Case Studies

(Naturalistic Methods) Case Studies

Whereas observational research generally assesses the behavior of a relatively large group of people, sometimes the data are based on only a small set of individuals, perhaps only one or two. These qualitative research designs are known as case studies—descriptive records of one or more individual’s experiences and behavior. Sometimes case studies involve normal individuals, as when developmental psychologist Jean Piaget (1952) used observation of his own children to develop a stage theory of cognitive development. More frequently, case studies are conducted on individuals who have unusual or abnormal experiences or characteristics or who are going through particularly diffi cult or stressful situations. The assumption is that by carefully studying individuals who are socially marginal, who are experiencing a unique situation, or who are going through a diffi cult phase in their life, we can learn something about human nature. 

        Sigmund Freud was a master of using the psychological diffi culties of individuals to draw conclusions about basic psychological processes. One classic example is Freud’s case study and treatment of “Little Hans,” a child whose fear of horses the psychoanalyst interpreted in terms of repressed sexual impulses (1959). Freud wrote case studies of some of his most interesting patients and used these careful examinations to develop his important theories of personality. 

        Scientists also use case studies to investigate the neurological bases of behavior. In animals, scientists can study the functions of a certain section of the brain by removing that part. If removing part of the brain prevents the animal from performing a certain behavior (such as learning to locate a food tray in a maze), then the inference can be drawn that the memory was stored in the removed part of the brain. It is obviously not possible to treat humans in the same manner, but brain damage sometimes occurs in people for other reasons. “Split-brain” patients (Sperry, 1982) are individuals who have had the  two hemispheres of their brains surgically separated in an attempt to prevent severe epileptic seizures. Study of the behavior of these unique individuals has provided important information about the functions of the two brain hemispheres

in humans. In other individuals, certain brain parts may be destroyed through disease or accident. One well-known case study is Phineas Gage, a man who was extensively studied by cognitive psychologists after he had a railroad spike blasted through his skull in an accident. An interesting example of a case study in clinical psychology is described by Rokeach (1964), who investigated in detail the beliefs and interactions among three schizophrenics, all of whom were convinced they were Jesus Christ.

           One problem with case studies is that they are based on the experiences of only a very limited number of normally quite unusual individuals. Although descriptions of individual experiences may be extremely interesting, they cannot  usually tell us much about whether the same things would happen to other individuals in similar situations or exactly why these specific reactions to these events occurred. For instance, descriptions of individuals who have been in a stressful situation such as a war or an earthquake can be used to understand how they reacted during such a situation but cannot tell us what particular longterm effects the situation had on them. Because there is no comparison group  that did not experience the stressful situation, we cannot know what these individuals would be like if they hadn’t had the experience. As a result, case studies provide only weak support for the drawing of scientifi c conclusions. They may, however, be useful for providing ideas for future, more controlled research.