli, Albert was presented with only the rat. Upon seeing the rat, Albert got very distressed, crying and crawling away. Apparently, the infant associated the white rat with the noise. The rat, originally a neutral stimulus, had become a conditioned stimulus, and it was eliciting an emotional response (conditioned response) similar to the distress (unconditioned response) originally given to the noise (unconditioned stimulus.) 
In further experiments, Little Albert seemed to generalize his response to the white rat. He became distressed at the sight of several other furry objects, such as a rabbit, a furry dog, and a seal-skin coat, and even a Santa Claus mask with white cotton balls in the beard. However, this stimulus generalization did not extend to everything with hair. 
It should be noted that Watson's experiment had many failings by modern standards. For example, a single subject and no control subjects. Most importantly, such an experiment would never be allowed under current law and regulations, as it clearly subjected the infant to severe stress and potential long-term psychological damage.
Albert was about one year old at the end of the experiment, and he reportedly left the hospital shortly thereafter. Though Watson had discussed what might be done to remove Albert's conditioned fears, he had no time to attempt such desensitization with Albert, and it is likely that the infant's fear of furry things continued post-experimentally.
Watson later gave a series of weekend lectures describing the Little Albert study. One of these lectures was attended by Mary Cover Jones, which sparked her interest in pursuing graduate work in psychology. She became known as the "Mother of Behavior Therapy" following a study she conducted on a three-year-old.
Identifying Little Albert
According to some textbooks, Albert's mother worked in the same building as Watson and didn't know the tests were being conducted. When she found out, she took Albert and moved away, letting no one know where they were going. A 2009 report, however, disputes that. The original report had stated that the baby's mother was a wet nurse at the hospital, who may have felt coerced and unable to turn down a request for her baby to be used in Watson's experiment.
In 2009, psychologists Hall P. Beck and Sharman Levinson published an article in which they claimed to have discovered the true identity of "Albert B." After reviewing Watson's correspondence and publications, as well as research in public documents (such as the 1920 United States Census and state birth and death records), Beck argued that "Albert B." was a pseudonym for Douglas Merritte, the son of Arvilla Merritte, then a woman who appears to have been a wet nurse at the Harriet Lane Home. Recent research has shown, however, that Douglas Merritte may not have been "Little Albert", and may in fact have been young William Barger.
The identity claimed by Beck, Levinson, and Irons has been contested by psychology researchers, Russ Powell and Nancy Digdon, as well as Watson scholar, Ben Harris, who offer an alternative identity based on available data. William Barger had been born within a day of Merritte, was known by friends and family as "Albert" (even though his given name was William), and his mother had also worked at the hospital where the experiment was conducted. In addition, his size and developmental condition much more closely matched the experiment's documentation of the subject baby's condition. Through the use of a professional genealogist, the researchers learned Barger had died in 2007 at age 87 and identified one close living relative, a niece. In an interview, Barger's niece stated that she and her uncle had been quite close throughout his life, acknowledged Barger's antipathy toward dogs as a well-known fact that family members would tease him about (the researchers noted there was no way to determine whether or not this behavior was linked to Watson's experiment), and stated that she did not recall any other phobias. The researchers concluded that Barger was unaware of his role as an infant test subject.
As recounted above, Albert's conditioned fear was never extinguished. Although he probably continued to fear various furry objects for a time, he would likely have been desensitized by his natural environments later in life. Nonetheless, the experiment today would be considered unethical according to the American Psychological Association's ethic code, and legislation has been passed to prevent such potentially harmful experiments. In the early 1970s, following widely publicized cases of research abuse, The National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research (NCPHS) was created to study issues surrounding the protection of humans in research. In 1979, the Commission issued a report entitled "Ethical Principles and Guidelines for the Protection of Human Subjects of Research" (commonly called the "Belmont Report"), which provided the ethical framework with which current federal regulations for the protection of human participants in research are based on. Under the NCPHS standards set in the late 1970s, an experiment such as Watson's would not have been allowed. There are also regulations now put in place by the Health Insurance Portability and Accountability Act of 1996 and the Public Health Service Act, as well as required education since 2000 in the use of human research participants required by the National Institutes of Health.
A detailed review of the original study and its subsequent interpretations by Ben Harris (1979) stated:
Critical reading of Watson and Rayner's (1920) report reveals little evidence either that Albert developed a rat phobia or even that animals consistently evoked his fear (or anxiety) during Watson and Rayner's experiment. It may be useful for modern learning theorists to see how the Albert study prompted subsequent research [...] but it seems time, finally, to place the Watson and Rayner data in the category of "interesting but uninterpretable" results.
It is difficult to be certain exactly what happened during the Little Albert Experiment since concrete evidence and scientific records are lacking. Though a film was shot during the experiment, textbooks interpret the movie differently. Various sources give contradicting accounts of events that took place, and they raise questions about exactly what stimuli were used, which stimuli the baby came to fear, and what happened to the child after the experiment. It was said that most textbooks "suffer from inaccuracies of various degrees" while referring to Watson and Rayner's study. Texts often misrepresent, exaggerate, or minimize the range of Albert's post-conditioning fears.
- Hill, G. (2009). AS & A Level Psychology Through Diagrams, pg 27.
- Watson & Rayner, 1920, p. 1
- Anyone—Regardless of Their Nature—Can Be Trained to Be Anything; Watson, John B.; "Big Ideas Simply Explained: The Psychology Book." London: Dorling Kindersley Publishing, Inc., 2012; Credo web reference-Subscription Required; accessed September 23, 2013.
- Steven Schwartz; Classic Studies in Psychology; Palo Alto: Mayfield Publishing,1986; print.
- Hill, pg 177.
- (Harris, 1979).
- Reiss; pg 206–216
- H. P.; Levinson, S., & Irons, G.; 2009; pp.605–614"
- Beck, H. P., Levinson, S., & Irons, G. (2009). "Finding Little Albert: A journey to John B. Watson's infant laboratory". American Psychologist, 64, 7: 605–614.
- Powell, Russell A.; Digdon, Nancy; Harris, Christopher; Smithson, Ben (2014). "Correcting the record on Watson, Rayner, and Little Albert: Albert Barger as "Psychology’s lost boy"". American Psychologist (American Psychological Association) 69 (6): 600–611. doi:10.1037/a0036854. Retrieved 8 June 2015.
- Digdon, Nancy; Powell, Russell A.; Harris, Ben (2014). "Little Albert’s Alleged Neurologicial Impairment: Watson, Rayner, and Historical Revision". History of Psychology (American Psychological Association) 17 (4): 312–324. doi:10.1037/a0037325. Retrieved 8 June 2015.
- Bartlett, T. (June 2, 2014). "The Search for Psychology's Lost Boy: In 2009 the Decades-old Mystery of 'Little Albert' was Finally Solved... or Was It?". The Chronicle of Higher Education.
- "Whatever Happened to Little Albert?". Edmonton, Alberta: MacEwan University News. June 2, 2014. Retrieved August 30, 2014.
- American Psychology Association; 2013.
- National Institute of Health
- American Psychology Association; 2013
- Note: It is now considered unethical to evoke reactions of fear in humans under laboratory circumstances, except when the participant has given informed consent to being purposely horrified as part of the experiment. The standards dictate that experiments should not cause the human participants to suffer unnecessary distress or to be in any way physically harmed. The welfare of the human participants must always be the paramount consideration in any form of research, and this is especially true with specially protected groups such as children.
- Ben Harris. "Whatever Happened to Little Albert?". Retrieved 30 August 2010.
- Harris, 2011, 10
- American Psychological Association (2010). Ethical Principles of Psychologists and Code of Conduct.
- Bartlett, T. (2014, June 2).  The Search for Psychology's Lost Boy: In 2009 the decades-old mystery of 'Little Albert' was finally solved. Or was it? Chronicle of Higher Education.
- Bartlett, T. (2012). A New Twist in the Sad Saga of Little Albert.
- Cover Jones, M. (1924). A Laboratory Study of Fear: The Case of Peter. Pedagogical Seminary, 31, pp. 308–315.
- DeAngelis, T. (2010). 'Little Albert' regains his identity. Monitor on Psychology, 41, 1. pp. 10.
- Digdon, Nancy; Powell, Russell A.; Harris, Ben "Little Albert's alleged neurological impairment: Watson, Rayner, and Historical Revision" History of Psychology, Jul 28, 2014, No Pagination Specified. doi: 10.1037/a0037325
- Fridlund, A. J., Beck, H. P., Goldie, W. D., & Irons, G. (2012). Little Albert: A neurologically impaired child. History of Psychology. doi: 10.1037/a0026720
- Harris, B. (2014). Rosalie Rayner, feminist? Revista de Historia de la Psicología, 35, 61-69.
- Harris, B. (2011). Letting go of Little Albert: Disciplinary memory, history, and the uses of myth. Journal of the History of the Behavioral Sciences, 47, 1, pp. 1–17. doi:10.1002/jhbs.20470
- Harris, B. (1979). Whatever Happened to Little Albert? American Psychologist, 34, 2, pp. 151–160.
- Hill, G. (2009). AS & A Level Psychology Through Diagrams, Oxford University Press.
- Hock, R. (2005). Forty Studies That Changed Psychology: Explorations into the History of Psychological Research. 5th ed. New Jersey: Prentice Hall.
- Kasschau, R. (2001). Understanding psychology. Columbus, OH: Glenco/McGraw-Hill.
- National Institute of Health (2000). Required Education in the Protection of Human Research Participants.
- Powell. R. A., Digdon, N., Harris, B. & Smithson, C. (in press). Correcting the record on Watson, Rayner and Little Albert: Albert Barger as ‘Psychology’s lost boy.’ American Psychologist.
- Reiss, B. K. (1990). A biography of Mary Cover Jones. Unpublished doctoral dissertation. The Wright Institute, Los Angeles, CA.
- Watson, J.B. and Rayner, R. (1920). Conditioned emotional reactions. Journal of Experimental Psychology, 3, 1, pp. 1–14.